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GRIPCHALKERS l TABLE MENU HOLDERS FOR Pubs, Venues & Restaurants
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We use next day courier service in UK.
Simply upload your design to the Upload tab at the top of the page using. If you are unable to upload through Upload Tab simply email or transfer to firstname.lastname@example.com.
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If you need us to design you a artwork simply email email@example.com with your details and photos. Our designers are proud to do your artwork design quickly. Our designer team is well experienced and qualified and can serve stylish, eye catching and modern designs at every subject. Artwork creation will take between 1-2 days.
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bed and breakfast(redirected from bed)
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Bed and Breakfast
A small hotel, often a private home, that provides breakfast in addition to lodging. Bed and breakfasts are usually marketed to couples and families for romantic getaways or vacations. They often are found in rural areas, though this is not always the case.

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Material: PU
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Our return policy lasts for 14 days of you receiving your order. We only replace item that is defective or damaged. If you need to exchange for another different item, please refer to return process. Before returning your item please contact customer service at email@example.com


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Beginning iPhone Games Development
Apress, May 14, 2010 - Computers - 728 pages
iPhone games are hot! Just look at the numbers. Games make up over 25 percent of total apps and over 70 percent of the most popular apps. Surprised? Of course not! Most of us have filled our iPhone or iPod touch with games, and many of us hope to develop the next best-selling, most talked-about game.
You've probably already read and mastered Beginning iPhone 3 Development; Exploring the iPhone SDK, the best-selling second edition of Apress's highly acclaimed introduction to the iPhone and iPod touch by developers Dave Mark and Jeff LaMarche. This book is the game-specific equivalent, providing you with the same easy-to-follow, step-by-step approach, more deep technical insights, and that familiar friendly style.
While games are all about fun, at the same time, they're serious business. With this Beginning iPhone Games Development book, you're going to roll up your sleeves and get your hands dirty with some hardcore coding. While you may have written games before, this book will take you further, immersing you in the following topics:Game graphics and animation with UIKit, Quartz, Core Animation, and OpenGL ES Game audio with OpenAL, MediaPlayer Framework, AV Foundation, and AudioSession Game networking with GameKit, Bonjour, and Internet sharing
For those looking for iPad game development coverage and/or iOS 5 SDK specific game coverage, check out the published Beginning iOS 5 Games Development by Lucas Jordan from Apress.What you'll learn Efficient methods for drawing in 2D and 3D to the iPhone screen Game-specific animation techniques with Core Animation To use OpenGL ES for more complex and realistic gaming backgrounds and action Numerous ways to add music to enhance the gaming experience How to give your users access to their iPhone libraries from within games The tools and techniques of 3D audio for creating even more realistic gaming experiences How to do networking right, including two-player games over Bluetooth and multiplayer games over Wi-Fi Who this book is for
All game developers who desire to create iPhone and/or iPod touch games.Table of Contents A Revolutionary Gaming Platform Games for Everyone, Anytime, Anywhere Developing iPhone Games Peeking Inside the iPhone Toolbox Moving Images on a Small Screen—UIKit Controls She Shoots, She Hits, She Scores! Flipping Out and Sweeping Away with Core Animation OpenGL Basics: Wrapping Your Head Around the OpenGL AP Putting It Together: Making a Game in OpenGL The Next Steps: Atlases, Sprites, and Particles—Oh My Introduction to Core Audio Making Noise with OpenAL 3D Audio—Turning Noise into Game Sound Streaming: Thumping, Pulse-Quickening Game Excitement Networking for iPhone Games: Introductio Going Head to Head Party Time Connecting with the Outside World Putting It All Together: Now Comes the Fun Part
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Beginning iPhone Games Development
PJ Cabrera,Peter Bakhirev,Ian Marsh,Ben Smith,Eric Wing,Scott Penberthy,Stuart Marsh,Roderick Smith
No preview available - 2010


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Comprehensive and adaptable condition monitoring for optimised condition and process monitoring
Extensive and customisable condition monitoring
VSE150 is a 6-channel diagnostic system designed to evaluate 4 dynamic signals (e.g. rotational acceleration) and 2 analogue inputs. The new VSE15x family provides different fieldbus interfaces to exchange data with a PLC. This makes it possible to display the measuring values directly on the control system and optimally adapt the monitoring functions to the operating states and processes of the machine. In addition to the fieldbus, 2 fast digital switching outputs (response time ≤1 ms) are provided for time-critical alarms.
Reduced network complexity saves time and money
The direct PLC connection via fieldbus allows auxiliary parameters (e.g. rotational speed and triggers for operating states) as well as non-time-critical alarms from condition monitoring to be exchanged over the bus. This not only reduces wiring complexity but also saves the cost of providing the corresponding inputs/outputs on the PLC.


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(c) Pocumtuck Valley Memorial Association, Deerfield MA. All rights reserved.
Contact us for information about using this image.
In 1908 at the Deerfield Annual Summer Exhibition in Deerfield, Massachusetts, the Deerfield Society of Blue and White Needlework exhibited "Panel for screen, The Last Rose of Summer" and offered it for sale at $25.00. The appliqued and embroidered panel was intended to set in a wood frame and be made into a screen.
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text: Sacred Destinations Destinations France Paris Notre Dame Cathedral Notre Dame Cathedral Photos 25936 × share full URL share short URL embed link code photo 95 of 96 Previous | Next Portal of the Virgin (c.1220) The Portal of the Virgin, dedicated to the patroness of the cathedral, is usually the exit door for modern visitors. It was sculpted second of the three portals, in the 1210s-1220s. The tympanum features the Coronation of the Virgin, with an angel crowning Mary while Christ blesses her and gives her a scepter. The top lintel depicts the Death of the Virgin - Mary lies on her death bed (corresponding to the Nativity bed in the same position on the right portal) surrounded by Jesus and the Twelve Apostles. Two angels at her head and feet lift up her up to Heaven. The bottom lintel has three Old Testament prophets (left) and three Old Testament kings (right), all holding scrolls representing prophecies of Christ. Credit: Holly Hayes


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April was another big month of finds in the record store and online…..here's what I got in April…..
Sevendust – Black Out The Sun (2013) – $10
Kvelertak – Meir (2013) – $10
First trip of the month was a quick one to my usual record store just to pick up the latest Sevendust and Kvelertak CDs. Nothing really exciting or exotic about this purchase but I got two new albums for $10 each and saved $6 on each one compared to the regular price.
Michael Schenker Group – Temple Of Rock Live In Europe (2CD) (2013) – $13
Michael Schenker Group – Temple Of Rock Live In Europe (DVD) (2013) – $13
Queen – Hungarian Rhapsody (2CD/BluRay) (2013) – $26
Royal Hunt – 20th Anniversary Special Edition (3CD/DVD) (2013) – $14.30
The second trip of the month was for the Newbury Comics 35th Anniversary sale where everything was 35% off. This was where I was going to make some long overdue expensive purchases! I didn't have a lot of time though so I went to my usual location close to the house and I picked up the latest Michael Schenker live album and DVD ($13 each, saved $7 each) the Queen – Hungarian Rhapsody (2CD/BluRay) ($26, saved $14) and the Royal Hunt 20th Anniversary (3CD/DVD) ($14.30, saved $7.70). I've had my eye on these for a while and I knew the sale was coming so I put all of them together on one shelf in the Music DVD/BluRay section and walked in, grabbed them, paid quick and went home.
Dio – Magica (picture disc) (2013) – $22
Skid Row – United World Rebellion Chapter 1 (2013) – $6
Kobra & The Lotus – s/t (2013) – $13
Ghost B.C. – Infestissumam (Deluxe Edition) (2013) – $12
Warbeast – Destroy (2013) – $12
Into Eternity – The Scattering Of Ashes (2006) – $4 used
Rainbow – Down To Earth (1979/1997 reissue) – $8 used
Iced Earth – Live In Ancient Kourion (2CD/DVD) – $17
I never miss Record Store Day and there was a line again this year at the Newbury Comics North Attleboro store. I'm not a big vinyl collector, just select Heavy Metal vinyl, so I only had my eye on one thing…..the Dio Magica picture disc. So, while everyone was going for these limited edition vinyl releases for RSD, I went over to the CDs and got what I needed. Saved $17 on all the new releases by getting them on sale plus I scored an Into Eternity CD I needed for $4 used and the 1999 remaster of Rainbow's Down To Earth from 1979 (Graham Bonnet on vocals) for $8 used. I browsed around for a bit while the fury of the vinyl frenzy died down, then I walked over and plucked my Dio pic disc from the bin for $22. A little expensive but a limited edition numered copy.
Whitesnake – Made In Japan (2CD/DVD) (2013) – $15
Cauldron – Tomorrow's Lost (2013) – $14
Tom Keifer – The Way Life Goes (2013) – $10
George Lynch – Legacy E.P. (2012) – $6
Last trip of the month to the record store to grab the new Whitesnake (2CD/DVD), Tom Keifer and Cauldron albums on sale, saving $13 total off the regular sticker price and adding in a George Lynch E.P. for $6 new. Quick, easy and home with new treasures.
Blue Murder – s/t (1989) – $5 used
Faster Pussycat – s/t (1987) – $5 used
Faster Pussycat – Whipped! (1992) – $5 used
HARD – Time Is Waiting For No One (2010) – $10 used
Signal – Loud & Clear (1989) – $10 used
Tygers Of Pan Tang – Ambush (2012) – $9 used
Ebay was a good place in April because I picked up some harder than usual to find CDs. I got the Blue Murder and both Faster Pussycats from the same seller so I saved on shipping as well as price! Everything mint and cheap…..goodbye to those old cassettes! The HARD album replaces a digital promo the label sent me back in 2010, a little pricey but there was $3 shipping added to the $7 winning bid. The same seller sold me the Signal album as well so the shipping was free on that because I bought the HARD disc. I've been trying to track down an original copy of Loud & Clear for years but there's always a bidding war upping the price. There have been a few reissues along the way as well but this copy was original and mint condition so I didn't mind paying the extra money for it. Last Ebay find was the last Tygers of Pan Tang album, Ambush, from 2012. $9 used instead of $20 import price? A great deal!
Cheap Trick – The Complete Epic Albums Collection Box Set (2012), Live At Budokan (30th Anniversary Box Set) (2008) – $100
I registered at Pop Market.com years ago and there are good deals from time to time. I've been eyeing the Cheap Trick box sets for a long time and I was actually watching both on separate auctions on Ebay but this offer of both together for $100 plus free shipping was a great deal. I pulled the trigger immeadiately.
Y&T – Earthshaker (1981), Mean Streak (1983), In Rock We Trust (1984), Down For The Count (1985) (all Japanese imports) – $75
My last deal was for four Japanese imports of Y&T albums that I didn't have. I was watching these for $25 each (that's $22 + $3 shipping each disc) on Ebay but I waited because there were no bidders and the listings were flooded with the same CDs. Once the auctions for all four ended, I privately contacted the seller and politely requested a non-Ebay private sale at a lower price. $75 plus free shipping was my offer and the seller took it. I saved $25 off the initial Ebay listings and I can live with that, especially for mint Japanese imports with all the inserts inside!
Total = $444.30
Total (year) = $822.80
Average Price (per item) = $11.75
Total CDs (year) = 61
Total DVDs & BluRays (year) = 3
Total LPs (year) = 1
Total Box Sets (year) =5


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The journey continues...
I was having a conversation with my son Jay, who is a Business Coach, and we were discussing what it is that makes him distinct from other coaches. Specifically it is his ability to "listen for what's missing."
The interesting thing is I was right in the middle of a struggle with my own dream, Bohemian Romance, the venue. So I asked my son, "What's missing?" and to my surprise he nailed it!
I was struggling with how to articulate the purpose of this venue and very simply he said "It's a place for ideas to arise. An artistic backdrop where one's own self expression can show up. A conduit for possibility."
Thanks Jay!
So as I continue in my quest to bring this vision about, I just want to remind you of the sale on my prints, buy one get one free, and the drawing for a free painting which will be held on April 30th.
Friday, April 18, 2014
Posted by femme hesse at 8:56 PM 5 comments
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Magmatic arc fault systems, deformation partitioning and emplacement of granitic complexes in the Coastal Cordillera, north Chilean Andes (25 degrees, 30 minutes South to 27 degrees South)
J. Grocott, and G. K. Taylor
Journal of the Geological Society (London) v. 159 (4), pp. 425-443.
Abstract: Three fault systems were responsible for Permian to Late Cretaceous deformation of the overriding plate of the Andean convergent margin in the Coastal Cordillera of northern Chile ((25 degrees, 30 minutes South to 27 degrees South). Displacements were linked to crustal growth expressed by the emplacement of a sequence of magmatic arcs. The Tigrillo Fault System, active from Triassic to Early Cretaceous time, was characterized by arc-normal extension with increasing left-oblique extension (transtension) from Early Jurassic to Early Cretaceous time. Stretching of the crust created space for Triassic, Early Jurassic and Early Cretaceous arc basins where epiclastic, volcaniclastic and volcanic sequences accumulated in continental to shallow marine environments. Tabular plutonic complexes were emplaced by roof uplift-floor subsidence that allowed a vertical transfer of material in the crust without significant horizontal extension. The Atacama Fault System was initiated at c.132 Ma as a (mainly) left strike-slip fault during left-oblique extension of the margin. Elongate, tabular plutonic complexes were emplaced within the Atacama Fault System between c. 132 and c. 106 Ma, again by roof uplift-floor subsidence mechanisms. Ductile-brittle transitions in synplutonic mylonitic rocks of the Atacama Fault System provided the setting for Kiruna-type Fe-apatite, and Fe oxide (with Cu and/or Au) ores. The Chivato Fault System was active as an extensional fault system at the eastern side of the Coastal Cordillera during displacement on the Tigrillo Fault System and later, between c.125 and c.93 Ma, as a partitioned left-oblique extensional fault system. In post-Early Cretaceous time the Chivato Fault System was inverted by left-oblique contraction (transpression) when NW-trending transfer faults, some probably reactivated lateral ramps in the Tigrillo Fault System, accommodated clockwise vertical-axis rotations of 35-45 degrees. Contraction inverted the Atacama Fault System and Tigrillo Fault System and was responsible for west-vergent, thin-skinned, fold-thrust deformation in stratified rocks throughout the margin.
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Folds/Faults/Ductile Shear Zones,
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Igneous Processes,
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Record numbers Vote!
WoW! The figures are in and (somewhat belatedly) I am amazed that against a backdrop of restructuing the Youth Voice & Engagement team have managed to encourage and support a record number of young people to participate in the West Sussex Youth Cabinet & UK Youth Parliment elections.
It's the 11th year elections have been held and they have grown more sophisticated over time with an electronic voting system now in place. However we have mixed and matched this with the more traditional system of ballot papers to ensure everyone can participate. A total of 20,088 young people voted casting a total of 39,163 in both elections, meaning that 23 percent of young people in West Sussex aged between 11 and 19-years-old took part in the democratic process – an amazing accomplishment.
Candidates included young parents, young carers, and young people with multiple needs as the team worked to ensure that as many young people were engaged in the process as possible. There were also some polling stations in foyers, youth centres and mobile provisions.
Almost all the young people voted on to the Youth Cabinet were new to the role and a weekend residential (more later) was planned to start inducting them into their roles.
So – congratulations to all involved and lets hope that this is the beginning of an amazing year for youth voice!!


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Hamas praises deadly West Bank shooting
JERUSALEM (AP) — The prime minister of the Hamas-ruled Gaza Strip on Tuesday praised a shooting that killed an Israeli and wounded his wife and son as they drove through the West Bank the previous evening en route to a Passover meal.
Speaking in Gaza, Ismail Haniyeh said the attack outside the city of Hebron "brought back life to the path of resistance" against Israel and warned of more attacks in the Palestinian territory.
Monday's shooting came just before the start of the weeklong Jewish holiday of Passover, as families gather after sundown for a traditional meal called a Seder. No one claimed responsibility for the attack.
Hamas and Israel are bitter enemies. They have engaged in several rounds of fighting since the militant Islamic group seized power in Gaza in 2007 after ousting forces loyal to the Palestinian Fatah party, led by President Mahmoud Abbas, in fierce street battles. The two Palestinian groups have not reconciled despite several attempts and Hamas now rules Gaza while Abbas governs part of the West Bank.
"We tell the enemy and anyone who thinks he is able to tame the West Bank ... the West Bank will be the future point of our struggle with the enemy," Haniyeh said.
Israeli media said the wounded woman was told in hospital that her 40-year-old husband was killed. It said their wounded son is nine years old.
Israel's public security minister, Yitzhak Aharonovitch, visited the wounded at a Jerusalem hospital.
"A harsh incident, I have been updated that everybody is making the efforts to capture the terrorists, the murderers. I assume that the security forces will get their hands on the murderers," he said.
The attack could further complicate U.S. attempts to salvage the troubled Israeli-Palestinian peace talks. The Palestinians want to establish a state in the West Bank, Gaza Strip and east Jerusalem, lands Israel captured in the 1967 Mideast war from Jordan and Egypt.
Two decades of Israeli-Palestinian negotiations have failed to settle the conflict, and the latest U.S. mediation attempt, launched last year by Secretary of State John Kerry, also seems on the verge of collapse.
Kerry has said he wants to see a deal, or at least the outlines of one, by the end of April. But the two sides remain locked in a dispute over the terms of extending talks, without having made any apparent progress on issues such as borders and security arrangements.
Attacks like Monday's were common in the West Bank during Israeli-Palestinian fighting last decade, but the level of violence dropped significantly in recent years.
Israeli human rights group B'Tselem "strongly condemned" the shooting, adding that "attacks against civilians within Israel's borders are no different from attacks against settlers living in the West Bank."
"The argument that there is justification for killing settlers as part of the struggle against Israeli occupation is both legally and morally groundless," it said, adding that all civilians must be protected.
In 2002, at the height of Israeli-Palestinian fighting, a Palestinian suicide bomber blew himself up at a Passover Seder at a hotel, killing 30 people and wounding over 100.
Associated Press Writer Ibrahim Barzak contributed to this report from Gaza City, Gaza Strip.


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Rates include unlimited mileage, Value added tax (VAT), Comprehensive coverage with a deductible of 1.200 € per loss, Third-party liability insurance with a global limit of indemnity of 50 Mio. €, Fiat mobility program + emergency service, Awning, Dethleffs safety package, Air conditioning in driver's cabin, Bicycle rack (not suitable for E-bikes), Outside cleaning, 2 bottles of gas (1 full bottle and 1 used bottle), Balancing wedges, CI cable, Cable reel, WC chemicals, Water hose/ watering can.
Technical Details:
Sleeps: 6
Seats: 6
Length: 651cm
Width: 233cm
Height: 319cm
Internal Height: 198cm
Load capacity: 554kg
Engine: 2,3 l, 96 kW/130 PS
Gear box: Manual
Fuel: Diesel
Average Consumption ca.: 10-12 L / 100 km
Servo steering: Yes
Brake booster: Yes
Fuel cell ca.: 90 L
Passage driving cab: Yes
Fixation childseat back: Yes
Shower: Yes
Toilet: Yes
Basin: Yes
Dual battery system: Yes
Power supply: 12 V und 230 V* (*only while connected extern)
Fridge / Freezer ca.: 142 L / 15 L
Cooker: 3-Flames
Water tank incl. Boiler ca.:107 L
Wast water tank ca. :90 L
Propane gas: 2x 11 kg
Air condition driving cab: Yes
Awning: Yes
Bicycle rack max. 60 kg load: Yes
Bed Dimension:
Double: 210cm x 165cm
Double: 185cm x 130
Bunk: 210cm x 85cm
Bunk: 200cm x 80cm
Load Capacity:
Items are included in the load capacity: Driver, fuel, freshwater, 2 bottles of gas, cabledrum, awning, bicycle rack and Radio/CD.
The weights and measures on the registration document will apply.
Provided accessories:
Bicycle rack, Outside cleaning, Dish set, 2 bottles of gas (1 full bottle and 1 used bottle), Balancing wedges, CI cable, Cable reel, WC chemicals, Water hose
Please Note: For clients outside of the EU, please ensure that you have an international license. If you do not have an international license you need to send a copy of your national license to Mcrent prior to your vehicle collection. You cannot produce your national licence on the day of pick up without prior approval , copies of your license are required for insurance purposes.
Mcrent has recently changed insurers whom have stated that any driver from outside the EU or one that does not have an international licence must be processed for acceptance by the underwriters. As a matter of urgency please ensure that if you are outside of the European Union and do not have an International permit, you must send Mcrent a copy of your licence.
If you are due to pick up your vehicle at any of the Mcrent UK depots on a Saturday or Sunday and the drivers licence has not been pre-approved you will not be able to pick up the vehicle until Monday.
Please Note:
Campervan/Motorhome/4x4 Camper types displayed are for illustration purposes only. Actual vehicle may vary from photographs and illustrations.
The operator reserves the right to change specs and/or supply similar or higher class vehicle for the advertised price without notification.
***Please note floor-plans and interior shots are indicative only***
***The supplier reserves the right to substitute this vehicle model from the same category or from a higher category***
Click the images for larger previews


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Tim Langdell
Langdell's Edge trademark has been canceled by USPTO
The trademark for Edge which belonged to Edge Games founder Tim Langdell has been canceled by a court order.
Tim Langdell headlines
Langdell claims nearly 100 errors in Edge vs Future High Court ruling
The undaunted Tim Langdell has claimed a High Court ruling dismissing his trademark claims against Future was riddled with errors.
Langdell returns to games development with EDGEBobby 2
Lover of all-things EDGE-related Tim Langdell has now turned his head back to games development after his EDGE-related lawsuits against Future and EA. EDGE Games released the new title, known as EDGEBobby 2 – the "sequel to the highly popular classic game Bobby Bearing" – for iOS. It's available now for 59p, with PC, Mac […]
High court rules in Future's favour in Langdell copyright case
Future has been triumphant in its legal pursuit of notorious copyright hound Tim Langdell.
Langdell gets IGDA membership revoked due to "lack of integrity or unethical behavior"
Karma's a fun thing, isn't it?
Report - Langdell set to lose Edge trademarks
Following this week's news that Edge Games' injunction against EA over the use of the word 'Edge' was thrown out, it looks like boss Tim Langdell is set to lose the rest of his Edge-related trademarks.
Report - EA wins courtcase over "Edge" trademark
IG is reporting EA has won its courtcase against Edge Games over the trademark of the latter's namesake. For real this time.
EDGE back up on App Store
Mobigames' EDGE is now available again on Apple's App Store. Yours for £2.99.The game fell victim to Tim Langdell and his amazing trademark squatting, and has been in limbo for months.EA challenged Langdell recently, saying none of his claims to the "edge" name were valid as he wasn't currently using it for commercial purposes.Maybe he […]
EA makes legal move to stop Langdell trademark squatting
EA has petitioned the US Patent & Trademark Office to cancel a range of registrations associated with Edge Games, Inc.In the petition, EA's lawyers allege that Edge Games claims against companies using "Edge" in their titles aren't legitimate as they're not associated with a trademark used in active commerce.There are numerous citations in the 28-page […]
Tim Langdell left IGDA to avoid damaging it, believes all accusations "unfounded"
Former IGDA board of directors member Tim Langdell issued a statement about his recent departure, saying that he wasn't pushed out the door. Rather, he chose to vacate his position so that the IGDA wouldn't be caught in the crossfire between Langdell and those who are out to get him."I make this decision," he said, […]
IGDA boss: Tim Langdell stepped down for "personal reasons"
Speaking with VG247, IGDA Executive Director Joshua Caulfield said today that Tim Langdell decision to resign from the IGDA board of directors was for "personal reasons."Caulfield refused to elaborate further and directed us toward Langdell for a statement. Which we've done.There's more on the resignation here.
Tim Langdell resigns from IGDA board of directors
Tim Langdell, the trademark troll behind the recent Mobigames Edge fiasco, has resigned from the Independent Game Developers Association board of directors. This comes shortly after IGDA members started petitioning for his removal.Prior to taking the hint, Langdell abused his position by harassing anyone who used the name "Edge" as a game title. He hasn't […]
Tim Langdell latest
Langdell claims nearly 100 errors in Edge vs Future High Court ruling
High court rules in Future's favour in Langdell copyright case
Langdell gets IGDA membership revoked due to "lack of integrity or unethical behavior"
Tim Langdell left IGDA to avoid damaging it, believes all accusations "unfounded"


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Hartree-Fock Theory for Molecules
From NWChem
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Revision as of 13:48, 18 February 2011
The NWChem self-consistent field (SCF) module computes closed-shell restricted Hartree-Fock (RHF) wavefunctions, restricted high-spin open-shell Hartree-Fock (ROHF) wavefunctions, and spin-unrestricted Hartree-Fock (UHF) wavefunctions.
The SCF directive provides input to the SCF module and is a compound directive that encloses additional directives specific to the SCF module:
Wavefunction type
A spin-restricted, closed shell RHF calculation is performed by default. An error results if the number of electrons is inconsistent with this assumption. The number of electrons is inferred from the total charge on the system and the sum of the effective nuclear charges of all centers (atoms and dummy atoms, Geometry). The total charge on the system is zero by default, unless specified at some value by input on the CHARGE directive Total system charge.
The options available to define the SCF wavefunction and multiplicity are as follows:
SINGLET DOUBLET TRIPLET QUARTET QUINTET SEXTET SEPTET OCTET NOPEN <integer nopen default 0> RHF ROHF UHF
The optional keywords SINGLET, DOUBLET, ..., OCTET and NOPEN allow the user to specify the number of singly occupied orbitals for a particular calculation. SINGLET is the default, and specifies a closed shell; DOUBLET specifies one singly occupied orbital; TRIPLET specifies two singly occupied orbitals; and so forth. If there are more than seven singly occupied orbitals, the keyword NOPEN must be used, with the integer nopen defining the number of singly occupied orbitals (sometimes referred to as open shells).
If the multiplicity is any value other than SINGLET, the default calculation will be a spin-restricted, high-spin, open-shell SCF calculation (keyword ROHF). The open-shell orbitals must be the highest occupied orbitals. If necessary, any starting vectors may be rearranged through the use of the SWAP keyword on the VECTORS directive to accomplish this.
A spin-unrestricted solution can also be performed by specifying the keyword UHF. In UHF calculations, it is assumed that the number of singly occupied orbitals corresponds to the difference between the number of alpha-spin and beta-spin orbitals. For example, a UHF calculation with 2 more alpha-spin orbitals than beta-spin orbitals can be obtained by specifying
scf triplet ; uhf # (Note: two logical lines of input) ... end
The user should be aware that, by default, molecular orbitals are symmetry adapted in NWChem. This may not be desirable for fully unrestricted wavefunctions. In such cases, the user has the option of defeating the defaults by specifying the keywords ADAPT OFF and SYM OFF .
The keywords RHF and ROHF are provided in the code for completeness. It may be necessary to specify these in order to modify the behavior of a previous calculation (see NWChem Architecture for restart behavior).
SYM -- use of symmetry
SYM <string (ON||OFF) default ON>
This directive enables/disables the use of symmetry to speed up Fock matrix construction (via the petite-list or skeleton algorithm) in the SCF, if symmetry was used in the specification of the geometry. Symmetry adaptation of the molecular orbitals is not affected by this option. The default is to use symmetry if it is specified in the geometry directive (Geometry).
For example, to disable use of symmetry in Fock matrix construction:
sym off
ADAPT - symmetry adaptation of MOs
ADAPT <string (ON||OFF) default ON>
The default in the SCF module calculation is to force symmetry adaption of the molecular orbitals. This does not affect the speed of the calculation, but without explicit adaption the resulting orbitals may be symmetry contaminated for some problems. This is especially likely if the calculation is started using orbitals from a distorted geometry.
The underlying assumption in the use of symmetry in Fock matrix construction is that the density is totally symmetric. If the orbitals are symmetry contaminated, this assumption may not be valid -- which could result in incorrect energies and poor convergence of the calculation. It is thus advisable when specifying ADAPT OFF to also specify SYM OFF (Use of Symmetry).
TOL2E -- integral screening threshold
TOL2E <real tol2e default min(10e-7 , 0.01*thresh)>
The variable tol2e is used in determining the integral screening threshold for the evaluation of the energy and related Fock-like matrices. The Schwarz inequality is used to screen the product of integrals and density matrices in a manner that results in an accuracy in the energy and Fock matrices that approximates the value specified for tol2e.
It is generally not necessary to set this parameter directly. Specify instead the required precision in the wavefunction, using the THRESH directive (Convergence threshold). The default threshold is the minimum of 10 − 7 and 0.01 times the requested convergence threshold for the SCF calculation (Convergence threshold).
The input to specify the threshold explicitly within the SCF directive is, for example:
tol2e 1e-9
For very diffuse basis sets, or for high-accuracy calculations it might be necessary to set this parameter. A value of 10 − 12 is sufficient for nearly all such purposes.
VECTORS -- input/output of MO vectors
VECTORS [[input] (<string input_movecs default atomic>) || \ (project <string basisname> <string filename>) || \ (fragment <string file1> [<string file2> ...])] \ [swap [alpha||beta] <integer vec1 vec2> ...] \ [reorder <integer atom1 atom2> ...] \ [output <string output_filename default input_movecs>] \ [lock] [rotate <string input_geometry> <string input_movecs>]
The VECTORS directive allows the user to specify the source and destination of the molecular orbital vectors. In a startup calculation (see START), the default source for guess vectors is a diagonalized Fock matrix constructed from a superposition of the atomic density matrices for the particular problem. This is usually a very good guess. For a restarted calculation, the default is to use the previous MO vectors.
The optional keyword INPUT allows the user to specify the source of the input molecular orbital vectors as any of the following:
- ATOMIC -- eigenvectors of a Fock-like matrix formed from a superposition of the atomic densities (the default guess). See Atomic guess and Accuracy of initial guess.
- HCORE -- eigenvectors of the bare-nucleus Hamiltonian or the one-electron Hamiltonian.
- filename -- the name of a file containing the MO vectors from a previous calculation. Note that unless the path is fully qualified, or begins with a dot ("."), then it is assumed to reside in the directory for permanent files (see File directories).
- PROJECT basisname filename -- projects the existing MO vectors in the file filename from the smaller basis with name basisname into the current basis. The definition of the basis basisname must be available in the current database, and the basis must be smaller than the current basis. In addition, the geometry used for the previous calculations must have the atoms in the same order and in the same orientation as the current geometry.
- FRAGMENT file1 ... -- assembles starting MO vectors from previously performed calculations on fragments of the system and is described in more detail in Superposition of fragment molecular orbitals. Even though there are some significant restrictions in the use of the initial implementation of this method (see Superposition of fragment molecular orbitals), this is the most powerful initial guess option within the code. It is particularly indispensable for open shell metallic systems.
- ROTATE input_geometry input_movecs -- rotates MO vectors generated at a previous geometry to the current active geometry.
The molecular orbitals are saved every iteration if more than 600 seconds have elapsed, and also at the end of the calculation. At completion (converged or not), the SCF module always canonically transforms the molecular orbitals by separately diagonalizing the closed-closed, open-open, and virtual-virtual blocks of the Fock matrix.
The name of the file used to store the MO vectors is determined as follows:
- if the OUTPUT keyword was specified on the VECTORS directive, then the filename that follows this keyword is used, or
- if the input vectors were read from a file, this file is reused for the output vectors (overwriting the input vectors); else,
- a default file name is generated in the directory for permanent files (File directories) by prepending ".movecs" with the file prefix, i.e., "<file_prefix>.movecs".
The name of this file is stored in the database so that a subsequent SCF calculation will automatically restart from these MO vectors.
Applications of this directive are illustrated in the following examples.
Example 1:
vectors output h2o.movecs
Assuming a start-up calculation, this directive will result in use of the default atomic density guess, and will output the vectors to the file h2o.movecs.
Example 2:
vectors input initial.movecs output final.movecs
This directive will result in the initial vectors being read from the file "initial.movecs". The results will be written to the file final.movecs. The contents of "initial.movecs" will not be changed.
Example 3:
vectors input project "small basis" small.movecs
This directive will cause the calculation to start from vectors in the file "small.movecs" which are in a basis named "small basis". The output vectors will be written to the default file "<file_prefix.movecs>".
Once starting vectors have been obtained using any of the possible options, they may be reordered through use of the SWAP keyword. This optional keyword requires a list of orbital pairs that will be swapped. For UHF calculations, separate SWAP keywords may be provided for the alpha and beta orbitals, as necessary.
An example of use of the SWAP directive:
vectors input try1.movecs swap 173 175 174 176 output try2.movecs
This directive will cause the initial orbitals to be read from the file "try1.movecs". The vectors for the orbitals within the pairs 173-175 will be swapped with those within 174-176, so the resulting order is 175, 176, 173, 174. The final orbitals obtained in the calculation will be written to the file "try2.movecs".
The swapping of orbitals occurs as a sequential process in the order (left to right) input by the user. Thus, regarding each pair as an elementary transposition it is possible to construct arbitrary permutations of the orbitals. For instance, to apply the permutation (6789) we note that this permutation is equal to (67)(78)(89), and thus may be specified as
vectors swap 8 9 7 8 6 7
Another example, now illustrating this feature for a UHF calculation, is the directive
vectors swap beta 4 5 swap alpha 5 6
This input will result in the swapping of the 5-6 alpha orbital pair and the 4-5 beta orbital pair. (All other items in the input use the default values.)
The LOCK keyword allows the user to specify that the ordering of orbitals will be locked to that of the initial vectors, insofar as possible. The default is to order by ascending orbital energies within each orbital space. One application where locking might be desirable is a calculation where it is necessary to preserve the ordering of a previous geometry, despite flipping of the orbital energies. For such a case, the LOCK directive can be used to prevent the SCF calculation from changing the ordering, even if the orbital energies change.
The mapping of the MO's to the nuclei can be changed using the REORDER keyword. Once starting vectors have been obtained using any of the possible options, the REORDER keyword moves the MO coefficients between atoms listed in the integer list. This keyword is particularly useful for calculating localized electron and hole states.
This optional keyword requires a list containing the new atom ordering. It is not necessary to provide separate lists for alpha and beta orbitals.
An example of use of the REORDER keyword:
vectors input try1.movecs reorder 2 1 output try2.movecs
This directive will cause the initial orbitals to be read from the file "try1.movecs". The MO coefficients for the basis functions on atom 2 will be swapped with those on atom 1. The final orbitals obtained in the calculation will be written to the file "try2.movecs".
The following example shows how the ROTATE keyword can be used to rotate MO vectors calculated at geometry geom1 to geometry geom2, which has a different rotational orientation:
set geometry geom1 dft vectors input atomic output geom1.mo end task dft set geometry geom2 dft vectors input rotate geom1 geom1.mo output geom2.mo end task dft
Superposition of fragment molecular orbitals
The fragment initial guess is particularly useful in the following instances:
- The system naturally decomposes into molecules that can be treated individually, e.g., a cluster.
- One or more fragments are particularly hard to converge and therefore much time can be saved by converging them independently.
- A fragment (e.g., a metal atom) must be prepared with a specific occupation. This can often be readily accomplished with a calculation on the fragment using dummy charges to model a ligand field.
- The molecular occupation predicted by the atomic initial guess is often wrong for systems with heavy metals which may have partially occupied orbitals with lower energy than some doubly occupied orbitals. The fragment initial guess avoids this problem.
VECTORS [input] fragment <string file1> [<string file2> ...]
The molecular orbitals are formed by superimposing the previously generated orbitals of fragments of the molecule being studied. These fragment molecular orbitals must be in the same basis as the current calculation. The input specifies the files containing the fragment molecular orbitals. For instance, in a calculation on the water dimer, one might specify
vectors fragment h2o1.movecs h2o2.movecs
where h2o1.movecs contains the orbitals for the first fragment, and h2o2.movecs contains the orbitals for the second fragment.
A complete example of the input for a calculation on the water dimer using the fragment guess is as follows:
start dimer title "Water dimer SCF using fragment initial guess" geometry dimer O -0.595 1.165 -0.048 H 0.110 1.812 -0.170 H -1.452 1.598 -0.154 O 0.724 -1.284 0.034 H 0.175 -2.013 0.348 H 0.177 -0.480 0.010 end geometry h2o1 O -0.595 1.165 -0.048 H 0.110 1.812 -0.170 H -1.452 1.598 -0.154 end geometry h2o2 O 0.724 -1.284 0.034 H 0.175 -2.013 0.348 H 0.177 -0.480 0.010 end basis o library 3-21g h library 3-21g end set geometry h2o1 scf; vectors input atomic output h2o1.movecs; end task scf set geometry h2o2 scf; vectors input atomic output h2o2.movecs; end task scf set geometry dimer scf vectors input fragment h2o1.movecs h2o2.movecs \ output dimer.movecs end task scf
First, the geometry of the dimer and the two monomers are specified and given names. Then, after the basis specification, calculations are performed on the fragments by setting the geometry to the appropriate fragment (SET) and redirecting the output molecular orbitals to an appropriately named file. Note also that use of the atomic initial guess is forced, since the default initial guess is to use any existing MOs which would not be appropriate for the second fragment calculation. Finally, the dimer calculation is performed by specifying the dimer geometry, indicating use of the fragment guess, and redirecting the output MOs.
The following points are important in using the fragment initial guess:
- The fragment calculations must be in the same basis set as the full calculation.
- The order of atoms in the fragments and the order in which the fragment files are specified must be such that when the fragment basis sets are concatenated all the basis functions are in the same order as in the full system. This is readily accomplished by first generating the full geometry with atoms for each fragment contiguous, splitting this into numbered fragments and specifying the fragment MO files in the correct order on the VECTORS directive.
- The occupation of orbitals is preserved when they are merged from the fragments to the full molecule and the resulting occupation must match the requested occupation for the full molecule. E.g., a triplet ROHF calculation must be comprised of fragments that have a total of exactly two open-shell orbitals.
- Because of these restrictions, it is not possible to introduce additional atoms (or basis functions) into fragments for the purpose of cleanly breaking real bonds. However, it is possible, and highly recommended, to introduce additional point charges to simulate the presence of other fragments.
- MO vectors of partially occupied or strongly polarized systems are very sensitive to orientation. While it is possible to specify the same fragment MO vector file multiple times in the VECTORS directive, it is usually much better to do a separate calculation for each fragment.
- Linear dependencies which were present in a fragment calculation may be magnified in the full calculation. When this occurs, some of the fragment's highest virtual orbitals will not be copied to the full system, and a warning will be printed.
A more involved example is now presented. We wish to model the sextet state of Fe(III) complexed with water, imidazole and a heme with a net unit positive charge. The default atomic guess does not give the correct d5 occupation for the metal and also gives an incorrect state for the double anion of the heme. The following performs calculations on all of the fragments. Things to note are:
- The use of a dummy +2 charge in the initial guess on the heme which in part simulates the presence of the metal ion, and also automatically forces an additional two electrons to be added to the system (the default net charge being zero).
- The iron fragment calculation (charge +3, d5, sextet) will yield the correct open-shell occupation for the full system. If, instead, the d-orbitals were partially occupied (e.g., the doublet state) it would be useful to introduce dummy charges around the iron to model the ligand field and thereby lift the degeneracy to obtain the correct occupation.
- Cs symmetry is used for all of the calculations. It is not necessary that the same symmetry be used in all of the calculations, provided that the order and orientation of the atoms is preserved.
- The unset scf:* directive is used immediately before the calculation on the full system so that the default name for the output MO vector file can be used, rather than having to specify it explicitly.
start heme6a1 title "heme-H2O (6A1) from M.Dupuis" ############################################################ # Define the geometry of the full system and the fragments # ############################################################ geometry full-system symmetry cs H 0.438 -0.002 4.549 C 0.443 -0.001 3.457 C 0.451 -1.251 2.828 C 0.452 1.250 2.828 H 0.455 2.652 4.586 H 0.461 -2.649 4.586 N1 0.455 -1.461 1.441 N1 0.458 1.458 1.443 C 0.460 2.530 3.505 C 0.462 -2.530 3.506 C 0.478 2.844 1.249 C 0.478 3.510 2.534 C 0.478 -2.848 1.248 C 0.480 -3.513 2.536 C 0.484 3.480 0.000 C 0.485 -3.484 0.000 H 0.489 4.590 2.664 H 0.496 -4.592 2.669 H 0.498 4.573 0.000 H 0.503 -4.577 0.000 H -4.925 1.235 0.000 H -4.729 -1.338 0.000 C -3.987 0.685 0.000 N -3.930 -0.703 0.000 C -2.678 1.111 0.000 C -2.622 -1.076 0.000 H -2.284 2.126 0.000 H -2.277 -2.108 0.000 N -1.838 0.007 0.000 Fe 0.307 0.000 0.000 O 2.673 -0.009 0.000 H 3.238 -0.804 0.000 H 3.254 0.777 0.000 end geometry ring-only symmetry cs H 0.438 -0.002 4.549 C 0.443 -0.001 3.457 C 0.451 -1.251 2.828 C 0.452 1.250 2.828 H 0.455 2.652 4.586 H 0.461 -2.649 4.586 N1 0.455 -1.461 1.441 N1 0.458 1.458 1.443 C 0.460 2.530 3.505 C 0.462 -2.530 3.506 C 0.478 2.844 1.249 C 0.478 3.510 2.534 C 0.478 -2.848 1.248 C 0.480 -3.513 2.536 C 0.484 3.480 0.000 C 0.485 -3.484 0.000 H 0.489 4.590 2.664 H 0.496 -4.592 2.669 Bq 0.307 0.0 0.0 charge 2 # simulate the iron end geometry imid-only symmetry cs H 0.498 4.573 0.000 H 0.503 -4.577 0.000 H -4.925 1.235 0.000 H -4.729 -1.338 0.000 C -3.987 0.685 0.000 N -3.930 -0.703 0.000 C -2.678 1.111 0.000 C -2.622 -1.076 0.000 H -2.284 2.126 0.000 H -2.277 -2.108 0.000 N -1.838 0.007 0.000 end geometry fe-only symmetry cs Fe .307 0.000 0.000 end geometry water-only symmetry cs O 2.673 -0.009 0.000 H 3.238 -0.804 0.000 H 3.254 0.777 0.000 end ############################ # Basis set for everything # ############################ basis nosegment O library 6-31g* N library 6-31g* C library 6-31g* H library 6-31g* Fe library "Ahlrichs pVDZ" end ########################################################## # SCF on the fragments for initial guess for full system # ########################################################## scf; thresh 1e-2; end set geometry ring-only scf; vectors atomic swap 80 81 output ring.mo; end task scf set geometry water-only scf; vectors atomic output water.mo; end task scf set geometry imid-only scf; vectors atomic output imid.mo; end task scf charge 3 set geometry fe-only scf; sextet; vectors atomic output fe.mo; end task scf ########################## # SCF on the full system # ########################## unset scf:* # This restores the defaults charge 1 set geometry full-system scf sextet vectors fragment ring.mo imid.mo fe.mo water.mo maxiter 50 end task scf
Atomic guess orbitals with charged atoms
As noted above, the default guess vectors are based on superimposing the density matrices of the neutral atoms. If some atoms are significantly charged, this default guess may be improved upon by modifying the atomic densities. This is done by setting parameters that add fractional charges to the occupation of the valence atomic orbitals. Since the atomic SCF program does not have its own input block, the SET directive (SET) must be used to set these parameters.
The input specifies a list of tags (i.e., names of atoms in a geometry, see Geometry) and the charges to be added to those centers. Two parameters must be set as follows:
set atomscf:tags_z <string list_of_tags> set atomscf:z <real list_of_charges>
The array of strings atomscf:tags_z should be set to the list of tags, and the array atomscf:z should be set to the list of charges which must be real numbers (not integers). All atoms that have a tag specified in the list of tags will be assigned the corresponding charge from the list of charges.
For example, the following specifies that all oxygen atoms with tag O be assigned a charge of -1 and all iron atoms with tag Fe be assigned a charge of +2
set atomscf:z -1 2.0 set atomscf:tags_z O Fe
There are some limitations to this feature. It is not possible to add electrons to closed shell atoms, nor is it possible to remove all electrons from a given atom. Attempts to do so will cause the code to report an error, and it will not report further errors in the input for modifying the charge even when they are detected.
Finally, recall that the database is persistent (Data persistence) and that the modified settings will be used in subsequent atomic guess calculations unless the data is deleted from the database with the UNSET directive (UNSET).
Accuracy of initial guess
For SCF, the initial Fock-matrix construction from the atomic guess is performed to a default precision of 1e-7. However, other wavefunctions, notably DFT, use a lower precision. In charged, or diffuse basis sets, this precision may not be sufficient and could result in incorrect ordering of the initial orbitals. The accuracy may be increased with the following directive which should be inserted in the top-level of input (i.e., outside of the SCF input block) and before the TASK directive.
set tolguess 1e-7
THRESH -- convergence threshold
THRESH <real thresh default 1.0e-4>
This directive specifies the convergence threshold for the calculation. The convergence threshold is the norm of the orbital gradient, and has a default value in the code of 10 − 4.
The norm of the orbital gradient corresponds roughly to the precision available in the wavefunction, and the energy should be converged to approximately the square of this number. It should be noted, however, that the precision in the energy will not exceed that of the integral screening tolerance. This tolerance (Integral screening threshold) is automatically set from the convergence threshold, so that sufficient precision is usually available by default.
The default convergence threshold suffices for most SCF energy and geometry optimization calculations, providing about 6-8 decimal places in the energy, and about four significant figures in the density and energy derivative with respect to nuclear coordinates. However, greater precision may be required for calculations involving weakly interacting systems, floppy molecules, finite-difference of gradients to compute the Hessian, and for post-Hartree-Fock calculations. A threshold of 10 − 6 is adequate for most such purposes, and a threshold of 10 − 8 might be necessary for very high accuracy or very weak interactions. A threshold of 10 − 10 should be regarded as the best that can be attained in most circumstances.
MAXITER -- iteration limit
MAXITER <integer maxiter default 8>
The maximum number of iterations for the SCF calculation defaults to 20 for both ROHF/RHF and UHF calculations. For most molecules, this number of iterations is more than sufficient for the quadratically convergent SCF algorithm to obtain a solution converged to the default threshold (see Convergence threshold above). If the SCF program detects that the quadratically convergent algorithm is not efficient, then it will resort to a linearly convergent algorithm and increase the maximum number of iterations by 10.
Convergence may not be reached in the maximum number of iterations for many reasons, including input error (e.g., an incorrect geometry or a linearly dependent basis), a very low convergence threshold, a poor initial guess, or the fact that the system is intrinsically hard to converge due to the presence of many states with similar energies.
The following sets the maximum number of SCF iterations to 50:
maxiter 50
PROFILE -- performance profile
This directive allows the user to obtain timing and parallel execution information about the SCF module. It is specified by the simple keyword
This option can be helpful in understanding the computational performance of an SCF calculation. However, it can introduce a significant overhead on machines that have expensive timing routines, such as the SUN.
DIIS -- DIIS convergence
This directive allows the user to specify DIIS convergence rather than second-order convergence for the SCF calculation. The form of the directive is as follows:
The implementation of this option is currently fairly rudimentary. It does not have level-shifting and damping, and does not support open shells or UHF. It is provided on an "as is" basis, and should be used with caution.
When the DIIS directive is specified in the input, the user has the additional option of specifying the size of the subspace for the DIIS extrapolation. This is accomplished with the DIISBAS directive, which is of the form:
DIISBAS <integer diisbas default 5>
The default of 5 should be adequate for most applications, but may be increased if convergence is poor. On large systems, it may be necessary to specify a lower value for diisbas, to conserve memory.
DIRECT and SEMIDIRECT -- recomputation of integrals
In the context of SCF calculations direct means that all integrals are recomputed as required and none are stored. The other extreme are disk- or memory-resident (sometimes termed conventional) calculations in which all integrals are computed once and stored. Semi-direct calculations are between these two extremes with some integrals being precomputed and stored, and all other integrals being recomputed as necessary.
The default behavior of the SCF module is
- If enough memory is available, the integrals are computed once and are cached in memory.
- If there is not enough memory to store all the integrals at once, then 95% of the available disk space in the scratch directory (see File directories) is assumed to be available for this purpose, and as many integrals as possible are cached on disk (with no memory being used for caching). Some attempt is made to store the most expensive integrals in the cache.
- If there is not enough room in memory or on disk for all the integrals, then the ones that are not cached are recomputed in a semidirect fashion.
The integral file is deleted at the end of a calculation, so it is not possible to restart a semidirect calculation when the integrals are cached in memory or on disk. Many modern computer systems clear the fast scratch space at the end of each job, adding a further complication to the problem of restarting a parallel semidirect calculation.
A fully direct calculation (with recomputation of the integrals at each iteration) is forced by specifying the directive
Alternatively, the SEMIDIRECT directive can be used to control the default semidirect calculation by defining the amount of disk space and the cache memory size. The form of this directive is as follows:
SEMIDIRECT [filesize <integer filesize default disksize>] [memsize <integer memsize default available>] [filename <string filename default $file_prefix.aoints$>]
The keyword FILESIZE allows the user to specify the amount of disk space to be used per process for storing the integrals in 64-bit words. Similarly, the keyword MEMSIZE allows the user to specify the number of 64-bit words to be used per process for caching integrals in memory. (Note: If the amount of storage space specified by the entry for memsize is not available, the code cuts the value in half and checks again for available space. This process is repeated until the request is satisfied.)
By default, the integral files are placed into the scratch directory (see File directories). Specifying the keyword FILENAME overrides this default. The user-specified name entered in the string filename has the process number appended to it, so that each process has a distinct file but with a common base-name and directory. Therefore, it is not possible to use this keyword to specify different disks for different processes. The SCRATCH_DIR directive (see File directories) can be used for this purpose.
For example, to force full recomputation of all integrals:
Exactly the same result could be obtained by entering the directive:
semidirect filesize 0 memsize 0
To disable the use of memory for caching integrals and limit disk usage by each process to 100 megawords (MW):
semidirect memsize 0 filesize 100000000
The integral records are typically 32769 words long and any non-zero value for filesize or memsize should be enough to hold at least one record.
Integral File Size and Format for the SCF Module
The file format is rather complex, since it accommodates a variety of packing and compression options and the distribution of data. This section presents some information that may help the user understand the output, and illustrates how to use the output information to estimate file sizes.
If integrals are stored with a threshold of greater than 10 − 10, then the integrals are stored in a 32-bit fixed-point format (with appropriate treatment for large values to retain precision). If integrals are stored with a threshold less than 10 − 10, however, the values are stored in 64-bit floating-point format. If a replicated-data calculation is being run, then 8 bits are used for each basis function label, unless there are more than 256 functions, in which case 16 bits are used. If distributed data is being used, then the labels are always packed to 8 bits (the distributed blocks always being less than 256; labels are relative to the start of the block).
Thus, the number (W) of 64-bit words required to store N integrals, may be computed as
The actual number of words required can exceed this computed value by up to one percent, due to bookkeeping overhead, and because the file itself is organized into fixed-size records.
With at least the default print level, all semidirect (not direct) calculations will print out information about the integral file and the number of integrals computed. The form of this output is as follows:
Integral file = ./c6h6.aoints.0 Record size in doubles = 32769 No. of integs per rec = 32768 Max. records in memory = 3 Max. records in file = 5 No. of bits per label = 8 No. of bits per value = 32 #quartets = 2.0D+04 #integrals = 7.9D+05 direct = 63.6% cached = 36.4%
The file information above relates only to process 0. The line of information about the number of quartets, integrals, etc., is a sum over all processes.
When the integral file is closed, additional information of the following form is printed:
------------------------------------------------------------ EAF file 0: "./c6h6.aoints.0" size=262152 bytes ------------------------------------------------------------ write read awrite aread wait ----- ---- ------ ----- ---- calls: 6 12 0 0 0 data(b): 1.57e+06 3.15e+06 0.00e+00 0.00e+00 time(s): 1.09e-01 3.12e-02 0.00e+00 rate(mb/s): 1.44e+01 1.01e+02 ------------------------------------------------------------ Parallel integral file used 4 records with 0 large values
Again, the detailed file information relates just to process 0, but the final line indicates the total number of integral records stored by all processes.
This information may be used to optimize subsequent calculations, for instance by assigning more memory or disk space.
SCF Convergence Control Options
Note to users: It is desired that the SCF program converge reliably with the default options for a wide variety of molecules. In addition, it should be guaranteed to converge for any system, with sufficient iterations.
The SCF program uses a preconditioned conjugate gradient (PCG) method that is unconditionally convergent. Basically, a search direction is generated by multiplying the orbital gradient (the derivative of the energy with respect to the orbital rotations) by an approximation to the inverse of the level-shifted orbital Hessian. In the initial iterations (see Controlling the Newton-Raphson), an inexpensive one-electron approximation to the inverse orbital Hessian is used. Closer to convergence, the full orbital Hessian is used, which should provide quadratic convergence. For both the full or one-electron orbital Hessians, the inverse-Hessian matrix-vector product is formed iteratively. Subsequently, an approximate line search is performed along the new search direction. If the exact Hessian is being employed, then the line search should require a single step (of unity). Preconditioning with approximate Hessians may require additional steps, especially in the initial iterations. It is the (approximate) line search that provides the convergence guarantee. The iterations required to solve the linear equations are referred to as micro-iterations. A macro-iteration comprises both the iterative solution and a line search.
Level-shifting plays the same role in this algorithm as it does in the conventional iterative solution of the SCF equations. The approximate Hessian used for preconditioning should be positive definite. If this is not the case, then level-shifting by a positive constant (Δ) serves to make the preconditioning matrix positive definite, by adding Δ to all of its eigenvalues. The level-shifts employed for the RHF orbital Hessian should be approximately four times (only twice for UHF) the value that one would employ in a conventional SCF. Level-shifting is automatically enabled in the early iterations, and the default options suffice for most test cases.
So why do things go wrong and what can be done to fix convergence problems? Most problems encountered so far arise either poor initial guesses or from small or negative eigenvalues of the orbital Hessian. The atomic orbital guess is usually very good. However, in calculations on charged systems, especially with open shells, incorrect initial occupations may result. The SCF might then converge very slowly since very large orbital rotations might be required to achieve the correct occupation or move charge large distances in the molecule. Possible actions are
- Modify the atomic guess by assigning charges to the atoms known to carry substantial charges (Atomic guess)
- Examining an analysis of the initial orbitals (Printing) and then swapping them to attain the desired occupation (VECTORS).
- Converging the calculation in a minimal basis set, which is usually easier, and then projecting into a larger basis set (VECTORS).
- Using the fragment orbital initial guess (Fragment molecular orbitals).
Small or negative Hessian eigenvalues can occur even though the calculation seem to be close to convergence (as measured by the gradient norm, or the off-diagonal Fock matrix elements). Small eigenvalues will cause the iterative linear equation solver to converge slowly, resulting in an excessive number of micro-iterations. This makes the SCF expensive in terms of computation time, and it is possible to exceed the maximum number of iterations without achieving the accuracy required for quadratic convergence -- which causes more macro-iterations to be performed.
Two main options are available when a problem will not converge: Newton-Raphson can be disabled temporarily or permanently (see Controlling the Newton-Raphson), and level-shifting can be applied to the matrix (see Level-shifting). In some cases, both options may be necessary to achieve final convergence.
If there is reason to suspect a negative eigenvalue, the first course is to disable the Newton-Raphson iteration until the solution is closer to convergence. It may be necessary to disable it completely. At some point close to convergence, the Hessian will be positive definite, so disabling Newton-Raphson should yield a solution with approximately the same convergence rate as DIIS.
If temporarily disabling Newton-Raphson is not sufficient to achieve convergence, it may be necessary to disable it entirely and apply a small level-shift to the approximate Hessian. This should improve the convergence rate of the micro-iterations and stabilize the macro-iterations. The level-shifting will destroy exact quadratic convergence, but the optimization process is automatically adjusted to reflect this by enforcing conjugacy and reducing the accuracy to which the linear equations are solved. The net result of this is that the solution will do more macro-iterations, but each one should take less time than it would with the unshifted Hessian.
The following sections describe the directives needed to disable the Newton-Raphson iteration and specify level-shifting.
NR -- controlling the Newton-Raphson
NR <real nr_switch default 0.1>
The exact orbital Hessian is adopted as the preconditioner when the maximum element of the orbital gradient is below the value specified for nr_switch. The default value is 0.1, which means that Newton-Raphson will be disabled until the maximum value of the orbital gradient (twice the largest off-diagonal Fock matrix element) is less than 0.1. To disable the Newton-Raphson entirely, the value of nr_switch must be set to zero. The directive to accomplish this is as follows:
nr 0
LEVEL -- level-shifting the orbital Hessian
This directive allows the user to specify level-shifting to obtain a positive-definite preconditioning matrix for the SCF solution procedure. Separate level shifts can be set for the first-order convergent one-electron approximation to the Hessian used with the preconditioned conjugate gradient (PCG) method, and for the full Hessian used with the Newton-Raphson (NR) approach. It is also possible to change the level-shift automatically as the solution attains some specified accuracy. The form of the directive is as follows:
LEVEL [pcg <real initial default 20.0> \ [<real tol default 0.5> <real final default 0.0>]] \ [nr <real initial default 0.0> \ [<real tol default 0.0> <real final default 0.0>]]
This directive contains only two keywords: one for the PCG method and the other for the exact Hessian (Newton Raphson, or NR). Use of PCG or NR is determined by the input specified for nr_switch on the NR directive, Controlling the Newton-Raphson above.
Specifying the keyword pcg on the LEVEL directive allows the user to define the level shifting for the approximate (i.e., PCG) method. Specifying the keyword nr allows the user to define the level shifting for the exact Hessians. In both options, the initial level shift is defined by the value specified for the variable initial. Optionally, tol can be specified independently with each keyword to define the level of accuracy that must be attained in the solution before the level shifting is changed to the value specified by input in the real variable final. Level shifts and gradient thresholds are specified in atomic units.
For the PCG method (as specified using the keyword pcg), the defaults for this input are 20.0 for initial, 0.5 for tol, and 0.0 for final. This means that the approximate Hessian will be shifted by 20.0 until the maximum element of the gradient falls below 0.5, at which point the shift will be set to zero.
For the exact Hessian (as specified using the keyword nr), the defaults are all zero. The exact Hessian is usually not shifted since this destroys quadratic convergence. An example of an input directive that applies a shift of 0.2 to the exact Hessian is as follows:
level nr 0.2
To apply this shift to the exact Hessian only until the maximum element of the gradient falls below 0.005, the required input directive is as follows:
level nr 0.2 0.005 0
Note that in both of these examples, the parameters for the PCG method are at the default values. To obtain values different from the defaults, the keyword pcg must also be specified. For example, to specify the level shifting in the above example for the exact Hessian and non-default shifting for the PCG method, the directive would be something like the following:
level pcg 20 0.3 0.0 nr 0.2 0.005 0.0
This input will cause the PCG method to be level-shifted by 20.0 until the maximum element of the gradient falls below 0.3, then the shift will be zero. For the exact Hessian, the level shifting is initially 0.2, until the maximum element falls below 0.005, after which the shift is zero.
The default options correspond to
level pcg 20 0.5 0 nr 0 0 0
Orbital Localization
The SCF module includes an experimental implementation of orbital localization, including Foster-Boys and Pipek-Mezey which only works for closed-shell (RHF) wavefunctions. There is currently no input in the SCF block to control this so the SET directive (SET) must be used.
The directive
set scf:localize t
will separately localize the core, valence, and virtual orbital spaces using the Pipek-Mezey algorithm. If the additional directive
set scf:loctype FB
is included, then the Foster-boys algorithm is used. The partitioning of core-orbitals is performed using the atomic information described in Section 16.1.
In the next release, this functionality will be extended to included all wavefunctions using molecular orbitals.
Printing Information from the SCF Module
All output from the SCF module is controlled using the PRINT directive described in Print control. The following list describes the items from SCF that are currently under direct print control, along with the print level for each one.
|Print Level
|"atomic guess density"
|guess density matrix
|"atomic scf"
|details of atomic SCF
|"mo guess"
|brief info from mo guess
|"initial vectors"
|"intermediate vectors"
|"final vectors"
|"final vectors analysis"
|"initial vectors analysis"
|"intermediate evals"
|"final evals"
|integral screening info stats at completion
|"screening statistics"
|display stats after every Fock build
|detailed symmetry info
|detailed basis map info
|"vectors i/o"
|report vectors I/O
|convergence parameters
|info each iteration
|"mulliken ao"
|Mulliken population of basis functions
Hartree-Fock or SCF, MCSCF and MP2 Gradients
The input for this directive allows the user to adjust the print control for the SCF, UHF, ROHF, MCSCF and MP2 gradients. The form of the directive is as follows:
GRADIENTS [print || noprint] ... END
The complementary keyword pair print and noprint allows the user some additional control on the information that can be included in the print output from the SCF calculation. Currently, only a few items can be explicitly invoked via print control. These are as follows:
|Print Level
|calculation info
|geometry information
|basis set(s) used
|details of force components
|timing for each phase


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Tap in to your inner anglophile and enjoy the tastes of England on this side of the pond, right here in New York City.
Tea & Sympathy
108 Greenwich Ave. / Greenwich Village
Welsh rarebit, scotch egg, Shepherd's pie, the've got it all at Tea & Sympathy, a quaint little English restaurant right in the heart of Greenwich Village. It's been a neighborhood favorite for years. On the weekends, they serve an authentic full English breakfast (or shall we say Sunday dinner), a rare find in New York City. Any New Yorker who knows what bubble and squeak is will truly appreciate this find. They don't take reservations and the place is rather small, so get there early with your entire party. Can't get enough? Stop on by the adjoining market for some treats to take home.
Myers of Keswick
634 Hudson Street / West Village
This city is full of bodegas and generic supermarkets, but here's one you don't want to walk right past, Myers of Keswick--it's a traditional British supermarket where you can get your favorite English candies, chocolates, and even the ever popular cumberland sausages and sausage rolls that are staples to the Brits. Hankering for some pies, pasties, biscuits, Cadbury treats, or Digestives? They have it. Don't know what these are? Go on over anyway and get a lesson from the Brits.
Palm Court at the Plaza Hotel
5th Ave at Central Park South
Alice's Tea Cup
Various locations
Afternoon tea is an English tradition that even New Yorkers have adopted… okay, maybe not quite. However, if you wanted to enjoy tea time like the English do, complete with scones, clotted cream and finger sandwiches, you could! For a more formal tea time setting, check out Palm Court at the Plaza Hotel from 2pm to 5pm, as afternoon tea is served daily. There are four styles of afternoon tea, and we know at least one comes with champagne (Yeah, get that one!). For a less formal and more fun ambience, head on over to Alice's Tea Cup. While it's like stepping into an Alice in Wonderland dream at first glance, the endless selection of scones and teas will be what keeps you coming back.
Harney & Sons
433 Broome St. / Soho
Couldn't get enough tea at tea time? Can't make it to Fortnum & Mason in London? Well, we've got Harney & Sons for your fine tea needs. With over 250 varieties of teas, you could spend hours perusing and smelling the freshest selections. Their Historical Royal Palaces collection provides English tea blends for you to enjoy--they also make wonderful gifts. Stop by the Soho location for suggestions and tips from their expert staff.
Jones Wood Foundry
401 E. 76th St. / Upper East
Whether you're longing for your grandmother's shepherd's pie or want to be introduced to old English cuisine, Jones Wood Foundry is the place to go. Okay, maybe it's neither, and you just want a great neighborhood pub to hang out in with a nicely curated beer list and great ambiance, Jones Wood Foundry is still your place. Situated on the Upper East Side, where "cool hangs" are pretty sparse, it's a great spot for English comfort food and brews… and wine cocktails, if that strikes your fancy.
Get ready for a British invasion this Saturday! Catch "1st Look" with host Ali Fedotowsky after Saturday Night Live.


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Russian entrepreneur Yuri Milner is funding multimillion-dollar prizes for fundamental physics.
Russian entrepreneur Yuri Milner inaugurated his new prize program for fundamental physics today with a big bang: awards of $3 million each to nine of the world's best-known theorists.
Among the honorees are MIT's Alan Guth and Stanford's Andrei Linde, who developed the theory of cosmic inflation that currently stands as the most widely accepted model for the expansion of the universe.
In a Stanford news release, Linde said he could hardly believe what he was hearing when a telephone caller told him about the prize. At first, he told the caller that he'd have to think about accepting the money.
"Then I realized that I was making the most stupid joke of my life, and said that I would of course accept it," he said. "It's a huge prize. It's unbelievable."
The newly minted Fundamental Physics Prize is now the world's richest academic award, eclipsing the $1.2 million Nobel Prize as well as the $1.7 million Templeton Prize for science and spirituality.
Milner, 50, is himself a trained physicist who began his business career as an banking specialist and built up his fortune through a string of Internet investments, including stakes in Facebook, Zynga and Groupon. This year, Forbes estimated his net worth at $1 billion.
The $3 million Fundamental Physics Prize is to be awarded annually by the nonprofit Milner Foundation to recognize "transformative advances in the field." The $3 million prize may also be given at any time outside the formal nomination process "in exceptional cases," according to today's announcement from the foundation.
"I hope the new prize will bring long overdue recognition to the greatest minds working in the field of fundamental physics, and if this helps encourage young people to be inspired by science, I will be deeply gratified," Milner said in the announcement.
Promising junior researchers will be eligible for a different $100,000 annual award known as the New Horizons in Physics Prize.
To kick off the program, nine $3 million prizes were awarded today, and the nine recipients were invited to help select future honorees. In addition to Guth and Linde, the recipients include four string theorists at the Institute for Advanced Study at Princeton: Nima Arkani-Hamed, Juan Maldacena, Nathan Seiberg and Edward Witten. The three other honorees are Caltech's Alexei Kitaev, who focuses on quantum computing; Russian mathematician Maxim Kontsevich; and Indian string theorist Ashoke Sen.
Linde said he'd have to devote some serious study to his $3 million prize.
"For people who do not have a strong financial background, deciding what to do with this money is equally complicated as deciding what to do with the formation of the universe," he joked.
More about Milner:
Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.


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Tried some Kamut grain hot cereal! Better than oatmeal I LOVED IT! topped that off with some ground flaxseed, blackberries and candied pecans and a dab of MILK... Yum!!!
Also to accompany we had yummy bread I picked up from whole foods that you finish the baking process at home! Super healthy and yummy to boot!
I also tried our french press for the first time! WOW yummiest coffee I have ever had! It didn't need anything in it! Loved it black! Odly :)
Spent some time on the computer! Facebooking & Looking at my bloggs! and Miss Violet wanted to help too! :) she is so precious!
Jeff's morning is a bit different, he worked from home after breakfast.. which consisted of answering the blackberries! Ring Ring Ring!!!!! :) This is Jeff.... he is so cute! Just glad he can be home with me!
Now we are going to head out to Santa Monica to go look at apartments and explore!
Then out to Thousand Oaks! Laura's (Jeff's Sisters) Birthday is today! WOOO HOOO!


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Beautiful and very rare Double Neck Guitar in Weissenborn Style.
Top: Sitka Spruce
Back and sides: Mahogany
Fretboard: Rosewood
6.3mm and XLR line out system with built in pre-amp system
The pickup sys with two passive soundhole PU's and a 3-way toggle switch does its job very well. The passive pickups can be switched through a Pre-Amp System to reach a wider area of the instrument's frequencies.
All in all a magnificent super-rare to find Lap Slide Guitar.


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No-deal Brexit biggest near term risk to UK economy, IMF says
WASHINGTON DC - The International Monetary Fund believes the biggest risk to the UK economy in the near term is the country exiting the European Union without an agreement.
In asking if the IMF shared the view of the Bank of England, which the viewer said was that the impact of a no-deal Brexit would be worse than the global financial crisis, IMF representatives would not be drawn into that.
"I wouldn't comment on the Bank of England's assessment," Gerry Rice, Director of the Communication Department of the IMF said this week.
"Our views on the economic impact of Brexit I think have been well articulated and well covered, actually. We did a staff report on the UK several weeks ago, published mid-November, and it has our most updated scenarios."
"In summary, what we were saying in that staff report and Christine Lagarde has said this too, that all likely Brexit outcomes will entail costs for the UK economy by departing from the frictionless single market that exists today. And the higher the impediments, the higher the cost," Rice said.
"So, and again, we've said this for some time, an agreement that minimizes uncertainty and trade barriers will be the best to support growth. And we've also said I think I said here also a few weeks ago, that the hard Brexit or the no deal Brexit, leaving without a withdrawal agreement and a framework for the future relationship with the EU is the most significant near-term risk to the UK economy. So I'd characterize our position that way," the IMF official added.


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Truman's arson sentencing delayed
SYRACUSE - Sentencing for 54-year-old Jeffrey Truman which was scheduled for Thursday was moved to Jan. 29 in federal court in Syracuse.
After he was acquitted in a Madison County Court trial, Truman was found guilty in 2010 in federal jury trial of arson, two counts of mail fraud and using fire in the commission of a felony relating to the 2006 Stanton Paper Box factory fire on North Warner Street in Oneida.
The federal trial was presided over by District Judge David Hurd.
After the November 2010 federal trial ended, Hurd overturned the jury's verdict, acquitting Truman of all charges. Hurd's decision was then appealed by federal prosecutors in the Second Circuit Court of Appeals, which reinstated the jury's conviction.
The case was returned to Hurd in District Court July 25 for sentencing. At that time, Hurd recused himself from the case because, while he accepted the Circuit Court's decision, he believed Truman should be acquitted and might even be innocent.
Court officials said that the need to reschedule Truman's Jan. 17 sentencing was due to a court calendar conflict.
He last appeared in court in September before U.S. District Court Judge Norman Mordue for a detention hearing, a determination whether he would be jailed prior to sentencing or remain free on bail. Mordue ordered Truman to be placed in federal custody pending his sentencing.
Truman faces a minimum sentence of 15 years and up to 70 years in prison.
On Thursday, his attorney, Lisa Peebles of the Federal Public Defenders office said that at some point in the future, after the sentencing, she will file a motion to appeal his conviction.
In September, Peebles said she planned to seek a new trial based on new evidence which includes voicemail messages his son, Jeffrey Truman Jr., left for his father, saying that he lied when implicating his father during his trials. Federal Prosecutor Ed Broton argued that during the trials, the prosecution provided more than enough evidence that Truman is guilty.
The basis for an appeal is still in the works, Peebles said Thursday.
She noted that her office did not represent Truman during his trial, so she and her colleagues are, "still combing through records."
They have a few ideas for appeal angles, but could not comment on what will play out in the end, she added.