Vibrational Linewidth of a Chemisorbed Polyatomic
{'Code': '03090004', 'Directorate': {'Abbreviation': 'MPS', 'LongName': 'Direct For Mathematical & Physical Scien'}, 'Division': {'Abbreviation': 'CHE', 'LongName': 'Division Of Chemistry'}}
{'SignBlockName': 'Richard Hilderbrandt', 'PO_EMAI': None, 'PO_PHON': None}
In this project in the Physical Chemistry Program, Buch will                    calculate the vibrational line shapes of molecules which are                    chemically absorbed on the surface of platinum.  The calculated                 line shapes for the ethylidyde molecule will then be compared                   with the detailed experimental results of Trenary et al.  This                  study will examine the influence of the high frequency                          adsorbate modes on the vibrational broadening mechanisms.  The                  results of the calculations will then be used to construct                      simplified models of a "system/bath" partition concept.                                                                                                         Line broadening mechanisms due to the interaction of the                        vibrational modes of the adsorbate with those of the solid will                 be studied.  An atomic level approach will be used in which IR                  line shapes are derived quantum-mechanically from the                           microscopic force field.  The focus will be on ordered                          overlayers of adsorbate which will take advantage of system                     periodicity to reduce the dimensionality of the problem.  Zero                  order motion of the system will be described by the adiabatic                   approximation, in which the low frequency substrate and                         adsorbate modes move in the average field of the high frequency                 adsorbate modes.  The resulting shifts in the low frequencies                   will be calculated for both the ground and excited states of                    the adsorbate, and used to evaluate the dephasing contribution                  to the linewidth.  The vibrational decay contribution will be                   calculated with the help of the golden rule.  The calculations                  will include no adjustable parameters; the data on the                          microscopic force field will be adopted from the literature.                    The markedly different widths and temperature dependencies of                   the three spectral lines measured experimentally by Trenary et                  al., will offer a unique opportunity to study mode specific                     effects in a chemisorbed polyatomic.  This will be the first                    quantum-mechanical atomic level study of IR line shapes of a                    polyatomic adsorbate, including both decay and dephasing                        contributions for a realistic microscopic potential.
{'FirstName': 'Victoria', 'LastName': 'Buch', 'PI_MID_INIT': None, 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'Victoria Buch', 'EmailAddress': None, 'NSF_ID': '000307248', 'StartDate': '06/01/1988', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'University of Illinois at Chicago', 'CityName': 'CHICAGO', 'ZipCode': '606124305', 'PhoneNumber': '3129962862', 'StreetAddress': '809 S MARSHFIELD AVE M/C 551', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'Illinois', 'StateCode': 'IL', 'CONGRESSDISTRICT': '07', 'CONGRESS_DISTRICT_ORG': 'IL07', 'ORG_UEI_NUM': 'W8XEAJDKMXH3', 'ORG_LGL_BUS_NAME': 'UNIVERSITY OF ILLINOIS', 'ORG_PRNT_UEI_NUM': None}
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{'Code': '195600', 'Text': 'STATISTICAL AND SIMULATIONS'}
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1988&All=true', 'xml': '8803436.xml'}