A virtual observatory for photoionized nebulae: the Mexican Million   Models database (3MdB)
  Photoionization models obtained with numerical codes are widely used to study the physics of the interstellar medium (Planetary Nebulae, H II regions, etc). Grid of models are performed to understand what are the effects of the different parameters used to describe the regions on the observables (mainly emission line intensities). Most of the time, only a small part of the computed results of such grids are published, and they are sometimes hard to obtain in a user-friendly format. We present here the Mexican Million Models dataBase (3MdB), an effort of resolving both of these issues in the form of a database of photoionization models, easily accessible throught the MySQL protocol, and containing a lot of usefull outputs from the models, such as the intensities of 178 emission lines, the ionic fractions of all the ions, etc. Some examples of the use of the 3MdB are also presented. 
Christophe Morisset, Gloria Delgado-Inglada and Nahiely Flores-Fajardo
astro-ph.GA