Abstract
The CCCBDB is a collection of experimental and theoretical thermochemical properties for 580 neutral gas-phase species. The goal of the database/website is to provide a benchmark set of molecules and reactions for the evaluation of ab initio computational methods and to allow the comparison between different ab initio computational methods and experiment for the prediction of thermochemical properties.The format of the site is to ask for the property of interest, then the molecule or molecules of interest, and then the level of theory. The experimental and computational data is available as is (heats of formation in kJ/mol, computed energies in hartrees, lists of vibrational frequencies) and the same data can also be used in comparisons. For example the reaction energy of a user-specified reaction can be listed for different levels of theory.So far the computational data is limited to 14 methods using the 6-31G* basis set, semiempirical levels (AM1 and PM3), and some G2 calculations. Work on other basis sets is in progress and data is continually added as calculations finish.The database is accessible at:
http://srdata.nist.gov/cccbdb/