Calculation of Molecular Thermochemical Data and Their Availability in Databases

Abstract

Thermodynamic properties of molecules can be obtained by experiment, by statistical mechanics in conjunction with electronic structure theory and by empirical rules like group additivity. The latter two methods are briefly reviewed in this chapter. The overview of electronic structure methods is intended for readers less experienced in electronic structure theory and focuses on concepts without going into mathematical details. This is followed by a brief description of group additivity schemes; finally, an overview of databases listing reliable thermochemical data is given.

Validation of a Database of Formation Enthalpies and of Mid-Level Model Chemistries

“…The establishment of a database of accurate thermochemical data such as enthalpies of formation − is important for three reasons: Testing of new high-level quantum methods capable of dealing with a wide range of chemical compounds Using the well-validated data to expand the data set to species for which advanced quantum methods are currently too expensive from a computational viewpoint or for which experiment is much too difficult The application of the data to simulation and modeling of combustion phenomena and atmospheric and other chemistries. …”