Any chemical species that appears in a problem must have thermodynamic data associated with it. The format required for these data is described in this chapter. Also Standard State Enthalpies and Entropies at 298 K includes a discussion and listing of the standard-state enthalpies and entropies for the data contained in the therm.dat database file, which is included with every Ansys Chemkin installation.

Thermodynamic data may be extracted from a database file (for example, therm.dat) and/or read from the Gas-phase Kinetics or Surface Kinetics input file. If all of the thermodynamic data are to be extracted from a database file, then no thermodynamic data input in the Gas-phase Kinetics or Surface Kinetics input file is required. However, if you want to override information in the database or to provide data on species not in the database, then thermodynamic data are needed in the Gas-phase Kinetics or Surface Kinetics input file. In any case, the format for the information is the same.