Thermochemical plots using JCZS2i piece-wise curve fits.

Abstract

This report presents plots of specific heat, enthalpy, entropy, and Gibbs free energy for 1439 species in the JCZS2i database. Included in this set of species are 496 condensed-phase species and 943 gas-phase species. The gas phase species contain 80 anions and 112 cations for a total of 192 ions. The JCZS2i database is used in conjunction with the TIGER thermochemical code to predict thermodynamic states from ambient conditions to high temperatures and pressures. Predictions from the TIGER code using the JCZS2i database can be used in shock physics codes where temperatures may be as high as 20,000 K and ions may be present. Such high temperatures were not considered in the original JCZS database, and extrapolations made for these temperatures were unrealistic. For example, specific heat would sometimes go negative at high temperatures which fails the definition of specific heat. The JCZS2i database is a new version of the JCZS database that is being created to address these inaccuracies. The purpose of the current report is to visualize the high temperature extrapolations to insure that the specific heat, enthalpy, entropy, and Gibbs free energy predictions are reasonable up to 20,000 K.