Is Everything Correct? The Formation Enthalpies Estimation and Data Revision of Nitrates and Perchlorates Salts

Abstract

Abstract Based on various calculation methods, the enthalpies of formation for a number of salts of nitric and perchloric acids were estimated. Relationships between the thermochemical characteristics of salts depending on various cations are considered. Calculations have been made and the efficiency of using a number of quantum-chemical methods in estimating the formation enthalpy of compounds in the gas phase has been analyzed. Based on a combination of quantum chemistry methods and Atom-Atom Potentials, the crystal structure of salts was simulated and the enthalpy of sublimation was estimated for subsequent use in calculations by the recently developed MICCM method. This method surpasses all the most commonly used calculation schemes in terms of accuracy in estimating the enthalpies of salt formation. Among the compounds considered, the calculations of the salts enthalpies of three amino-1,2,4-triazoles showed a significant discrepancy with the experimental data.