PNNL

Abstract

The heats of formation of CF3, its cation and anion, CF4, C2F4, and :CFCF3 have been calculated at high levels of ab initio molecular orbital theory. Geometries and frequencies were determined, in general, with second-order perturbation theory. Total energies based on coupled cluster calculations with perturbative triples were determined with basis sets up through augmented quadruple-Xi in quality and were subsequently extrapolated to the complete one-particle basis set limit, so as to further reduce the basis set truncation error. Due to its importance as a standard, CF4 was studied with even larger basis sets. Additional improvements in the atomization energy were achieved by applying corrections due to core/valence correlation, scalar relativistic, and atomic spin-orbit effects.