Implementation of pseudopotential in the G3 theory for molecules containing first-, second-, and non-transition third-row atoms

摘要

Compact effective pseudopotential (CEP) is adapted in the G3 theory providing a theoretical alternativenreferred to as G3CEP for calculations involving the first-, second-, and non-transition third-rownelements. These modifications tried to preserve as much as possible the original characteristics ofnG3. G3CEP was used in the study of 247 enthalpies of formation, 22 atomization energies, 104 ionizationnpotentials, 63 electron affinities, and 10 proton affinities, resulting in the calculation of 446nspecies for the first-, second-, and third-row atoms. The final average total absolute deviation was ofn1.29 kcal mol−1 against 1.16 kcal mol−1 from all-electron G3 for the same calculations. The CPUntime has been reduced by 7% to 56%, depending on the size of the molecules and the type of atomsnconsidered.