The well-tempered model core potentials for the main-group elements Li–Rn

Abstract.

The well-tempered model core potential (wtMCP) parameters and valence basis sets, based on the well-tempered basis set expansion, were developed for the main-group elements Li–Rn. For the s–block elements, the valence space comprises the ns valence shell and the outermost core (n−1)p shell. For the p-block elements, the ns and np shells together with the (n−1)d shell make up the valence space. Nonrelativistic wtMCPs were developed for all atoms. Scalar-relativistic wtMCPs were prepared for all atoms heavier than Ar by using the relativistic elimination of small components to obtain the reference and core orbitals. The new potentials were tested at the restricted Hartree–Fock, second-order Mø øller–Plesset perturbation theory and density functional theory with Becke’s three-parameter hybrid functional combined with Perdew’s 1991 gradient-corrected correlation functional levels for several diatomic molecules and the results were compared with those obtained from all-electron calculations and experimental values. Excellent agreement between the results was obtained.