Application of Accurate MP2 Energies for Closed-Shell Atoms in Examinations of Density Functionals for 3d~10 Electron Ions

摘要

Arguments are presented that accurate second-order M011er-Plesset(MP2)energies,evaluated in calculations involving extensive radial and angular basis sets,followed by careful angular extrapolations(referred to as MP2/CA energies),provide reliable approximations to the correlation energies for the ground states of closed-shell atomic systems.MP2/CA energies are calculated for the members of the Cu~+ isoelectronic series(Cu~+,Zn~2+,Ge~4+,and Kr~8+),which belong to the simplest atomic system containing the 3d~10 configuration.The most accurate ab initio correlation energies for a 28-electron isoelectronic series are reported.To exemplify the applicability of the total nonrelativistic energies,obtained as a sum of these energies and accurate Hartree-Fock energies,in examinations of density functionals,density functional theory energies are calculated for various functionals and basis sets and compared with their MP2/CA counterparts.An evaluation of the performance of these functionals is presented.The impact of the limited basis set size on the energy results is estimated.