Comparison ofabinitioand semiempirical pseudopotentials for Ca in calculations for CaO

摘要

Two recently reported pseudopotentials, anabinitioand a semiempirical one, both simulating the Arhyphen;like core of the Ca atom, are compared in calculations for CaO. While the former pseudopotential leads to a collapse of the molecule in theXthinsp;1Sgr;+ground state, such a collapse does not occur with the latter one. The reasons for this discrepancy are discussed and are attributed mainly to differences in the treatment of the higherlcomponents of the pseudopotentials.