A comparison of multi-configuration Hartree-Fock and configuration interaction results for the1D series of Mg

Abstract

Two-configuration Hartree-Fock results are reported for the 3s3d, 3s4d, and 3s5d ¹D states of magnesium where the interacting configurations are 3snd and 3p². These are compared with configuration interaction results where the basis set of radial functions includes the single- configuration Hartree-Fock functions for 3s3d and 3p^{2 1}D, and additional ones with the property that the interaction of either 3s3d or 3p² with certain singly substituted states is zero. The two sets of results are compared. The configuration interaction results are found to be less accurate owing to the diffuseness of the nd basis set. In both cases the interaction of 3p² with the 3s epsilon d continuum is important.