The a b i n i t i o model potential method. First series transition metal elements

Abstract

In the ab initio core model potential method the Coulomb and exchange core operators are represented accurately and the valence basis set is the only component of the method which is optimized (following the variational principle) in an atomic valence restricted Hartree–Fock (RHF) calculation. In this paper we present the nonrelativistic Ar‐like and Mg‐like core model potentials and valence Gaussian basis sets for the first series transition metal elements. The pilot RHF molecular calculations on ScO, MnO, CuO, and ScS show that freezing the 3s orbital is safe all along the transition series but the same is true for the 3p orbital only towards the end of the series. A good agreement exists between the all‐electron and model potential results if the same type of valence part of the basis set is used: 0.01 Å in R_e and 25 cm⁻¹ in ν̄_e.