Relativistic dsp-model core potentials for main group elements in the fourth, fifth and sixth row and their applications

We have developed advanced relativistic model core potentials (dsp-MCPs) for the fourth (Ga-Kr), fifth (In-Xe) and sixth-row (Tl-Rn) main-group elements, where the outermost core (n - 1)d electrons were treated explicitly as well as the ns and np valence electrons. The remaining core electrons were replaced by dsp-MCPs. The major relativistic effects were incorporated into the dsp-MCPs at the level of Cowan and Griffin's quasi-relativistic Hartree-Fock method. We applied dsp-MCPs to calculate spectroscopic constants for the ground states of the rare-gas diatomic molecules Kr-2 and Xe-2. The results obtained by coupled pair approximation using atomic natural orbital (ANO) basis sets, in which the correlation of inner (n - 1)d electrons was included as well as those of the valence ns and np electrons, give excellent agreement with experimental values. (C) 1998 Elsevier Science B.V. All rights reserved.