Two Component Calculations of Pt(2) With Relativistic Effective Core Potential Including Spin-Orbit Operator

Abstract

The Kramers restricted two-component ab initio calculations were performed for the eight lowest electronic states of Pt-2 using the relativistic effective core potential with the spin-orbit operator at the multireference first-order configuration interaction level of theory employing two-component molecular spinors as one-electron basis. The dominant role of the spin-orbit effects are mainly accounted for by using two-component spinors as one-electron wave function, and the importance of the dynamic and the nondynamic electron correlation effects are shown by employing configuration interaction and coupled cluster methods to obtain reliable spectroscopic data for this molecule. The two-component molecular spinors were generated from Kramers restricted Hartree-Fock calculations for the average configuration and used in the multireference Kramers restricted configuration interaction method to account for nondynamic correlation effect. Effect of dynamic correlations was investigated with the Kramers restricted coupled-cluster (KRCC) method. Spectroscopic constants calculated at the KRCC level are in good agreement with the most recent experimental values. (c) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 1975-1983, 2009