The Kramers' restricted complete active space self-consistent-field method for two-component molecular spinors and relativistic effective core potentials including spin-orbit interactions

摘要

The Kramers' restricted complete active space self-consistent-field (KR-CASSCF)method based upon two-component molecular spinors and relativistic effective core potentials including spinorbit interactions is implemented,employing the two-step approach,in which teh expansion coefficients of configurations and molecular spinors are determined alternately.The present approach alows the influence of spin-orbit interactions to be taken into account in the optimizatio of one-electron wave function space.Test calculatins were performed for the Hg atom,Au~- anion,and Tl~+ cation wiht the closed-shell electronic configuration,the ground state potential energy curves of homo-nuclear diatomic molecules,As_2,Sb_2,and Bi_2,over a wide range of inter-nuclear distances,and the bond fission of a polyatomic molecule Ch_3I.the results show that the KR-CASSCF method properly describes the sissociation of molecules for the fine-structure states.It is alsoevident that molecular properties are affected by optimized spinors for systems containing heavy atoms such as Bi_2 and CH_3I at the CASSCF level of theory.