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Kramers' restricted hartree—fock method for polyatomic molecules using ab initio relativistic effective core potentials with spin—orbit operators
Author(s) -
Lee Sang Yeon,
Lee Yoon Sup
Publication year - 1992
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.540130509
Subject(s) - polyatomic ion , ab initio , spinor , hartree–fock method , atomic physics , spin (aerodynamics) , molecular orbital , relativistic quantum chemistry , physics , molecule , open shell , wave function , symmetry (geometry) , chemistry , quantum mechanics , geometry , mathematics , thermodynamics
A two‐component Kramers' restricted Hartree–Fock method (KRHF) has been developed for the polyatomic molecules with closed shell configurations. The present KRHF program utilizes the relativistic effective core potentials with spin–orbit operators at the Hartree–Fock (HF) level and produces molecular spinors obeying the double group symmetry. The KRHF program enables the variational calculation of spin–orbit interactions at the HF level. KRHF calculations have been performed for the HX , X 2 , XY ( X , Y = I, Br), and CH 3 I molecules. It is demonstrated that the orbital energies from KRHF calculations are useful for the interpretation of spin‐orbit splittings in photoelectron spectra. In all molecules studied, bond lengths are only slightly expanded, harmonic vibrational frequencies are reduced, and bond energies are significantly decreased by the spin–orbit interactions.