Premium
Ab initio quasirelativistic calculations on electronic transitions in ICl by the multireference many‐body perturbation theory
Author(s) -
Zaitsevskii Andréi,
Teichteil Christian
Publication year - 2002
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.10190
Subject(s) - ab initio , hamiltonian (control theory) , complete active space , multireference configuration interaction , chemistry , perturbation theory (quantum mechanics) , excited state , electronic correlation , electronic structure , ground state , atomic physics , ab initio quantum chemistry methods , relativistic quantum chemistry , configuration interaction , quantum mechanics , physics , basis set , computational chemistry , electron , density functional theory , molecule , mathematics , mathematical optimization
A quasirelativistic perturbative method of ab initio calculations on ground and excited molecular electronic states and transition properties within the relativistic effective core potential approximation is presented and discussed. The method is based on the construction of a state‐selective many‐electron effective Hamiltonian in the model space spanned by an appropriate set of Slater determinants by means of the second‐order many‐body multireference perturbation theory. The neglect of effective spin–orbit interactions outside of the model space allows the exploitation of relatively high nonrelativistic symmetry during the evaluation of perturbative corrections and therefore dramatic reduction of the cost of computations without any contraction of the model‐space functions. One‐electron transition properties are evaluated via the perturbative construction of spin‐free transition density matrices. Illustrative calculations on the X 0 + − A 1, B 0 + , and ( ii )1 transitions in the ICl molecule are reported. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002