Premium
Relativistic calculations of dissociation energies and related properties
Author(s) -
Pitzer Kenneth S.
Publication year - 1984
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.560250113
Subject(s) - excited state , bond dissociation energy , dissociation (chemistry) , atomic physics , relativistic quantum chemistry , ab initio , potential energy , configuration interaction , chemistry , ab initio quantum chemistry methods , ground state , bond length , molecule , spin (aerodynamics) , physics , quantum mechanics , thermodynamics
Methods of calculation of potential energy curves or surfaces, including dissociation energies, bond distances, and vibration frequencies, are discussed as well as recently obtained results for several molecules. The ab initio relativistic methods involve the derivation of “shape‐consistent” effective potentials from Dirac–Fock atomic calculations. These effective potentials are averaged and differenced with respect to spin with the differences, p 3/2 – p 1/2 , etc., yielding spin‐orbit operators. The molecular calculations are then set up in a familiar manner through the SCF stage using spin‐averaged effective potentials. The final stage is a configuration‐interaction calculation including the spin‐orbit terms as well as the electron repulsion terms. Calculations that have been made for several low‐lying excited states as well as the ground state for Au 2 , TlH, Tl 2 , Sn 2 , and Pb 2 are reviewed. Good agreement is obtained with spectroscopic data and a number of interesting predictions are made.