Some remarks about a generalized SCF coupling operator open shell theory

Abstract:

Li and He atomic systems are studied from the point of view of a general monoconfigurational Hartree-Fock coupling operator formalism. As a consequence, it is found that Lagrange multiplier hermitean conditions should be fulfilled in those electronic systems where hermiticity is not present by symmetry reasons, as in the Li ground state and the He first excited singlet. An additional condition is also needed when an excited state of the same symmetry and multiplicity of ground state should be calculated, as in He, allowing to apply the variational principle to the excited state energy functional. Without this condition, the monoconfigurational Hartree-Fock procedure will lead to unphysical energies. In semi-empirical calculations, however, the hermitean condition may be relaxed without provoking appreciable errors. The NO2 molecule is analysed within the CNDO framework to prove this possibility, which simplifies the treatment. © 1976.

Año de publicación:

1975

Keywords:

Fuente:

scopus