HARTREE–FOCK WAVE FUNCTIONS FOR EXCITED STATES: THE 2 1S STATE OF HELIUM
- 1 October 1965
- journal article
- Published by Canadian Science Publishing in Canadian Journal of Physics
- Vol. 43 (10) , 1867-1881
- https://doi.org/10.1139/p65-178
Abstract
Hartree–Fock wave functions for the first-excited singlet states of several members of the helium isoelectronic sequence have been calculated. It is shown that unphysically low energies result if the excited-state function is not constrained to be orthogonal to the ground-state eigenfunction, and the excited-state orbitals are chosen orthogonal.If the excited-state orbitals are not chosen orthogonal, the effect of the overall constraint is small, raising the total energy very slightly; however, the effect of imposing both constraints simultaneously is appreciable. It is concluded that the most satisfactory approximation involves nonorthogonal excited-state orbitals, together with an overall orthogonality constraint towards the ground state.Keywords
This publication has 3 references indexed in Scilit:
- Hartree-Fock and Correlation Energies for 1s2s3S and1S States of Helium-like IonsProceedings of the Physical Society, 1962
- The Hartree Energies of the Helium SequenceProceedings of the Physical Society, 1961
- Analytical Self-Consistent Field Functions for the Atomic Configurations , , andReviews of Modern Physics, 1960