Media type: E-Article Title: Valence bond revisited. Approximate second-order perturbation energies Contributor: Montgomery, H.E.; Knight, Robert E. imprint: Elsevier BV, 1974 Published in: Chemical Physics Letters Language: English DOI: 10.1016/0009-2614(74)90210-3 ISSN: 0009-2614 Keywords: Physical and Theoretical Chemistry ; General Physics and Astronomy Origination: Footnote: