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Half-projected and projected Hartree-Fock calculations for singlet ground states. II. Lithium hydride

✍ Scribed by Yves G. Smeyers; G. Delgado-Barrio

Publisher
John Wiley and Sons
Year
1974
Tongue
English
Weight
536 KB
Volume
8
Category
Article
ISSN
0020-7608

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✦ Synopsis

Abstract

The half‐projected Hartree–Fock function (HPHF) for singlet states is defined as a linear combination of two Slater determinants which contains only spin eigenstates with even spin quantum numbers. The possible uses of such an approach for determining molecular properties are investigated computing the potential energy curve, binding energy, force constant, and dipole moment variation corresponding to the lithium hydride ground state. Full projected and restricted Hartree–Fock calculations (PHF and RHF) are performed simultaneously for comparison purposes. It is found that the HPHF model yields very satisfactory results, very close to those of the PHF scheme. Both models predict properly the molecular behavior as a function of nuclear separation, whereas the RHF one fails. A discussion is given in terms of configuration equivalents. It is concluded that the HPHF scheme seems to be useful for determining molecular properties specially in the case of large systems in which the more sophisticated methods are unmanageable.

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