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Ground‐state and some excited states of Li 2 by the half‐projected Hartree–Fock method
Author(s) -
Fernándezserra P.,
Botella V.,
Smeyers Y. G.,
Galano A.,
DelgadoBarrio G.
Publication year - 1995
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.560540506
Subject(s) - wave function , singlet state , hartree–fock method , excited state , atomic physics , chemistry , ground state , triplet state , slater determinant , symmetry (geometry) , function (biology) , electronic structure , quantum mechanics , physics , computational chemistry , mathematics , atomic orbital , geometry , evolutionary biology , biology , electron
The half‐projected Hartree–Fock wave function ( HPHF ) is one of simplest models for introducing some electronic correlation effects. In this model, the wave function is built up with only two Slater determinants. This simple form suggests its application for the direct determination of singlet excited states. On the other hand, because the HPHF model does not mix singlet and triplet states with M s = 0, it can be used for determining independently singlet and triplet states without any mutual contamination. In the present work, we applied this model to determine nine electronic states of the lithium molecule; one of them exhibits even the same symmetry of the fundamental one. For this purpose, the 6‐311 G ( d ) basis was used. Potential energy curves were determined and some spectroscopic constants derived. The numerical results were compared with the available experimental data, as well as with other theoretical values. © 1995 John Wiley & Sons, Inc.