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The optimum projection technique in many‐electron treatments
Author(s) -
Cantu A. A.,
HartDavis A.
Publication year - 1971
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.560050305
Subject(s) - atomic orbital , antisymmetric relation , projection (relational algebra) , eigenfunction , space (punctuation) , function (biology) , slater determinant , spin (aerodynamics) , chemistry , physics , quantum mechanics , electron , atomic physics , computational chemistry , mathematics , mathematical physics , thermodynamics , algorithm , computer science , eigenvalues and eigenvectors , evolutionary biology , biology , operating system
The optimum projection technique is the determination of the best function in the space spanned by a set off f (N, S) linearly independent antisymmetric space‐spin eigenfunctions of S 2 obtainable from a spatial function made of a product of N ‐independent orbitals. This is formulated in the spin‐free framework. We consider several sets of predetermined orbitals for the lithium 2 S state. Both the energy and spin‐density are determined for each optimum projected function. The behavior of certain results is explained in terms of the “closeness” of the l s and l s ′ split‐shell core orbitals.