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Spline methods for multiconfiguration Hartree–Fock calculations
Author(s) -
Fischer Charlotte Froese,
Guo W.,
Shen Z.
Publication year - 1992
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.560420422
Subject(s) - orthogonality , spline (mechanical) , robustness (evolution) , hartree–fock method , grid , algorithm , quadratic growth , basis function , computer science , basis (linear algebra) , galerkin method , mathematics , mathematical analysis , physics , geometry , finite element method , quantum mechanics , biochemistry , gene , chemistry , thermodynamics
The earlier numerical multiconfiguration Hartree–Fock atomic structure package was not designed with high‐performance computers in mind. In this paper, some new algorithms based on spline–Galerkin methods are described that are appropriate for concurrent/vector architectures. The goal is to improve the level of numerical accuracy by several orders of magnitude using fewer basis functions than points in a numerical grid. Of critical importance is the robustness of the code: The most serious problems in the numerical implementation were associated with orthogonality constraints. In a spline basis approach, the orthogonality requirements can be integrated into quadratically convergent update procedures. These procedures are evaluated for a number of cases.