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Manuscript Title: Reduction of orbital sets. | ||

Authors: E. Francisco, L. Seijo, L. Pueyo | ||

Program title: OFMO | ||

Catalogue identifier: AATB_v1_0Distribution format: gz | ||

Journal reference: Comput. Phys. Commun. 43(1987)269 | ||

Programming language: Fortran. | ||

Computer: HP1000/45F. | ||

Operating system: RTE-6/VM. | ||

RAM: 36K words | ||

Word size: 16 | ||

Peripherals: disc. | ||

Keywords: Molecular physics, Integral, Basis set generation, Overlap's maximization, Lagrange multipliers. | ||

Classification: 16.10. | ||

Nature of problem:Given a set of atomic or molecular orbitals {psioi}, the program finds another orthonormal set, {psi i}, expressed in terms of a reduced basis {chi i}, that has maximum overlap with the given set. | ||

Solution method:The new set {Psi i}, is found by maximization of the overlap integrals <Psi i|Psi oi> with the orthogonality constraints <Psi i|Psi j> = Delta ij. The method of the undetermined Lagrange multipliers is used. Starting with a trial basis set {Chi}, the maximization is carried out with respect to the expansion coefficients connecting {Psi i} and {Chi i}. An analytical matrix equation is found for these coefficients. The nonlinear parameters of the basis {Chi i} are then optimized by means of an iterative process. | ||

Restrictions:The reference set {Psi oi} must be expressed in terms of Slater type orbitals(STO's) or Gaussian type orbitals(GTO's). When the {Psi oi} are made of STO's, the {Psi i} can be generated over STO's or GTO's. However, if the {Psi oi} are made of GTO's, the {Psi i} are generated over GTO's. | ||

Unusual features:None. | ||

Running time:53 s for the test run (with three cases). |

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