Rule-based trial wave functions for generalized valence bond theory

Journal Article · Thu Dec 22 04:00:00 EST 1994 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100102a012· OSTI ID:6650392

Langlois, J M; Yamasaki, Terumasa; Muller, R P; Goddard, III, W A ^[1]

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1. California Institute of Technology, Pasadena, CA (United States)

We present a general method suitable for automatic generation of trial wave functions for generalized valence bond (GVB) descriptions of large molecules. This method uses pseudo-Hartree-Fock (P-HF) molecular orbitals formed from HF atomic orbitals but without Fock matrix diagonalization. The occupied P-HF orbitals are projected onto atomic basis functions to obtain GVB first natural orbitals, and the unoccupied HF orbitals are projected to obtain GVB second natural orbitals. This method (denoted GVB-INIT) is fast because no HF wave functions need be calculated and because the localization is piecewise atomic. In conjunction with the recently developed GVB-DIIS method for converging GVB wave functions and the new pseudospectral programs (PS-GVB) for the Fock matrix elements, GVB-INIT makes calculation of highly correlated GVB wave functions quite practical. The efficacy of GVB-INIT is illustrated by application to several cases including GVB wave functions with up to 26 correlated pairs. 17 refs., 7 tabs.

• OSTI ID: 6650392
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 98:51; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
99 GENERAL AND MISCELLANEOUS
990200 -- Mathematics & Computers
CALCULATION METHODS
CHEMICAL BONDS
COMPILED DATA
DATA
EIGENVALUES
FUNCTIONS
HARTREE-FOCK METHOD
INFORMATION
MATHEMATICAL MODELS
NUMERICAL DATA
VALENCE
WAVE FUNCTIONS