Loop-driven graphical unitary group approach multiconfiguration self-consistent-field method with applications to water, ozone, and cyclopropenyl radical

Technical Report · Tue Dec 01 04:00:00 EST 1981

OSTI ID:5608660

Laidig, W D

A multiconfiguration self-consistent-field (MCSCF) method based on the loop-driven graphical unitary group approach (LDGUGA) has been developed that combines the best features of the LDGUGA configuration interaction (CI) procedure with the ability to optimize the molecular orbitals. In contrast to traditional MCSCF procedures which are restricted to small configuration sets, our method can handle very large numbers of configurations. Unlike other large configuration list MCSCF procedures, however, the CI expansion is not restricted to being of a particular form (such as in the CASSCF method). The formalism we adopt is an iterative two-step process, that is, during each iteration the CI coefficients are optimized for a fixed guess at the orbital expansion coefficients and then improved orbitals are computed using these CI coefficients.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5608660
• Report Number(s): LBL-13917; ON: DE82010889
• Country of Publication: United States
• Language: English

Related Subjects

640305* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Theory-- (-1987)
74 ATOMIC AND MOLECULAR PHYSICS
ALGORITHMS
ARYL RADICALS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXCITED STATES
FUNCTIONS
GROUND STATES
HYDROGEN COMPOUNDS
MATHEMATICAL LOGIC
MATRIX ELEMENTS
MOLECULAR ORBITAL METHOD
MOLECULAR STRUCTURE
OXYGEN COMPOUNDS
OZONE
RADICALS
SELF-CONSISTENT FIELD
SYMMETRY BREAKING
WATER
WAVE FUNCTIONS