Program to implement MNDO/vs with analytic first-derivative computation and vibrational-spectrum calculation
Derivatives of the total energy with respect to the cartesian coordinates have been calculated with the ES computers for the MNDO/VS method. Standard atomic parameters enable one to calculate systems that include the following elements: H, Be, B, C, N, F, Al, Si, P, S, Cl, Sn, Br, I. It is possible to introduce the parameters for atoms in periods I-VI and to correct for hydrogen bonds formed by N, O, and F. Open-shell calculations have been performed by the unrestricted Hartree-Fock method with analytical derivative calculation or by Dewar's half-electron method from a standard scheme with numerical derivatives. The program envisages geometry optimization by the Davidon-Fletcher-Powell (DFP) method, Fletcher's method, and our modification of the Newton-Rafson method. It is possible to calculate the relative vibrational intensities in the dipole approximation; the derivatives of the dipole-moment components with respect to the cartesian coordinates are derived numerically from a three-point formula.
- OSTI ID:
- 6026426
- Journal Information:
- J. Struct. Chem. (Engl. Transl.); (United States), Journal Name: J. Struct. Chem. (Engl. Transl.); (United States) Vol. 28:5; ISSN JSTCA
- Country of Publication:
- United States
- Language:
- English
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71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALINE EARTH METALS
ALUMINIUM
ATOMIC MODELS
ATOMS
BERYLLIUM
BORON
BROMINE
CARBON
CHLORINE
COMPUTER CODES
COMPUTERIZED SIMULATION
EIGENVALUES
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY LEVELS
EXCITED STATES
FLUORINE
HALOGENS
HARTREE-FOCK METHOD
HYDROGEN
INFRARED SPECTRA
INTERMOLECULAR FORCES
IODINE
MATHEMATICAL MODELS
MATHEMATICS
MATRICES
MECHANICS
METALS
NITROGEN
NONMETALS
OPTIMIZATION
OXYGEN
PHOSPHORUS
QUANTUM MECHANICS
SEMIMETALS
SET THEORY
SILICON
SIMULATION
SPECTRA
SULFUR
TIN
VIBRATIONAL STATES