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Representations of the symmetric group generated by projected spin functions: A graphical approach

โœ Scribed by Sten Rettrup; Ruben Pauncz

Publisher
John Wiley and Sons
Year
1996
Tongue
English
Weight
507 KB
Volume
60
Category
Article
ISSN
0020-7608

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โœฆ Synopsis

The representation matrices generated by the projected spin functions have some very interesting properties. All the matrix elements are integers and they are quite sparse. A very efficient algorithm is presented for the calculation of these representation matrices based on a graphical approach and a new indexing scheme for representation of primitive spin functions is introduced. Test calculations show that the method is very fast and suited for calculations on vector computers.

๐Ÿ“œ SIMILAR VOLUMES

Symmetric group approach to relativistic
Symmetric group approach to relativistic CI. IV. Representations of one-electron spin operators and their products in a symmetric group-adapted basis of N-electron spin functions
โœ N. Flocke ๐Ÿ“‚ Article ๐Ÿ“… 1997 ๐Ÿ› John Wiley and Sons ๐ŸŒ English โš– 549 KB

A detailed study on representations of one-electron spin operators and of their products in an N-electron S S -adapted spin space is presented. Some conclusions relevant for their N evaluation and implementation in relativistic two-component SGAแŽCI calculations are derived.

Implementation of a general multireferen
Implementation of a general multireference configuration interaction procedure with analytic gradients in a semiempirical context using the graphical unitary group approach
โœ Axel Koslowski; Michael E. Beck; Walter Thiel ๐Ÿ“‚ Article ๐Ÿ“… 2003 ๐Ÿ› John Wiley and Sons ๐ŸŒ English โš– 156 KB

## Abstract The graphical unitary group approach has been applied in an efficient implementation of a general multireference configuration interaction (MRCI) method for use with small active molecular orbital spaces in a semiempirical framework. Gradients can be computed analytically for molecular