An Automatic Procedure for the Symmetry Blocking of SemiEmpirical Hamiltonians
Abstract
We present a procedure for the blockdiagonalisation of a Fock matrix which does not require explicit details of the point group of the molecule concerned. The method consists of two parts: (a) the trial eigenvectors determined at the start of a semiempirical calculation are analysed to give an initial set of symmetryadapted functions; and (b) these symmetryadapted functions are modified by testing for a correct blocking in the initial diagonalisation of the Fock matrix. Only minor modifications to existing semiempirical programs are needed for the inclusion of the routines to perform the algorithm.
 Publication:

Journal of Computational Physics
 Pub Date:
 February 1982
 DOI:
 10.1016/00219991(82)901206
 Bibcode:
 1982JCoPh..45..255H