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218. PROJR: Overlap Calculation between Two N-Electron
Antisymmetric Wave-functions
By Bruce R. Gilson, School of Chemistry, Wright Laboratory, Rutgers University, New Brunswick, New Jersey 08903 and Anthony J. Duben, Chemistry Department, St. Olaf College, Northfield, Minnesota 55057 This subroutine calculates the overlap between two N- electron wavefunctions. It also creates a list of the one-electron and two-electron integrals, and their weightings, between the two wavefunctions. This subroutine, then, is of use in creating a formula tape in a configuration interaction calculation. Subroutines WCAP (GTERM), KCAP (K,L,GTERM), and MCAP (I,J,K,L,GTERM) are called by PROJR. They are intended to be user supplied. These subroutines obtain the overlap, one-electron integrals, and two-electron integrals, respectively, and also the weighting of these integrals in the latter two cases. The K,L indices in the argument of KCAP and the I,J,K,L indices in the argument of MCAP are the orbitals which are present in the integral. GTERM is the weighting of the integral. In the driver package used here, the orbital indices in KCAP and MCAP are used to obtain the positions of the integrals in an upper triangular matrix read left to right along the rows. A detailed discussion of the algorithm is given by C. M. Reeves, Communications of the ACM, 9, 276 (1966). FORTRAN IV (IBM 360) Lines of Code: 371 Recommended Citation: B. R. Gilson and A. J. Duben, QCPE 11, 218 (1972). |