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143. LCAO-MO-SCF-CI: Program for Aromatic Systems
by G. W. Pukanic, D. R. Forshey, and J. D. Wegner, Duquesne University, Pittsburgh, Pennsylvania 15219 The program is applicable to conjugated neutral molecules containing no more than 16 p-electrons. A limited configuration interaction is superimposed on the SCF ground state. Excitations are considered between the two highest occupied and two lowest unoccupied molecular orbitals and involve either 1 electron (mode 1) jumps or both 1 and 2 selectively. Input consists of Cartesian coordinates of atoms; atomic valence states, effective nuclear charges, ionization potentials, and electron affinities; a set of initial eigenvectors obtained from a Hückel solution for the molecule; singlet and triplet wavefunctions and normalization constants; the empirical parameter H°; and a number of control cards and indices which are described in COMMENT cards in the beginning of the basic routine. This program requires the subroutines JACDAG (for diagonalizing a symmetric matrix) and MMULT (for multiplying matrices). The program calculates the molecular ionization potential, p-electron dipole moment, charge densities, and singlet and triplet excitation excitation energies and oscillator strengths. The first cited reference contains a complete program definition and flow chart, as well as a number of results obtained with the program. The calculations done by this program are described in Theoret. Chim. Acta (Bers.), 9, 38 (1967); ibid., 288 (1968); and ibid., 10, 240 (1968). FORTRAN IV Lines of Code: 1950 Recommended Citation: G. W. Pukanic et al., QCPE 11, 143 (1969). |