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556. RPAC:Electronic Excitation Properties and
Nuclear Shielding in the Random Phase Approximation
System (Version 8.2)
by Thomas D. Bouman, Department of Chemistry, Southern Illinois University, Edwardsville, Illinois 62026 and Aage E. Hansen, Department of Physical Chemistry, H. C. írsted Institute, DK-2100 Copenhagen í, Denmark RPAC 8.2 is a major revision of QCPE 459. The program is a post-SCF package that computes electronic excitation energies, oscillator and rotatory strengths, transition densitiesand excitation charge rearrangements, and nuclear magnetic shielding tensors. In addition, it provides analyses in molecular structural terms and graphic output for these quantities. The following are among the features provided: * Excitation energies and intensities are calculated in the RPA method which gives the correct linear response of a Hartree-Fock ground state. STA, TDA, A+ methods are also available. No restrictions on the number of configurations in the calculation of the lowest excitations are set. * Changes in properties upon excitation may be computed in the same methods; and plots of orbitals, charge densities, transition densities, and charge rearrangement densities may be generated using the Jorgensen-Salem routines. * NMR shielding tensors are calculated in the LORG method, which is a CHF variant where the use of distributed origins greatly reduces basis-set errors. Standard CHF is also available. * Analyses of the electronic intensities and NMR shieldings include decomposition into bond and bond- bond terms. Rotatory strengths may be analyzed into terms mimicking Kirkwood's theory of optical activity. * NMR calculations and the various analyses require localized orbitals. Foster-Boys localization is provided for occupied orbitals, with optional localization block-by-block; virtual orbitals may be localized by maximizing transition moments involving localized occupied orbitals. * Output from a closed-shell Hartree-Fock calculation is required.Detailed interfacing instructions with an SCF package are given, and a sample interface to Gaussian 80 is provided. * Input options are selected by keyword. * The program system has been designed for easy portability to non-IBM machines. * Graphics routines download files to a PC for generating actual plotter commands. Calcomp and HP- GL interfaces are provided. _________ References: Aa. E. Hansen and T. D. Bouman, J. Am. Chem. Soc., 107, 4828 (1985). Aa. E. Hansen and T. D. Bouman, J. Chem. Phys., 82, 5035 (1985). T. D. Bouman, Aa. E. Hansen, B. Voigt and S. Rettrup, Int. J. Quantum Chem., 23, 595 (1983). Aa. E. Hansen and T. D. Bouman, Adv. Chem. Phys., 44, 545 (1980). __________ NOTE:This system is distributed on an UNLABELED multifile tape in BLKSIZE = 4000. FORTRAN 77 (IBM VS FORTRAN and MICROSOFT FORTRAN) Lines of Code: 25,400 |