Bruce J. Rosenberg

Abinitio vertical spectra and linear bent correlation diagrams for the valence states of CO2 and its singly charged ions

Correlated and uncorrelated ab initio vertical spectra are reported for the valence states of CO2, CO2+, and CO2−. Calculations with polarized and unpolarized basis sets are compared at each level. Ground state quadrupole moments are computed. Linear molecule to bent molecule SCF correlation diagrams are also reported.

Theoretical studies of atmospheric molecules: SCF and correlated potential surface results for the X 2B1 and ? 2B2 states of H2O+

SCF and MCSCF/CI calculations were carried out on the X 2B1 and ? 2B2 states of H2O+. Vibrational analyses based on second order perturbation theory were also performed. Computed equilibrium geometries, force constants, and low‐lying vibrational frequencies for both the SCF and MCSCF/CI surfaces are reported.

Theoretical studies of atmospheric molecules: SCF and correlated energy levels for the NO2, NO 2 + and NO 2 ? systems

SCF and MC-SCF/CI calculations were carried out on the low-lying electronic states of NO2, NO2+ and NO2−, using a double-zeta quality basis set of contracted Gaussian functions. The calculations were performed primarily at the equilibrium geometry (RNO = 2.25 ao, θONO=134 °) of theX2A1 state of NO2. SCF calculations on NO2+ in a linear conformation were also performed. Results are presented and compared with experiment and other calculations.

Application of perturbation theory in large configuration interaction calculations

Abstract Rayleigh-Schrodinger perturbation theory has been applied through fifth order in the energy, to the problem of estimating the roots of the secular equation in large configuration interaction calculations. The NO 2 + , O 3 and H 2 O molecules are used as test cases, with accuracy as good as 0.01 eV, with appropriate choice of zero order problem.