With this grant in the Theoretical and Computational Chemistry Program of the Chemistry Division Professor Ortiz will apply electron propagator theory to the computation of the electronic structure of small molecules. The computations will aid in the interpretation of the electronic structure and bonding of many interesting atomic and molecular systems. Electron propagator theory provides a correlated one-electron picture of bonding through accurate calculations of electron binding energies and Feynman-Dyson amplitudes. Improvements to existing codes will concentrate on propagator renormalizations. Reference state averages will be improved with certain infinite order corrections by employing amplitudes from coupled cluster singles and doubles calculations. Diagonalization of the superoperator Hamiltonian matrix with an algorithm based on inverse iterations will result in operator manifold renormalizations. Full two-electron transformations will facilitate calculations on large molecules and interface with other codes. The dependence of one-electron states and energies on chain length and on local conformations will be explored for polysilane oligomers. Relationships between bond energies and ionization energies will be studied for half-sandwhich organometallics. Nonresonant emissions in triatomic radicals will be considered through calculations of ground and excited state potential energy surfaces. Explanations for the stabilities of various double Rydberg anions will be sought through one electron pictures.
