Electron propagator theory of bonding in saturated silicon chains

Abstract

Ab initio electron propagator calculations produce accurate electron binding energies and Feynman-Dyson amplitudes for oligosilanes as a function of bond angle and dihedral angle distortions. Ground state energies are also calculated for equilibrium and distorted structures. While the ground state energies are fairly insensitive to the distortions, changes in electron binding energies can be much larger. Examination of the Feynman-Dyson amplitudes leads to an electronic structure model that is based on phase relationships between bond orbital and antibond orbitals that are localized in SiSi bond regions. This model is successful in explaining the calculated shifts in electron binding energies and changes in polymer absorption spectra.