Walter Thiel

A semiempirical model for the two-center repulsion integrals in the NDDO approximation

A self-consistent formalism is proposed for the two-center electron repulsion integrals in the NDDO approximation, based on their expansion in terms of multipole-multipole interactions and free from adjustable parameters.

CALCULATION OF PHOTOIONIZATION CROSS SECTIONS USING AB-INITIO WAVEFUNCTIONS AND THE PLANE WAVE APPROXIMATION

Abstract A method is outlined for the calculation of photoionization cross sections representing the initial state by a minimal basis set STO N G wavefunction and the final state by the plane wave approximation. Numerical results for several small molecules compare well with the band intensities in published ESCA spectra, and are superior to ESCA band intensities obtained from valence electron wavefunctions. For the UV region, ab-initio and valence electron calculations lead to comparable results.