ONE-CENTER INTEGRALS OF THE EXACT EFFECTIVE VALENCE SHELL HAMILTONIAN - EMPIRICAL-ANALYSIS FOR ATOMS
Additional Document Info
The exact effective valence shell Hamiltonian (Hv) which operates within a predetermined valence shell producing exact valence state energies and which can, in principle, be evaluated to arbitrary accuracy by purely systematic ab initio methods is analyzed. Specific application is made to the outer ns-np valence shell of C, N, O, F, Si, P, and S in order to determine the exact one-center integrals of Hv for comparison with recent ab initio calculations and with semiempirical theories which attempt to mimic Hv. The linearly independent matrix elements of the one-, two-, and three-electron effective interactions of Hv are obtained and it is shown that three-electron effective interactions are important. Some of these matrix elements are uniquely determined by atomic spectroscopic data. An optimal set of the remaining matrix elements is generated by a leastsquares fit. The relationship between the empirical one-center Hv matrix elements and the one-center, one- and two-electron parameters of semiempirical methods is given elsewhere. 1980, American Chemical Society. All rights reserved.