SOME REMARKS ON THE PARISER-PARR-POPLE METHOD.
Scientific rept. no. 12,
UPPSALA UNIV (SWEDEN)
Pagination or Media Count:
Basic assumptions which characterize the Pariser-ParrPople method of computing molecular electronic wave functions are critically examined. By restricted variational calculation of the valence state of carbon and nitrogen atoms and ions, it is demonstrated that the usual methods of evaluation of one-centre Coulomb integrals and atomic core energies are rather good. A semi-theoretical means of estimating the core resonance integral is proposed and shown to 1 19r agreement with the empirical values for C-C, O-O, C-N, and C-O bonds. Author