The evaluation of the one-centre integrals in the semi-empirical molecular orbital theory

An expression is given which fairly accurately provides valence-state energies. It is shown that one can formally attribute the meaning of the one-centre integrals to the coefficients in such an expression. In this way one also obtains the criteria of Pariser and Parr. Moreover, if one introduces such semi-empirical integrals in the expression which gives the vertical ionization potentials and electron affinities, one obtains the corresponding experimental values. On the basis of these facts usage of such semi-empirical integrals in the M.O.-L.C.A.O. theory is proposed. A discussion of the advantages and the limitations of its application is made.