On the calculation of multiplet energies by the hartree-fock-slater method

It is shown that a consistent application of the p1/3 approximation of the Hartree-Fock-Slater method requires the use of one specific procedure, the sum method, for the calculation of the energy Es1of singlet excited states of closed shell molecules. Further, Es1is found to be in reasonable agreement with experiment for a number of molecules, contrary to the energy Es2obtained according to another method discussed in the literature. The calculation of other multiplet splittings than singlet-triplet in the Hartree-Fock-Slater method is also considered.

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