AB-INITIO CALCULATIONS OF ENERGIES OF SINGLET-TRIPLET EXCITATIONS IN DIATOMIC AND TRIATOMIC B, C, AL, AND SI HYDRIDES AND HALIDES

The energies of singlet-tripler excitations in two-and triatomic B, C, Al, and Si hydrides and halides are calculated within the unrestricte d Hartree-Fock-Roothaan (UHF) method with allowance for the correlatio n energy by the Moller-Plesset theory of the second and fourth orders (MP2 and MP4), The calculated energies are used to predict the ratio b etween activation barriers to redox reactions of the MXk-2 + X-2-->MXk type, where M = B, C, Al and Si and X = H, F, and Cl.