CALCULATION OF VIBRATIONAL WAVE-NUMBERS OF OCTAHEDRAL CLOSED-SHELL COMPLEXES USING SEMIEMPIRICAL METHODS OF QUANTUM-CHEMISTRY

The equilibrium geometries and the wavenumbers of all vibration modes were computed for closed-shell systems MX6(2-) (M = Ti, Zr, Hf, X = F, Cl). Quasi-relativistic parametrization of INDO/1 method was used for all studied. systems. Complexes containing Ti were studied by both th e nonrelativistic CNDO/2 and INDO/2 method, too. The results show reas onable agreement with the experimental data. The quasi-relativistic IN DO/1 method provides substantially better reproduction of experimental data than the nonrelativistic parametrizations.