THEORETICAL-STUDY OF THE VIBRATIONAL-SPECTRA OF THE TRANSITION-METAL CARBONYL HYDRIDES HM(CO)(5) (M=MN, RE), H(2)M(CO)(4) (M=FE, RU, OS), AND HM(CO)(4) (M=CO, RH, IR)

The geometries of the title compounds have been optimized at the level s of restricted Hartree-Fock (RHF) theory, second-order Moller-Plesset perturbation theory, and gradient-corrected density functional theory (DFT) using all-electron and effective core potential wave functions in conjunction with polarized double- and triple-zeta basis sets. The harmonic force fields have been determined from RHF and DFT calculatio ns. The DFT results are generally in very good agreement with the avai lable experimental data. The computed frequencies are accurate enough to be of predictive value, especially when correcting for small system atic errors. Several new assignments of bands in the observed vibratio nal spectra are proposed. Infrared intensities, dipole moments, and ch arge distributions are also discussed. (C) 1996 American Institute of Physics.