Vibrational frequencies and structural determination of aluminum tetrahydroborate

The normal mode frequencies and corresponding vibrational assignments of aluminum tetrahydroborate in D 3 symmetry are examined theoretically using the gaussian 98 set of quantum chemistry codes. All normal modes were successfully assigned to one of seven types of motion (BH stretch, AlB stretch, BAlB bend, HBH bend, BH 4 wag, BH 4 rock, and BH 4 twist) predicted by a group theoretical analysis. By comparing the vibrational frequencies with infrared and Raman spectra available in the literature, a set of scaling factors is derived. Theoretical infrared intensities and Raman activities are reported.