A theoretical study of P4O10: vibrational analysis, infrared and Raman spectra

The normal mode frequencies and the corresponding vibrational assignments of tetraphosphorus decaoxide (P4O10) in tetrahedral (Td) symmetry are examined theoretically and experimentally. The Gaussian 98 set of quantum chemistry codes at the HF/6-311G*, MP2/6-311G*, and DFT/B3LYP/6-311G* levels of theory are used. By comparison to experimental normal mode frequencies deduced by Gilliam et al. [J. Phys. Chem. B 107 (2003) 2892], Chapman [Spectrochim. Acta A, 24 (1968) 1687], Beattie et al. [J. Chem. Soc. A (1970) 449], Konings et al. [J. Mol. Spectrosc. 152 (1992) 29] and the present work, correction factors for predominant vibrational motions are determined and compared. Normal modes were decomposed into five non-redundant motions (P-O stretch, P=O stretch, P-O-P bend, P-O-P wag, and P=O wag). Standard deviations found for the HF, MP2, and DFT corrected frequencies compared to experiment are 9, 5, and 4 cm(-1), respectively. Electron distribution for selected molecular orbitals is considered.