The infrared and Raman spectra for'phosphoryl chloride, thiophosphoryl chloride, and phosphoryl fluoride were collected and examined for the mosfprobable values for the wave numbers, intensities, and depolarization factors. The data are as follows: The Raman displacements t:,.u in em-I, the relative intensities I, and the depolarization factors p are for POCLs: t:..u(1)p= 192.85 (8) 0.83, 267.39 (6) 0.64, 337.44 (7) 0.81, 486.24 (10) 0.05,581.2 (3) 6/7, and 1289.9 (5) 0.04; for PSCIa: 172 (5) 6/7,247 (7) 6/7,247 (calculated) 430 (10) 0.1, 538 (1) 6/7, and 753 (1) P; and for POFs: 337 (w) 6/7, 476 (m) 6/7, 483 (from infrared) P,875 (s) 0.05,982 (vw) 6/7, and 1395 (m) 0.1. As for the infrared spectral data, those of G. Cilento et al., were used for PSCIa, and those of Gutowsky and Liehr were used for POFs. No published infrared spectral data were found for POCIa. Also normal coordinate treatments were conducted for POCIa, PSCIa, POFs, and PSFa on the basis of a model having Cs. symmetry. The normal coordinate treatments gave the listed wave numbers as fundamentals and lend support for the 247 cm-I band for PSCIa and 483 cm-I band (observed in the infrared and assigned'as fundamental by Gutowsky and Liehr) for POFs as the missing Raman bands. Moreover, the Fimatrix elements obtained for these molecules were determined in such a manner that those potential constants;for the PCIa group had nearly the same values in both PO CIa and PSCIa, those for the PFa group had"nearly;the same values in both POF a and PSFs, the one for the PO group had nearly the same value in both POCIa and POFa, and the one for the PS group had nearly the same value in both PSF a and PSCIa. The potential constants determined had the following values in md/ A: For POCIa, jPO=9.890, jpCl=2.466, jpC1PCl=0.399, for PSCla, jpg = 0.030, jpCl=2.466, jpclPCl=0.399; for POFa, jpo=9.890, jPF=5.633, jpFPF=0.483, and for PSFa, jps=2.9694, jPF=5.333, jpFPF=0.183. Finally, the values of the thermodynamic properties for these 'substances were computed for the ideal gaseous state using the rigid rotor harmonic oscillator approximation at 1 atm from 200 0 to 1000 0 K.