Data on the interpretation of the IR and Raman spectra Data on the interpretation of the IR and Raman spectra based on normal coordinate analysis, on the force constants and based on normal coordinate analysis, on the force constants and on the conformations of the molecules of trivalent tricoordinate on the conformations of the molecules of trivalent tricoordinate phosphorus compounds are summarised. The existing correla-phosphorus compounds are summarised. The existing correlations between the spectra and molecular structures are refined and tions between the spectra and molecular structures are refined and some new correlations are proposed. The bibliography includes some new correlations are proposed. The bibliography includes 171 references 171 references. .