Infrared and Raman spectra of the solid solution Cd1.25Ca0.75P2O7 are presented. The spectra of this phase are unique as a result of the C1 site for P2O7(4-) and the crystal structure of C1(1) which should not result in any splitting of the predicted vibrational modes for this ion with the eclipsed conformation, leaving it essentially free of interference arising due to crystal effects.