The infra-red and Raman spectra of KCu(CN)2 have been assigned in terms of the known structure. There are no coincidences, and in the CuC stretching and CuCn bending regions there is evidence of factor group splittings at room temperature. On cooling the solid to 15oK there is no evidence of a phase change, but there is significant increase in the signal-to-noise ratio which allows confirmation of the assignments made from room temperature data. Assignments were made for the four components of eight out of the ten fundamentals. No assignments were possible for V4, the totally symmetric CCuC bending vibration and V10, the interionic CuN stretching vibration.


S U QURESHI ,B M CHADWICK ,D A LONG ,