Abstract
The infrared polarized reflection spectra of piezoelectric lithium formate monohydrate single crystal has been measured at two temperatures (295°K and 10°K) in the range 300-3500 cm-1. The interpretation of the results shows that the symmetry m of the formate ion is due to an asymmetric crystalline field. New H2O stretching mode assignments are given, implying the formation of an infinite chain of water-oxygens. The temperature effects are characteristic of each type of mode. The dispersion parameters and the optical constants are given.