Vibrational and X-ray Studies of the Polymorphic Forms of LiIn(MoO4)2

IR and Raman studies of the low- and high-temperature phases of LiIn(MoO4)2 were performed at ambient temperature. The crystal structure of the low-temperature modification was solved. The observed vibrational modes were assigned to the vibrations of respective atoms in the unit cells. The origin of brown coloration and unusual shift of stretching vibrations toward higher energy, observed for the low-temperature polymorph, were explained as a result of instability of wolframite- type structure containing MoO6 octahedra.