Unusual luminescence from uranyl nitrate

A short range force constant model has been applied for the first time to investigate the phonons in NdGaO3 perovskite in the orthorhombic phase. The calculations of phonons have been made with 10 stretching and 10 bending force constants. The calculated values of Raman and infrared frequencies are in good agreement with the observed ones. The infrared frequencies have been assigned for the first time.