Raman Scattering Spectra of β-LiNH4SO4 Crystals.

Vibrational spectra of β-LiNH4SO4 crystals in the ferroelectric phase (space group No. 33) are studied. The vibrational symmetry is classified using group-theoretical analysis. Vibrational frequencies of crystal structural elements are calculated ab initio within the framework of electron density functional theory and perturbation theory. Raman scattering spectra of β-LiNH4SO4 crystals are calculated and compared with the experimental data. The main structural components playing one of the major roles in the optical studies are discussed based on the theoretical calculations. [ABSTRACT FROM AUTHOR]