摘要
The interna.1 vibrations of the ammonium ion in(ND_(4))_(2) TeCl_(6) have been studied by Raman scattering in the temperature range 4.2-300 K.Split tings of A_(1)-,E-,and T_(2)-modes have been o bserved at T_(c2)=48K and T_(c3)=28 K.These split tings were well interpreted by group theoretical correlation method.The reason for the transitions at T_(c2) and T_(c3) may be the decrease of the force constant in the deuterated ammonium ion.
