Abstract
Experimental results of tunnel splitting of the fundamental vibration of the CN- ion in a KBr matrix are presented from which the direction of the dipolar alignment is deduced as (111). The potential barriers for reorientation of the CN- ion in the KCl and KBr lattices are calculated as 28.7 and 36.5 cm-1 respectively. From this comparative study, the author infers that the anisotropic part of the interionic potential giving rise to a barrier for reorientation is determined by the attractive part rather than the repulsive part of the potential.