EXPERIMENTAL NONADDITIVITY OF PRESSURE LINESHIFTS IN THE SYSTEM OF TRANSITIONS OF THE AMMONIA MOLECULE

Experimental evidence of inequality of algebraic sums of pressure line shift parameters of transitions along different paths connecting the s ame initial and final energy levels in the spectrum of the ammonia mol ecule is demonstrated. Though such a possibility follows, e.g., from d ifferent values of parameters of nearest approach of perturbing molecu les bo for different transitions in Anderson-type theories (and simila r effects in other theories), up to now it lacked experimental evidenc e. Some consequences of the phenomenon and further studies are discuss ed. (C) 1996 Academic Press, Inc.