TEMPERATURE-DEPENDENCE OF SELF-SHIFT OF AMMONIA TRANSITIONS IN THE NU(2) BAND

Pressure-induced lineshift has been measured as a function of temperat ure, in the range 200-400 K, for five transitions of the v(2) band of ammonia lines near 937 cm(-1). Results are compared with semiclassical calculations that rely on the impact approximation. In general the th eory does not agree very well with the experimental values of the shif t, but the sign and the order of magnitude are confirmed. The present work shows that extensive and detailed measurement of the lineshifts i s feasible and reliable, even when their absolute values in ammonia as a function of temperature are very small. Copyright (C) 1996 Elsevier Science Ltd