Spectral intensities in the ν 1 band of NH 3

Abstract

Intensities have been measured for individual transitions in the Q and R branches of the ν 1 band of NH 3 using a difference-frequency laser spectrometer. The data yield an integrated band strength of S 0 v =219.36±1.03 cm -2/ MPa at 297 K, corresponding to a transition moment of ∣ μ v ∣ = 8.535(20) × 10 -32 C· m, and a Herman-Wallis correction factor, (1 + α jm ) 2, where α j = 0.0209(20). The intensities of a few lines for K ⩾ 7 were noticeably perturbed by a perpendicular Coriolis interaction with 2 ν 4 ( E, l = 2), so were excluded from the fit. A small sample of ν 3 band lines occurring in the ν 1 band scans also yields a rough estimate of the ν 3 band intensity with evident irregular perturbations.