Spectroscopic study of the 14NH radical in vibrationally excited levels of the X3Σ− state by far infrared laser magnetic resonance

Abstract

Rotational transitions of vibrationally excited NH (ν = 1 and 2) in the ground X3Σ− electronic state have been detected by far-infrared laser magnetic resonance. The first four rotational intervals were investigated (N = 1 − 0, 2 − 1, 3 − 2, and 4 − 3) with a total of 17 far-infrared laser lines ranging in wavelength from 81.1 to 373.6 µm. For some rotational intervals, transitions between all components of the Zeeman manifolds were observed. An effective Hamiltonian was used to model the experimental measurements. The magnetic hyperfine parameters have been determined for the first time for the ν = 2 level and have been significantly improved for the ν = 1 level. In addition, the rotational, centrifugal distortion, spin-spin, spin-rotation, and Zeeman parameters have all been experimentally determined for the ν = 1 and 2 levels of NH.