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

Abstract

. A spectroscopic study of the 14NH radical in vibrationally excited levels of the X 3Σ-state by far-infrared laser magnetic resonance. Molecular Physics, Taylor Francis, 2007, 105 (05-07), pp

The far-infrared and microwave spectra of the CH radical in the v=1 level of the X2Π state

“…The present result tells us that these effects get larger with vibrational excitation. This behaviour is the same as that observed recently for the NH radical [23].…”

“…It is quite a complicated exercise to estimate the uncertainty of each individual resonance. Consequently, we have assigned the same uncertainty of 2 MHz to each resonance; this is a figure based on experience of making such measurements in a range of far-infrared LMR spectra [11,17,23].…”

“…Evenson at the Boulder laboratories of NIST. The spectrometer has been described in detail in previous papers [22,23]. The CH radicals were produced in the sample volume of the spectrometer by the reaction of fluorine atoms with methane in a flow system, the fluorine atoms being generated by passing 150 mtorr (20 Pa) of a 5% mixture of fluorine in helium together with 1 torr (133 Pa) of helium through a microwave discharge operating at 2450 MHz.…”

Revised molecular constants and term values for the X3Σ− and A3Π states of NH

“…An explicit listing of the 3 R À Hamiltonian matrix elements was provided in our previous paper on NH [2]. The current set of measurements of the observed lines from the laboratory spectra have been combined with the lines of the A 3 P-X 3 R À transition [2] and other previously reported vibration-rotation lines [34], zero field pure rotational lines [5][6][7]35] and solar pure rotational lines [24] of the ground state using suitable weights.…”

“…Several new measurements of the pure rotational transitions have been made recently in order to derive more precise rotational, distortion and hyperfine parameters for astronomical applications [5][6][7]. Lewen et al [5] have measured the 14 N nuclear hyperfine patterns accompanying the N = 2 1 rotational transition, while Brown and coworkers [6,7] have reported the observation of hyperfine structure associated with transitions up to N = 5 4 in the v = 0 vibrational level and up to N = 4 3 for the v = 1 and 2 vibrational levels, and have determined an improved set of spectroscopic and hyperfine parameters for the v = 0, 1 and 2 vibrational levels. In addition to the triplet states, there are four low-lying singlet electronic states, a 1 D, b 1 R + , c 1 P and d 1 R + .…”