Thev₂spectrum of NH₃

Abstract

The v2 spectrum of NHa has been obtained with a resolution of 0.0050 cm -1 on the Kitt Peak McMath Fourier Transform spectrometer in the wavenumber range between 720 and 1300 cm -1. 489 lines have been assigned up to J=ll in the P branches, J=17 in the Q branches and J=16 in the R branches. A least squares analysis of this spectrum yields considerably improved term values and effective molecular constants for the v 2 state. The root mean square deviation of the least squares fit is 0.00019 cm -1. Our observed lines are in excellent agreement (root mean square deviation = 0-000050 cm 1) with the limited number of laser heterodyne measurements that have been reported recently by Sattler and coworkers and by Hillman. The ground state energies have been revised to include our new determination of the C, Dn, Hn and LK constants and have been extended to a higher J= 17 than given in our earlier report.

Submillimeter-wave and far-infrared spectroscopy of high-J transitions of the ground and ν2=1 states of ammonia

“…The operator code for this interaction is 600VV in the SPFIT/ SPCAT programs A total of 4394 transitions were included in the current analysis, including 2166 transitions assigned in this study and 2228 transitions from previous microwave studies 16,[29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45] and infrared studies. [46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62] Each of the 4394 transitions was weighed by its experimental uncertainty. The details for all previously available transitions are available in Ref.…”

The infrared spectrum of NH3-dn trapped in solid neon

“…1. At the top of this figure, the positions of the gas-phase absorptions which arise from the J ¼ 0 and J ¼ 1 levels of NH 3 , given by Poynter and Margolis [5], are also shown. The gas-phase m 2 fundamental exhibits an inversion splitting of 35.7 cm À1 , resulting in two series of lines which are usually designated by ''s'' and ''a.''…”

“…Since 1980, higher resolution spectra and more detailed assignments have been reported for all of the fundamentals of NH 3 [5][6][7] and ND 3 [8,9], for m 2 of NH 2 D and NHD 2 [10][11][12][13], and for the stretching fundamentals of NHD 2 [14]. The m 2 transition of NH 3 has been studied for that molecule attached to the surface of argon clusters [15] and embedded in helium clusters [16].…”

HOT NH3SPECTRA FOR ASTROPHYSICAL APPLICATIONS

“…Over the years, numerous studies have been undertaken to assign the complicated NH 3 spectrum (Poynter & Margolis 1983, 1984Sasada et al 1992;Kleiner et al 1999;Cottaz et al 2000;Lees et al 2008). Many studies are of cold NH 3 and are useful when studying planetary atmospheres in our solar system (Brown & Margolis 1996).…”