The anharmonic constants and average structure of ammonia

Morino, Yonezo; Kuchitsu, K.; Yamamoto, Seiya

doi:10.1016/0584-8539(68)80047-9

Cited by 114 publications

(20 citation statements)

References 29 publications

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“…There are several reasons which can be given to explain why the structure [1][2][3][4][5][6][7][8][9][10] and the spectra [2,8, of the ammonia molecule have been the subject of a large number of experimental and theoretical investigations. In what follows we focus on spectroscopic issues most relevant for our own study presented here: (1) Ammonia is a simple, stable four-atomic chemical species.…”

Section: Introductionmentioning

confidence: 99%

MARVEL analysis of the measured high-resolution spectra of 14NH3

Derzi

Furtenbacher

Tennyson

et al. 2015

Journal of Quantitative Spectroscopy and Radiative Transfer

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a b s t r a c tAccurate, experimental rotational-vibrational energy levels and line positions, with associated labels and uncertainties, are reported for the ground electronic state of the symmetric-top 14 NH 3 molecule. All levels and lines are based on critically reviewed and validated high-resolution experimental spectra taken from 56 literature sources. The transition data are in the 0.7-17 000 cm À 1 region, with a large gap between 7000 and 15 000 cm À 1 . The MARVEL (Measured Active Rotational-Vibrational Energy Levels) algorithm is used to determine the energy levels. Out of the 29 450 measured transitions 10 041 and 18 947 belong to ortho-and para-14 NH 3 , respectively. A careful analysis of the related experimental spectroscopic network (SN) allows 28 530 of the measured transitions to be validated, 18 178 of these are unique, while 462 transitions belong to floating components. Despite the large number of spectroscopic measurements published over the last 80 years, the transitions determine only 30 vibrational band origins of 14 NH 3 , 8 for ortho-and 22 for para-14 NH 3 . The highest J value, where J stands for the rotational quantum number, for which an energy level is validated is 31. The number of experimental-quality ortho-and para-14 NH 3 rovibrational energy levels is 1724 and 3237, respectively. The MARVEL energy levels are checked against ones in the BYTe firstprinciples database, determined previously. The lists of validated lines and levels for 14 NH 3 are deposited in the Supporting Information to this paper. Combination of the MARVEL energy levels with first-principles absorption intensities yields a huge number of experimental-quality rovibrational lines, which should prove to be useful for the understanding of future complex high-resolution spectroscopy on 14 NH 3 ; these lines are also deposited in the Supporting Information to this paper.

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Section: Introductionmentioning

confidence: 99%

MARVEL analysis of the measured high-resolution spectra of 14NH3

Derzi

Furtenbacher

Tennyson

et al. 2015

Journal of Quantitative Spectroscopy and Radiative Transfer

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“…There has been a lot of work studying the H-B-N system, including aminoborane ͑NH 2 BH 2 ͒, 10,11 imodoborane ͑NHBH͒, 12 gas-phase borane ͑BH 3 ͒, 13,14 ammonia ͑NH 3 ͒, [15][16][17] and other related compounds. From a chemical point of view, ammonia borane is an unusual bonding system involving hydrogen-hydrogen interaction between the protonic ͑NH͒ and hydridic ͑BH͒ hydrogen atoms of adjacent molecules.…”

Section: Introductionmentioning

confidence: 99%

Raman spectroscopy study of ammonia borane at high pressure

Lin

Mao

Drozd

et al. 2008

The Journal of Chemical Physics

100

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Ammonia borane, NH(3)BH(3), has attracted significant interest as a promising candidate material for hydrogen storage. The effect of pressure on the bonding in NH(3)BH(3) was investigated using Raman spectroscopy to over 20 GPa in a diamond anvil cell, and two new transitions were observed at approximately 5 and 12 GPa. Vibrational frequencies for the modes of the NH(3) proton donor group exhibited negative pressure dependence, which is consistent with the behavior of conventional hydrogen bonds, while the vibrational frequencies of the BH(3) proton acceptor group showed positive pressure dependence. The observed behavior of these stretching modes supports the presence of dihydrogen bonding at high pressure. In addition, the BH(3) and NH(3) bending modes showed an increase in spectral complexity with increasing pressure together with a discontinuity in d nu/d P which suggests rotational disorder in this molecule. These results may provide guidance for understanding and developing improved hydrogen storage materials.

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“…The results of the calculations are shown in Table 1 as vca]c (II). It is to be noted that the inversion barrier of 1810 cm"1 of the new calculation is close to that found in [4] and [5], where only limited interaction between inversion motion and other motions was permitted. Further details of the present calculations will be presented in another publica tion.…”

Section: Resultsmentioning

confidence: 80%

“…In the previously reported full variational calculation, the ammonia potential was taken to be the sum of two terms, V r x and V g. V r ^ is a potential involving the dis placements of N-H stretching coordinates and H-N -H bending coordinates from their respective equilibrium values which was derived from a potential obtained by Morino et al [5] by fitting perturbation theory formulae to spectroscopic data without taking into account the double minimum problem of the inversion. V0 is an in version barrier double minimum potential which is of a form used by Swalen and Ibers [2 b] and which contains three parameters.…”

Section: Introductionmentioning

confidence: 99%