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To complete the analysis of the complex infrared spectra of 14NH3in the 4- to 8-μm region, we assigned nearly 1200 transitions in the 3ν2−ν2, ν2+ν4−ν2, ν1−ν2, ν3−ν2, 2ν4−ν2and 4ν2−ν2hot bands using the upper state energy levels determined by our previous studies at 4 and 3 μm (J. Mol. Spectrosc.173, 120–145 (1995); 193, 46–71 (1999)). Line intensities of those hot bands were analyzed using measurements retrieved from 0.0056 and 0.011 cm−1unapodized resolution FT spectra recorded at Kitt Peak National Observatory. By a least-squares fit of vibrational-inversion transition moments, over 770 intensity measurements are modeled to ±7.2% and ±8.9% in the 5- to 8-μm and 4-μm regions, respectively. The values of the transition dipole moment were determined to obtain the band strengths of hot bands. In the 5- to 8-μm region, the band strengths in cm−2atm−1at 296 K of 3ν2−ν2(a←s), 3ν2−ν2(s←a), ν2+ν4−ν2(s←s) and ν2+ν4−ν2(a←a) were found to be 0.000075(23), 0.351(22), 0.689(32), and 0.525(44), respectively. In the 4-μm region, for the ν3−ν2(s←s), ν3−ν2(a←a), 2ν4l4=±2−ν2(s←s), and ν4l4=±2−ν2(a←a), they were estimated to be 0.0703(32), 0.0599(27), 0.00547(34), and 0.00473(29), respectively at 296 K. Also, about 100 line intensities of the ν1−ν2(a←s), ν1−ν2(s←a), 2ν4l4=0−ν2(a←s), 2ν4l4=0−ν2(s←a), and 4ν2−ν2(s←a) weak hot bands were measured and reported. The prediction generated by the present study is available for the detection of 14NH3in exoplanet atmospheres and brown dwarf stars with relatively high temperature (∼1000 K). A few self-broadened linewidths are reported to demonstrate that there is a large variation with the vibrational quanta.

Line positions and intensities belonging to the vibrational system 2ν2/ν4of ammonia 14NH3are measured and analyzed between 1200 and 2200 cm−1in order to improve the molecular database. For this, laboratory spectra are obtained at 0.006 and 0.011 cm−1unapodized resolution and with 4% precisions for the intensities using Fourier transform spectrometers located at the Kitt Peak National Observatory and the Jet Propulsion Laboratory. The observed data contain transitions of the ν4fundamental band near 1626.276(1) and 1627.375(2) cm−1(for sand ainversion upper states, respectively) and the 2ν2overtone band near 1597.470(3) and 1882.179(5) cm−1(for sand ainversion states, respectively). A total of 2345 lines with J′ ≤ 15 is assigned from which 2114 line positions with J′ ≤ 15 are fitted using an effective rotation–inversion–rotation Hamiltonian to achieve an rms of 0.003 cm−1with 57 molecular parameters. Over 1200 intensity measurements are modeled to ±4.7% using 16 terms of the dipole moment expansion. A dyad model is used in order to model all the interactions expected within the 2ν2/ν4system. The bandstrengths of 2ν2(s← a), 2ν2(a← s), and ν4(s← sand a← a) are estimated to be 6.68(24), 0.201(5), and 116(3) cm−2atm−1, respectively, at 296 K. The prediction generated by this study is available for planetary studies.