000			03266nab a2200313 c 4500
001			vtls000569502
003			RU-ToGU
005			20210907031653.0
007			cr |
008			170407|2015 enk s a eng|dd
024	7		_a10.1016/j.jqsrt.2015.06.009 _2doi
035			_ato000569502
040			_aRU-ToGU _brus _cRU-ToGU
100	1		_aRey, Michaël _9112225
245	1	0	_aConvergence of normal mode variational calculations of methane spectra: Theoretical linelist in the icosad range computed from potential energy and dipole moment surfaces _cM. Rey, A. V. Nikitin, V. G. Tyuterev
504			_aБиблиогр.: 47 назв.
520	3		_aAccurate basis set convergence of first-principles predictions of rotationally resolved spectra at high energy range is a common challenging issue for variational methods. In this paper, a detailed convergence study for the methane spectra is presented both for vibrational and rotational degrees of freedom as well as for intensities. For this purpose, we use our previously reported nine-dimensional potential energy and dipole moment surfaces of the methane molecule [Nikitin et al. Chem Phys Lett 2011;501:179–86; 2013;565:5–11]. Vibration–rotation calculations were carried out using variational normal mode approach with a full account of the Td symmetry. The aim was to obtain accurate theoretical methane line lists for the wavenumber range beyond currently available spectra analyses. The focus of this paper is the complicated icosad range (6280–7900 cm−1) containing 20 bands and 134 sub-bands where over 90% of experimental lines still remain unassigned. We provide variational line lists converged to a “spectroscopic precision” for icosad transitions for T=80 K and T=296 K. The first one contains 70 300 lines and the second one 286 170 lines with the intensity cut-off View the MathML source10−29cm−1/(moleculecm−2) with Jmax=18. An average error in line positions of theoretical predictions up to J=15 is estimated as 0.2–0.5 cm−1 from the comparisons with currently analyzed bands. Ab initio line strength calculations give the integrated intensity View the MathML source4.37×10−20cm−1/(moleculecm−2) at T=80 K for the sum of all icosad bands. This is to be compared to the integrated intensity View the MathML source4.36×10−20cm−1/(moleculecm−2) of the experimental icosad line list recorded in Grenoble University [Campargue et al., J Mol Spectrosc 2013;291:16–22] using very sensitive laser techniques. The shapes of absorption bands are also in a good qualitative agreement with experimental spectra.
653			_aпотенциальная энергия
653			_aдипольный момент
653			_aметан
655		4	_aстатьи в журналах _9681159
700	1		_aNikitin, Andrei V. _996598
700	1		_aTyuterev, Vladimir G. _996138
773	0		_tJournal of Quantitative Spectroscopy and Radiative Transfer _d2015 _gVol. 164. P. 207-220 _x0022-4073
852	4		_aRU-ToGU
856	7		_uhttp://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000569502
908			_aстатья
999			_c422239