ExoMol molecular line lists. XXXV A rotation-vibration line list for hot ammonia. (2019)
Keywords :
molecular data - opacity - astronomical data bases miscellaneous - planets and satellites: atmospheres - brown dwarfs - stars: low-mass
Abstract:A new hot line list for ^14^NH_3_ is presented. The line list CoYuTe was constructed using an accurate, empirically refined potential energy surface and a CCSD(T)/aug-cc-pVQZ ab initio dipole moment surface of ammonia, previously reported. The line list is an improvement of the ammonia line list BYTe (Yurchenko et al., 2011MNRAS.413.1828Y, Cat. VI/133). The CoYuTe line list covers wavenumbers up to 20000cm^-1^, i.e. wavelengths above 0.5 um for temperatures up to 1500K. Comparisons with the high temperature experimental data from the literature show excellent agreement for wavenubmers below 6000cm^-1^. The CoYuTe line list contains 16.9 billion transitions.
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The states file st-nh3.dat (14N-1H3__CoYoTe.states) contains a list of
rovibrational states. Each state is labelled with normal as well TROVE
local mode vibrational quantum numbers and the vibrational symmetry;
three rotational quantum numbers including the total angular momentum
J and rotational symmetry; the total symmetry quantum number Gamma.
Each rovibrational state has a unique number, which is the number of
the row in which it appears in the file. This number is the means by
which the state is related to the second part of the data system, the
transitions files. The total degeneracy is also given to facilitate
the intensity calculations.
Because of their size, the transitions are listed in 200 separate
files, each containing all the transitions in a 100cm^-1^ frequency
range. These transition files 14N-1H3__CoYoTe__*.trans contain the
Ammonia lines consisting of three columns: the reference number in the
energy file of the upper state, that of the lower state, the Einstein
A coefficient of the transition and the transition wavenumber. These
entries are ordered by increasing frequency. The name of the file
includes the lowest frequency in the range; thus the
14N-1H3__CoYuTe__00500-00600.trans file contains all the transitions
in the frequency range 500-600cm^-1^.
The energy file and the transitions files are bzipped, and need to be
extracted before use.
A programme ExoCross to generate synthetic spectra from these line
lists can be obtained at www.exomol.com.
S.N. Yurchenko, s.yurchenko(at)ucl.ac.uk J. Tennyson, j.tennyson(at)ucl.ac.uk