ExoMol Line List. XXI Nitric Oxide (NO). (2017)
Keywords :
planetary systems - astronomical data bases - physical data and processes
Abstract:Line lists for the ground electronic ground state for the parent isotopologue of nitric oxide and five other major isotopologues are presented. The line lists are constructed using empirical energy levels (and line positions) and high-level ab inito intensities. The energy levels were obtained using a combination of two approaches, from an effective Hamiltonian and from solving the rovibronic Schroedinger equation variationally. The effective hamiltonian model was obtained through a fit to the experimental line positions of NO available in the literature for all six isotopologues using the programs SPFIT and SPCAT. The variational model was built through a least squares fit of the ab inito potential and spin-orbit curves to
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The states files contain lists of rovibronic states. Each state is
labelled with the total angular momentum, state degeneracy, total
parity, vibrational quantum number, projection of the electronic, spin
and total angular momenta. Each 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 lifetimes and Lande-g factors are
also provided.
The transition files t_*dat contain four 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
energy file and the transitions files are bzipped, and need to be
extracted before use.
The p_*.dat files contain the partition functions for the six
isotopologues (0...5000K) tabulated in steps of 1K. The pf_param.dat
contains unitless expansion parameters a_i of the partition functions
extrapolated using the following form (Vidler & Tennyson, 2000,
J. Chem. Phys., 113, 9766): log10(Q) = sum_i a_i [log10(T)]^i
A sample programme to generate synthetic spectra from the ExoMol
format line lists can be obtained at www.exomol.com.
J. Tennyson, j.tennyson(at)ucl.ac.uk S.N. Yurchenko, s.yurchenko(at)ucl.ac.uk