J/MNRAS/448/1704 ExoMol line lists for formaldehyde H2CO (Al-Refaie+, 2015)
ExoMol line lists.
VIII: A variationally computed line list for hot formaldehyde.
Al-Refaie A.F., Yachmenev A., Tennyson J., Yurchenko S.N.
<Mon. Not. R. Astron. Soc. 448, 1704 (2015)>
=2015MNRAS.448.1704A 2015MNRAS.448.1704A
ADC_Keywords: Models, atmosphere ; Spectra, infrared ; Spectra, ultraviolet
Keywords: molecular data - opacity - planets and satellites: atmospheres -
stars: atmospheres - ISM: molecules
Abstract:
A computed line list for formaldehyde, H212C16O, applicable to
temperatures up to T=1500K is presented. An empirical potential energy
and ab initio dipole moment surfaces are used as the input to nuclear
motion program TROVE. The resulting line list, referred to as AYTY,
contains 10.3 million rotational-vibrational states and around 10
billion transition frequencies. Each transition includes associated
Einstein- A coefficients and absolute transition intensities, for
wavenumbers below 10000cm-1 and rotational excitations up to J=70.
Room-temperature spectra are compared with laboratory measurements and
data currently available in the HITRAN database. These spectra show
excellent agreement with experimental spectra and highlight the gaps
and limitations of the HITRAN data. The full line list is available
from the CDS database as well as at www.exomol.com.
Description:
The data are in two parts. The first, h2co_0-70.dat contains a list of
10,296,998 rovibrational states.
Each state is labelled with: 6 normal mode vibrational quantum
numbers, and the vibrational symmetry; three rotational quantum
numbers including the total angular momentum J, the projection of J in
the z-axis K,rotational symmetry and the total symmetry quantum number
Gamma In addition there are six local mode vibrational numbers and the
largest coeffecient used to assign the state in question. 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 100 separate
files, each containing all the transitions in a 100cm-1 frequency
range. These and their contents are ordered by increasing frequency.
The name of the file includes the lowest frequency in the range; thus
the a-00500.dat file contains all the transitions in the frequency
range 500-600cm-1.
The transition files contain three columns: the reference number in
the energy file of the upper state; that of the lower state; and the
Einstein A coefficient of the transition. The energy file and the
transitions files are zipped, and need to be extracted before use.
There is a Fortran 90 programme, s_AYTY.f90 which may be used to
generate synthetic spectra (see s_AYTY.txt for details). Using this,
it is possible to generate absorption or emission spectra in either
'stick' form or else cross-sections convoluted with a gaussian with
the half-width at half maximum being specified by the user, or with a
the temperature-dependent doppler half-width. Sample input files
s_*.inp for use with s_SAlTY.f90 are supplied.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
s_AYTY.f90 172 585 Programme for generating spectra
s_sti750.inp 177 116 Illustration of 'stick' input file
s_dop296.inp 175 116 Illustration of 'doppl' input file
s_gau296.inp 175 116 Illustration of 'gauss' input file
s_bin750.inp 175 116 Illustration of 'bin' input file
s_pfu296.inp 175 116 Illustration of 'partfunc' input file
s_AYTY.txt 184 85 Explanation of input structure for s_AYTY.f90
h2co_0-70.dat 128 10296998 labelled rovibrational states
ayty/* . 100 *Individual files of frequency-ordered transitions
--------------------------------------------------------------------------------
Note on ayty/*: 12,688,112,827 transitions are in 100 files labelled
"a-0NN00.dat" (NN between 00 and 99). Each file corresponds to
frequency-ordered transitions, 0NN00 to 0NN00+100 cm-1.
--------------------------------------------------------------------------------
See also:
J/MNRAS/425/34 : ExoMol line lists for BeH, MgH and CaH (Yadin+, 2012)
J/MNRAS/434/1469 : ExoMol line lists for SiO (Barton+, 2013)
J/MNRAS/437/1828 : ExoMol line list for HCN and HNC (Barber+, 2014)
J/MNRAS/440/1649 : ExoMol line lists for CH4 (Yurchenko+, 2014)
J/MNRAS/442/1821 : ExoMol line list for KCl (Barton+, 2014)
J/MNRAS/445/1383 : ExoMol line list for PN (Yorke+, 2014)
J/MNRAS/446/2337 : ExoMol line lists for PH3 (Sousa-Silva+, 2015)
J/MNRAS/449/3613 : ExoMol line lists for AlO (Patrascu+, 2015)
J/MNRAS/451/5153 : ExoMol line lists for NaH and NaD (Rivlin+, 2015)
Byte-by-byte Description of file: h2co_0-70.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 I12 --- i [1/10296998] State ID, non-negative integer
index, starting at 1
14- 25 F12.6 cm-1 E [0/25125] State energy term value in cm-1
27- 32 I6 --- g [1/423] Total state degeneracy
34- 39 I6 --- J [0/70] J-quantum number, total angular momentum
excluding nuclear spin
43- 45 I3 --- G [1/4] Total symmetry Γ (1)
47- 49 I3 --- v1 [0/10] normal mode vibrational quantum number
51- 53 I3 --- v2 [0/16] normal mode vibrational quantum number
55- 57 I3 --- v3 [0/11] normal mode vibrational quantum number
59- 61 I3 --- v4 [0/16] normal mode vibrational quantum number
63- 65 I3 --- v5 [0/10] normal mode vibrational quantum number
67- 69 I3 --- v6 [0/16] normal mode vibrational quantum number
73- 76 I4 --- Gv [1/4] Vibrational symmetry Γviv (1)
79- 81 I3 --- K [0/70] Projection of J on z-axis
86- 88 I3 --- Gr [0/4] Rotational symmetry Γrot (1)
90- 97 I8 --- N(Bl) [1/67238] Reference number in the polyad
101-104 F4.2 --- C2 [0/1] Square of the largest coefficient
106-108 I3 --- n1 [0/11] Local mode vibrational quantum number
110-112 I3 --- n2 [0/10] Local mode vibrational quantum number
114-116 I3 --- n3 [0/10] Local mode vibrational quantum number
118-120 I3 --- n4 [0/16] Local mode vibrational quantum number
122-124 I3 --- n5 [0/16] Local mode vibrational quantum number
126-128 I3 --- n6 [0/16] Local mode vibrational quantum number
--------------------------------------------------------------------------------
Note (1): H2CO is a prolate asymmetric top molecule that belongs to the
C2 molecular symmetry group. This group has 4 irreducible representations
A1,A2,B1,B2 (see Bunker & Jensen 1998, "Molecular Symmetry and
Spectroscopy", 2nd edn. NRC Research Press, Ottawa); the values of Γ
correspond to the modes 1=A1, 2=A2, 3=B1, and 4=B2.
--------------------------------------------------------------------------------
Byte-by-byte description of file: ayty/*
-------------------------------------------------------------------------------
Bytes Format Units Label Explanations
-------------------------------------------------------------------------------
1- 12 I12 --- i1 [2/10296998] Upper state ID
15- 26 I12 --- i0 [1/10296998] Lower state ID
29- 38 E10.4 s-1 A Einstein A-coefficient of the transition
-------------------------------------------------------------------------------
Acknowledgements:
Ahmed F. Al-Refaie, ahmed.al-refaie.12(at)ucl.ac.uk
S.N. Yurchenko, s.yurchenko(at)chemie.tu-dresden.de
J. Tennyson, j.tennyson(at)ucl.ac.uk
References:
Tennyson & Yurchenko, 2012MNRAS.425...21T 2012MNRAS.425...21T
Yadin et al., Paper I, 2012MNRAS.425...34Y 2012MNRAS.425...34Y, Cat. J/MNRAS/425/34
Barton et al., Paper II 2013MNRAS.434.1469B 2013MNRAS.434.1469B, Cat. J/MNRAS/434/1469
Barber et al., Paper III 2014MNRAS.437.1828B 2014MNRAS.437.1828B, Cat. J/MNRAS/437/1828
Yurchenko & Tennyson, Paper IV 2014MNRAS.440.1649Y 2014MNRAS.440.1649Y, Cat. J/MNRAS/440/1649
Barton et al., Paper V 2014MNRAS.442.1821B 2014MNRAS.442.1821B, Cat. J/MNRAS/442/1821
Yorke et al., Paper VI 2014MNRAS.445.1383Y 2014MNRAS.445.1383Y, Cat. J/MNRAS/445/1383
Sousa-Silva et al., Paper VII 2015MNRAS.446.2337S 2015MNRAS.446.2337S, Cat. J/MNRAS/446/2337
Patrascu et al., Paper IX 2015MNRAS.449.3613P 2015MNRAS.449.3613P, Cat. J/MNRAS/449/3613
Rivlin et al., Paper X 2015MNRAS.451.5153R 2015MNRAS.451.5153R, Cat. J/MNRAS/451/5153
(End) Ahmed F. Al-Refaie [UCL], Patricia Vannier [CDS] 29-Jan-2015