.hdb File

RFM File Formats: HITRAN Database Extract

18SEP24
Type
Input, optional.

Description
Records extracted from the HITRAN database (hitran.org)
One of various forms of spectroscopic line data

Filename
Specified in *HIT section of Driver Table using keyword HDBFIL=[filname]

Structure
Header record, followed by multiple data records, each representing a single transition, in order of increasing wavenumber.
The HITRAN database allows records to be extracted in arbitrary format with arbitrary contents. For the RFM to be able to interpret the data the following formatting options should be selected:
Field separator: [space]
Line endings: Linux/Unix/Mac (LF)
Tick the box for 'Fixed Width Format'
Tick the box for 'Output header line'
and the output should look something like this: [rfm_basic.txt]

Note the '#' characters filling the field width if there is no value in the database for a line parameter.

To ensure that the RFM always has a sufficient set of parameters to model the line, the following parameters should always be selected (these are all included in the standard HITRAN .par file structure, they should always have valid fields). These can be in any order but this follows the sequence in the HITRAN .par file.

Required Parameters
Header Symbol Description Units
molec_id Molecule ID HITRAN molecule ID
local_iso_id Isotopologue ID Isotopologue local ID
nu ν Wavenumber cm-1
sw S Intensity (line strength) @296K cm-1/(molec.cm-2)
gamma_air γair Air-broadened half-width@296K cm-1atm-1
elower E" Lower-state energy cm-1
n_air nair Temperature exponent of γair
gamma_self[1] γself Self-broadened half-width@296K cm-1atm-1
delta_air[1] δair Air pressure-induced line shift@296K cm-1atm-1
[1] Although not strictly necessary since there are default values (γself → γair, δair → 0) these are included in the regular HITRAN .par file structure)

The following parameters are not part of the HITRAN .par file structure and in most cases are likely to be undefined (indicated by a series of # characters filling the format field width). The RFM uses the pattern-matching listed under 'Header' to identify these (having first excluded header fields containing -err or -ref)
Optional Parameters
Header Symbol Description Units
n_* n Temperature exponent of γ
n_y_* nY Temperature exponent of Y
delta_* δ Pressure-induced line shift cm-1atm-1
delta_*_2_* δ2 Speed-dependence of δ cm-1atm-1
deltap_* δ' Linear T-dependence of δ cm-1atm-1K−1
eta_* η Correlation parameter
gamma_*_2_* γ2 Speed-dependence of γ cm-1atm-1
kappa_ κ Temperature exponent of ν
nu_ ν Freq. of velocity-changing collisions cm-1atm-1
y_* Y Line coupling coefficient

Notes
The general form of the variable in the file header is
param_[model]_[env]_[temref]
where, if present,
[model] is one of: ht (Hartmann-Tran), sdv (Speed-dependent Voigt) or g (Galatry). Default: Voigt.
[env], the background gas, is one of: air, self, h2o, h2 or he. Default: air.
[temref], the reference temperature, is one of: 50, 150, 296 or 700. Default: 296.
Apart from self, these are all ignored by the RFM, which just reads through the data record taking the last valid entry of any parameter. It is up to the user to decide the appropriate parameters for any situation, and acceptable alternatives.