*HIT Section

03JUL26

Type

Description

Spectroscopic Database file (i.e. HITRAN binary file)

Structure

Single Field, or (v04JUL26 onwards) multiple PARAM=VALUE records, order is significant

Field	Type	Description
Either:
BINFIL	C200	Name of spectroscopic .bin file
Or: (v04JUL26 onwards)
`BINFIL=`BINFIL	C200	Name of spectroscopic .bin file
`PARFIL=`PARFIL	C200	Name of spectroscopic .par file
`MRGFIL=`MRGFIL	C200	Name of saved merged .bin file

(v04JUL26) Qualifiers may also be directly appended to filenames

Qualifier Type Description
(GAS1; GAS2; ... ) C Molecules to be included from file
(-GAS1; GAS2; ... ) C Molecules to be excluded from file
(WNOMIN:WNOMAX) D Wavenumber range of file [cm^-1]
Type: D=Double Precision; Cn=character string, length n.

Qualifier	Type	Description
`(`GAS1`;` GAS2`; ... )`	C	Molecules to be included from file
`(-`GAS1`;` GAS2`; ... )`	C	Molecules to be excluded from file
`(`WNOMIN`:`WNOMAX`)`	D	Wavenumber range of file [cm^-1]

Notes

A spectroscopic database file is required if any absorbing molecules have HITRAN ID less than 100 (which will usually be the case) AND corresponding Look Up Tables are not available. If using LUTs it is better to put the *LUT section before the *HIT section so that MORSE knows which molecules, if any, still require spectroscopic data before reading the files listed in this section.
The binary file is the same format as used by the RFM, and can be created from a HITRAN ASCII file using program HITBIN
From v04JUL26 onwards:
BINFIL: If just using a single binary file it is best to continue to define it using just the filename (i.e., without the BINFIL= keyword). MORSE will then use the file directly without attempting to create its own (reduced) version of the file.
With the BINFIL and/or PARFIL keywords a combination of multiple files can be used, with the lines in the later files replacing any duplicate lines within the former files. The check for duplicate lines is any matching molecule and isotope lying within 0.001 cm^-1 (set by parameter WNODUP in module hitmrg_sub.f90). A list of removed lines are included in the morse.log file.
MRGFIL: When merging files, or using single files specified by BINFIL or PARFIL keywords, MORSE automatically creates its own binary file covering just the required molecules and spectral range(s). This is to provide fast, repeated access (a large .par in particular would have to be re-read all the way through from the beginning of the file each iteration). Normally this is a Fortran Scratch file: transparent to the user and deleted at the end of the run (unless the program crashes unexpectedly), but with the MRGFIL keyword you can save the file for re-use as a direct BINFIL for subsequent runs requiring the same spectroscopic data.
GASn: qualifiers, either HITRAN indices or molecule names (case-insensitive), separated by semi-colons, may be used either to specify a subset of molecules to include from a particular file; or, if the list starts with a '-' sign, molecules to exclude from the file. This can be used to override the automatic merging/replacement where molecules are present in more than one input file. Qualifiers do not have to be among the required absorbers, and the morse.log file lists which molecules are actually taken from each file.
WNOMIN:WNOMAX: used to restrict the spectral range of the file. Either limit can be replaced by '*' so that the actual file limit is used. Note that for line-by-line calculations MORSE uses lines up to 25 cm^-1 from the microwindow boundaries so any specified limits should include this margin. This also means that this cannot be used to select a spectroscopic data file for use with just one microwindow where other microwindows lie within this +/- 25 cm^-1 limit.

Example

Simple version using binary file directly:

*HIT ../morse_files/hitran_2020.bin

Using single HITRAN .par file:

*HIT PARFIL=hitran_2024.par MRGFIL=hitran.bin ! (optional) to save created binary for reuse

Using multiple files with qualifiers:

*HIT BINFIL=../morse_files/hitran_2020.bin PARFIL=hitran_2024.par(co2;h2o) ! update CO2 and H2O only PARFIL=o3.par ! supplementary O3 lines PARFIL=h2o.par(2500:*) ! supplementary H2O lines above 2500 cm-1 MRGFIL=merged.bin ! save created binary for reuse