HITRAN Format


The HITRAN format is the format defined by the High-resolution Transmission Molecular Absorption (HITRAN) database. It has been widely adopted by the community of spectroscopists and modellers using spectrospcopic data.

Data are stored in a standardized way in formatted ASCII text files. HITRAN conventions are described on the HITRAN Database Web Site under Section "HITRAN Facts".

We reproduce below some of the tables available at the HITRAN site. Tables 1 & 2 display all fields included in one record (one line) of a HITRAN data file. Each table corresponds to a version of the HITRAN database (prior to or after 2000). Table 3 lists molecule numbers and formulæ. Isotope numbers can be found on the HITRAN Web site. Table 4 displays the error codes and their meanings.

Table 1. Format for HITRAN Parameters, Editions 1986 through 2000 – One record includes 16 parameters and is 100 characters long
Parameter Molecule
number
Isotope
number
Transition
frequency
[cm-1]
Line
intensity
|R|2 Air-
broadened
width
Self-
broadened
width
Lower-
state
energy
Temperature
dependence
(of air
width)
Pressure
shift
Upper
vibrational
quanta
Lower
vibrational
quanta
Upper
local
quanta
Lower
local
quanta
Error
code
Reference
code
Field length 2 1 12 10 10 5 5 10 4 8 3 3 9 9 3 6

Table 2. New Format for HITRAN Parameters, Editions after 2000 – One record includes 19 parameters and is 160 characters long
Parameter Molecule
number
Isotope
number
Transition
frequency
[cm-1]
Line
intensity
Einstein-A
coefficient
Air-
broadened
width
Self-
broadened
width
Lower-
state
energy
Temperature
dependence
(of air
width)
Pressure
shift
Upper
vibrational
quanta
Lower
vibrational
quanta
Upper
local
quanta
Lower
local
quanta
Error
code
Reference
code
Flag
for
line
mixing
Upper
statistical
weight
Lower
statistical
weight
Field length 2 1 12 10 10 5 5 10 4 8 15 15 15 15 6 12 1 7 7
FORTRAN
descriptor
i2 i1 f12.6 1pe10.3 e10.3 0pf5.4 f5.4 1pf10.4 0pf4.2 f8.6 a15 a15 a15 a15 6i1 6i2 a1 i7 i7

Table 3. HITRAN molecule numbers
#Molecule #Molecule #Molecule #Molecule #Molecule
1H2O 9SO2 17HI 25H2O2 33HO2
2CO2 10NO2 18ClO 26C2H2 34O
3O3 11NH3 19OCS 27C2H6 35ClONO2
4N2O 12HNO3 20H2CO 28PH3 36NO+
5CO 13OH 21HOCl 29COF2 37HOBr
6CH4 14HF 22N2 30SF6 38C2H4
7O2 15HCl 23HCN 31H2S
8NO 16HBr 24CH3Cl 32HCOOH

Table 4. HITRAN one-digit error codes
Wavenumber [cm-1] Intensity, Halfwidths,
Temperature dependence,
Pressure shift
CodeError rangeCodeError range
0> 1 cm-1 or unreported 0Unreported or unavailable
1Between 1 and 0.1 cm-1 1Default or constant
2Between 0.1 and 0.01 cm-1 2Average or estimate
3Between 0.01 and 0.001 cm-1 3> 20%
4Between 0.001 and 0.0001 cm-1 4Between 10% and 20%
5Between 0.0001 and 0.00001 cm-1 5Between 5% and 10%
6Better than 0.00001 cm-1 6Between 2% and 5%
7Between 1% and 2%
8< 1%