The HITEMP2010 database is described in the article "HITEMP, the high-temperature molecular spectroscopic database" (2010) . This edition replaced the earlier version, "HITRAN, HAWKS and HITEMP: High-Temperature Molecular Database" (1995) .
HITEMP is currently undergoing a major expansion. The current HITEMP data can be downloaded by clicking the corresponding download icon () and selecting the appropriate file (if applicable). Further information, a readme, and a python script to extract bzip2 compressed files are provided below the table.
|ID||Formula||Name||Iso counta||Line countb||νmin/cm-1||νmax/cm-1||Year||Download|
|1||H2O||Water||6||114 241 164||0||30 000||2010|
|2||CO2||Carbon Dioxide||7||11 193 608||258||9 648||2010||4||N2O||Nitrous Oxide||5||3 626 425||0||12 899||2019|
|5||CO||Carbon Monoxide||6||752 976||2||22 149||2019|
|6||CH4||Methane||4||31 880 412||0||13 400||2020|
|8||NO||Nitric Oxide||3||1 137 192||0||26 777||2019|
|10||NO2||Nitrogen Dioxide||1||1 108 709||0||4 775||2019|
|13||OH||Hydroxyl Radical||3||57 019||0||43 409||2020|
|a Number of isotopologues included in HITEMP
b Total line count for molecule including its isotopologues
The extracted format for each line transition file of HITEMP is consistent with the ".par" fixed-length HITRAN format (i.e., 160 characters per transition) and is described in Ref. . The data highlighted in bold is a new addition or has superseded the previous HITEMP2010 data. Due to the very large number of lines for H2O and CO2, the line transition files have been partitioned by wavenumber interval and compressed. A readme is provided for further details (but more dynamic solutions will be available soon):
The major expansion of HITEMP includes the addition of new molecules [3,4] and updates to the data for molecules that constituted the HITEMP2010 article . At present, the HITEMP database includes seven molecules which are summarized in the table above. Molecules that have been added/updated since the HITRAN2010 article are indicated in bold, with additional details provided in the appropriate articles [3,4,5]. In addition to the eight molecules above, the line-by-line HITRAN data for HF, HCl, HBr, HI, and H2 (molecule ID 14, 15, 16, 17, and 45) are also suitable for high temperature applications and can be accessed on the line-by-line page.
The updated HITEMP files are provided in the compressed bzip2 format and can be extracted using the following python tool:
To extract a portion of the HITEMP file into the ".par" format, use the following command:
python hitemp_bz2_extract.py <filename.par.bz2> <numin> <numax>
Where <numin> and <numax> refer to the minimum and maximum wavenumber required. These can be excluded to extract the complete spectral range.
We advise users to download the most up-to-date version of HITEMP data from the table above. However, the HITEMP2010 data  will remain accessible directly from the HITEMP server, even after the latest updates have been applied. In the HITEMP-2010 directory you will find "Read-me_for_HITEMP.pdf" along with five folders corresponding to H2O, CO2, CO, NO and OH.
When using the HITEMP database, please cite the appropriate HITEMP article (e.g., ) as well as the original sources of data. To assist the user, each line transition has reference codes that are provided for each parameter and are consistent with those in HITRAN for the same molecule. We hope that you will find HITEMP helpful in your research.
 L. S. Rothman, I. E. Gordon, R. J. Barber, H. Dothe, R. R. Gamache, A. Goldman, V. Perevalov, S. A. Tashkun, J. Tennyson, "HITEMP, the high-temperature molecular spectroscopic database", J. Quant. Spectrosc. Radiat. Transfer 111, 2139-2150 (2010).
 L. S. Rothman, R. B. Wattson, R. R. Gamache, J. Schroeder, A. McCann, "HITRAN, HAWKS and HITEMP: High-Temperature Molecular Database", Proc. SPIE, Atmospheric Propogation and Remote Sensing IV 2471, 105-111 (1995).
 R. J. Hargreaves, I. E. Gordon, L. S. Rothman, S. A. Tashkun, V. I. Perevalov, S. N. Yurchenko, J. Tennyson, H. S. P. Müller, "Spectroscopic line parameters of NO, NO2, and N2O for the HITEMP database", J. Quant. Spectrosc. Radiat. Transfer 232, 35-53 (2019).
 R. J. Hargreaves, I. E. Gordon, M. Rey, A. V. Nikitin, V. G. Tyuterev, R. V. Kochanov, L. S. Rothman, "An accurate, extensive, and practical line list of methane for the HITEMP database", Astrophys. J. Supp. Ser. 247, 55 (2020).
 G. Li, I. E. Gordon, L. S. Rothman, Y. Tan, S.-M. Hu, S. Kassi, A. Campargue, E. S. Medvedev, "Rovibrational line lists for nine isotopologues of the CO molecule in the X1Σ+ ground electronic state", Astrophys. J. Supp. Ser. 216, 15 (2015).