====== What's new? ======

[[archive|And what is not quite so new anymore?]]

The database is described in
<alert type="info">
H. S. P. Müller, F. Schlöder, J. Stutzki, and G. Winnewisser, J. Mol. Struct. 742, 215–227 (2005)
</alert>
and in
<alert type="Info">
H. S. P. Müller, S. Thorwirth, D. A. Roth, and G. Winnewisser, Astronomy and Astrophysics 370, L49–L52 (2001).
</alert>
Please acknowledge use of the CDMS by citing these article. You are very welcome to state the web
address also. We recommend to cite the original sources of the data too, which are given in the
documentations, at least as far as this is feasible.
===== Recent Catalog Entries =====

[[archive#less_recent_catalog_entries|Earlier Catalog Entries]]

  * Mar. 2026: 1H-cyclopent[cd]indene.
  * Feb. 2026: HeH<sup>+</sup>; mercaptoethanol.
  * Jan. 2026: 2-Aminopropenenitrile; //trans//-HNSO; <sup>13</sup>CH<sub>3</sub>C<sup>15</sup>N; CH<sub>3</sub><sup>13</sup>C<sup>15</sup>N; <sup>13</sup>CH<sub>3</sub><sup>13</sup>CN; methylallene.
  * Dec. 2025: NCCO<sup>+</sup>; CH<sub>2</sub>DC<sub>4</sub>H; CH<sub>3</sub>C<sub>4</sub>D; <sup>13</sup>CH<sub>3</sub>C<sub>4</sub>H; CH<sub>3</sub><sup>13</sup>CC<sub>3</sub>H; CH<sub>3</sub>C<sup>13</sup>CCCH; CH<sub>3</sub>CC<sup>13</sup>CCH; CH<sub>3</sub>C<sub>3</sub><sup>13</sup>CH.
  * Nov. 2025: 3-hydroxypropanal; //c//-S<sub>4</sub>; CH<sub>3</sub>C(O)CCH; CH<sub>3</sub>OCCH; CH<sub>3</sub>SCCH.
  * Oct. 2025: <sup>13</sup>CCS; C<sup>13</sup>CS; <sup>13</sup>C<sup>13</sup>CS; CC<sup>33</sup>S; C<sup>13</sup>C<sup>34</sup>S; C<sub>4</sub>S; C<sub>3</sub><sup>33</sup>S; C<sup>13</sup>CCS; <sup>13</sup>CCCS; C<sub>5</sub>S; <sup>13</sup>CCCCS; C<sup>13</sup>CCCS; CC<sup>13</sup>CCS; CCC<sup>13</sup>CS; C<sub>4</sub><sup>34</sup>S.
  * Sep. 2025: Phenalene; CCS; CC<sup>34</sup>S.
  * Aug. 2025: HC(O)-//c//-<sup>13</sup>CHCH<sub>2</sub>O; HC(O)-//c//-CH<sup>13</sup>CH<sub>2</sub>O; H<sup>13</sup>C(O)-//c//-CHCH<sub>2</sub>O; SiC<sub>5</sub>; SiC<sub>7</sub>; SiC<sub>8</sub>; <sup>29</sup>SiC<sub>6</sub>; <sup>30</sup>SiC<sub>6</sub>; H<sub>2</sub>NCO.
  * Jul. 2025: HC(O)-//c//-C<sub>2</sub>H<sub>3</sub>O, //v// = 0; HC(O)-//c//-C<sub>2</sub>H<sub>3</sub>O, //v//<sub>21</sub> = 1

===== General Section and General Remarks =====

  * Nov. 2023: The information on the meaning of lower case characters as quantum numbers was misleading and has been rephrased. The term //g//<sub>I</sub> was missing in several "useful equations" because it was assumed to be 1 initially. 
  * Mar. 2019: The program of the VAMDC-CDMS was updated. The Classic or ascii-CDMS was moved to this server. Links have been corrected and should work, but a detailed check is pending. The coding of special characters has been adjusted.
  * Nov. 2009: added note in the link which explains the aggregate spin number.

===== Catalog Search Form =====

[[archive#catalog_search_form|Archive "Catalog Search Form"]]

  * Nov. 2021: A new group was defined: Other hydrocarbons, that are hydrocarbons different from the carbon chain species C<sub>n</sub>H and C<sub>n</sub>H<sub>2</sub>, but including isotopologs.

===== Partition Functions =====

  * Apr. 2010: started to add values at 2.725 and 5 K for some species. The log values are also displayed in the partition function table.

===== Molecules in Space =====

[[archive#molecules_in_space|Archive "Molecules in Space"]]

  * Mar. 2026: added 2-hydroxypropanal and methoxyethanal with documentations, updated methyl acetate, hydroxypropanone, and ethyl formate documentations.
  * Feb. 2026: added propadienone and 1//H//-cyclopent[//cd//]indene with documentations; updated NH<sub>3</sub>, H<sub>3</sub>O<sup>+</sup>, CH<sub>3</sub>OH, cyclopropenone, and cyclopropenethione documentations.
  * Jan. 2026: added 3- and 4-cyanoacenaphthylene with documentations.
  * Dec. 2025: updated methylium documentation.
  * Nov. 2025: added CaS with documentation and extragalactic HCl with documentation; updated N-methylformamide, CH<sub>3</sub>C<sub>4</sub>H, and extragalactic H<sub>2</sub>Cl<sup>+</sup> documentations.
  * Oct. 2025: added C<sub>2</sub>H<sub>4</sub> documentation.
  * Sep. 2025: added (linear) SiC<sub>3</sub>, SiC<sub>5</sub>, and phenalene with documentations.
  * Aug. 2025: added SiC<sub>6</sub> with documentation; updated SiC<sub>4</sub> documentation.
  * Jul. 2025: updated HS<sub>2</sub> and methyl formate documentations.

===== Fitting Spectra =====

[[archive#fitting_spectra|Archive "Fitting Spectra"]]

  * Dec 2024: added methoxy files.
  * July 2024: added "Some considerations for using SPCAT".
  * May 2024: added 3-hydroxypropenal data.

===== Cologne Spectroscopy Data =====

[[archive#cologne_spectroscopy_data|Archive "Cologne Spectroscopy Data"]]

  * Jan. 2026: added methylallene files.
  * Dec. 2025: added NCCO<sup>+</sup> files.
  * July 2025: added oxiranecarboxaldehyde (glycidaldehyde) files.
  * Feb. 2025: added cyclopentadiene files.