What's new?

And what is not quite so new anymore?

The database is described in

and in

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.

Earlier Catalog Entries

• Dec. 2024: NCCO; NC₃O; HC₄NC; HNC₅; HCCCHO.
• Nov. 2024: CH₃C(O)NH₂, v_t = 0; CH₃C(O)NH₂, v_t = 1; CH₃C(O)NH₂, v_t = 2; CH₃C(O)NH₂, Δ(v_t) > 0; NC₃³⁴S; NC₅S; NC₇S; NC₄S; NC₆S.
• Oct. 2024: CH₃CH=C=CHCN; C₂H₅C₃N; H₂C=C=CHNC; NCCS; NC₃S.
• Sep. 2024: H₂C(CCH)₂; CH₃N¹³C; ¹³CH₃NC; CH₃¹⁵NC; vinoxy; HOCS⁺; CH₃¹⁷OH, v_t = 0; CH₃¹⁷OH, v_t = 1; CH₃¹⁷OH, v_t = 0 ↔ 1.
• Aug. 2024: DC¹⁷O⁺; CH₃OD, v_t = 0; CH₃OD, v_t = 1; H₂CCO v₉ = 1; H₂CCO v₆ = 1; H₂CCO v₅ = 1.
• July 2024: HC¹⁸O⁺; HC¹⁷O⁺; DC¹⁸O⁺; corrected tags and minor mishaps for EtCP isotopologs.
• June 2024: C₂H₅CP; C₂H₅¹³CP; CH₃¹³CH₂CP; ¹³CH₃CH₂CP.
• May 2024: 3-hydroxypropenal; MgCCH; CaCCH; ²⁵MgCCH; ²⁶MgCCH; Mg¹³CCH; MgC¹³CH; cyanothioketene.
• Apr. 2024: HCCNC; DCCNC; HCCN¹³C; HC¹³CNC; H¹³CCNC; HCC¹⁵NC; DNC₃; HNCC¹³C; HNC¹³CC; HN¹³CCC; cis-HSNO; trans-HSNO.
• Feb. 2024: HNSiO; HPCO; HSiCCH; H₂C₃Si; H₂C₄Si; HCNH⁺.
• Jan. 2024: HNSO; H₂NC₃N; E-2-butenenitrile; syn-3-butenenitrile; gauche-3-butenenitrile.

• Nov. 2023: The information on the meaning of lower case characters as quantum numbers was misleading and has been rephrased. The term g_I 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.

Archive "Catalog Search Form"

• Nov. 2021: A new group was defined: Other hydrocarbons, that are hydrocarbons different from the carbon chain species C_nH and C_nH₂, but including isotopologs.

• 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.

Archive "Molecules in Space"

• Nov. 2024: added MgS, NaS, and 1-cyanopyrene with documentations.
• Oct. 2024: added 1- and 5-C₁₂H₇CN with documentation.
• Sep. 2024: added dicyanomethane and Z-1,2-dicyanoethene with documentations; updated HOCS⁺ documentation.
• Aug. 2024: added HC₃S, NC₃S, CH₂(CCH)₂, and HNC₅ with documentations; updated PO, methanol, and 3-hydroxypropenal documentations.
• July 2024: added HC₃N⁺ with documentation.
• June 2024: added 1-butyne, HC₅N⁺, and HC₇N⁺ with documentations.
• May 2024: added CaC₂, H₂CNCN, and cyanothioketene with documentations.
• Apr. 2024: added thioxyhydroxymethylium, thionylimide, and methoxyethanol with documentations; updated HCCNC, HNC₃, and HNCS documentations.
• Mar. 2024: added extragalactic protonated acetylene with documentation; updated H₂O documentation.
• Feb. 2024: added HCNS with documentation. Updated HNCS, HSCN, HNCO, and HCNO documentations.
• Jan. 2024: updated SiC₂ documentation. The 2-butenenitrile species are counted as two because mutual conversion requires breaking of a (double) bond, hence, the E- and Z-species are different isomers, not conformers.

Archive "Fitting Spectra"

• July 2024: added “Some considerations for using SPCAT”.
• May 2024: added 3-hydroxypropenal data.

Archive "Cologne Spectroscopy Data"

• July 2024: added CH₃OD and CH₃¹⁷OH files.
• June 2024: added C₂H₅CP files.
• Jan. 2024: isobutene files are complete.