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Version 2026.02
Tag 61803
Molecule - Descriptor Methyl Formate (HCOO13CH3) - 13C2 : vt=0
Isotope 13C
Hyperfine N/A
Lines in DB 37262
Frequency max. (MHz) 2188601.678
J max. 79
Cite these data as Haykal I., Carvajal M., Tercero B., Kleiner I., López A., Cernicharo J., Motiyenko R.A., Huet T.R., Guillemin J.C., Margulès L. 2014, A&A, 568, A58 https://doi.org/10.1051/0004-6361/201322937
Predictions Partition Function Quantum Numbers Format References

The partition function values are taken from Favre et al. (2014), ApJS, 215, 25. These correspond to the total rotation–torsion–vibrational partition function.

Since LSD stores rotational and vibrational contributions to the partition function separately, the full partition function reported by Favre et al. is assigned here to Qrot, while Qvib is set to 1.

T(K) Qt Qrot Qvib
300.0 255988.580 255988.58 1.0
225.0 106847.860 106847.86 1.0
150.0 37442.270 37442.27 1.0
75.0 9162.120 9162.12 1.0
37.5 2971.200 2971.2 1.0
18.75 1045.220 1045.22 1.0
9.375 370.950 370.95 1.0

Energy levels of an asymmetric top with a single internal rotor of C3v symmetry

Code:
BELGI-Cs
Format:
J Ka Kc m

Details: Each energy level is characterized by the asymmetric-top quantum numbers J, Ka, and Kc, together with the free-rotor quantum number m. When table includes hyperfine levels, the standard quantum number F = J + I is included in the level designation.

The correspondence between the m quantum number used in the .cat file and the vibrational–torsional quantum number vt, as well as the associated symmetry species Γ = A or E of the C3v point group, is summarized in the table below.

m 0 1 -3 -2 3 4 -6 -5 6 7
vt 0 0 1 1 2 2 3 3 4 4
Γ A E A E A E A E A E
Measurements

  • Carvajal M., Margulès L., Tercero B., Demyk K., Kleiner I., Guillemin J.C., Lattanzi V., Walters A., Demaison J., Wlodarczak G., et al. 2009, A&A, 500, 1109–1118
Dipole moments