HC(O)OCH2D
Methyl formate, singly deuterated at methyl group
Species tag 061525
Version1*
Date of EntryAug. 2022
ContributorL. H. Coudert
H. S. P. Müller

The rotational spectrum was recorded between 770 and 1200 GHz by
(1) L. H. Coudert, B. J. Drouin, B. Tercero, J. Cernicharo, J.-C. Guillemin, R. A. Motiyenko, and L. Margulès, 2013, Astrophys. J. 779, Art. No. 119.
The analysis takes into account lower frequency data up to 655 GHz from
(2) L. Margulès, L. H. Coudert, H. Møllendal, J.-C. Guillemin, T. R. Huet, and R. Janečkovà 2009, J. Mol. Spectrosc. 254, 55.
The D atom can occupy two different positions, out of plane and in plane. The out of plane position is doubly degenerate, and tunneling leads to a symmetric and an antisymmetric tunneling component. These are indicated by state numbers 0 and 1, respectively; 2 indicates the in plane position. Very weak c-type transitions connect the two tunneling states.
The catalog entry largely corresponds to the one provided in (1). Some obvious frequency errors were corrected as were some format incompatibilities. The calculations should be sufficiently accurate for all observational purposes. Transitions with calculated uncertainties exceeding 0.1 MHz should be viewed with some caution.
The partition function from (1) refers to the ground vibrational state with J up to 80.
The dipole moment components were derived from the main species in (1).

Lines Listed58231
Frequency / GHz< 1200
Max. J80
log STR0-9.0
log STR1-7.0
Isotope Corr. 
Egy / cm–110.0; 0.0
 µa / D1.626; 1.640
 µb / D0.751; 0.724
 µc / D0.008; 0.0
 A / MHz18516.681; 19921.587
 B / MHz6730.196; 6415.267
 C / MHz5164.955; 5004.268
 Q(300.0)100582.
 Q(225.0)64705.
 Q(150.0)34489.
 Q(75.00)11474.
 Q(37.50)3619.
 Q(18.75)1047.
 Q(9.375)276.
detected in ISM/CSMyes


Database maintained by Holger S. P. Müller and Sven Thorwirth, programming by D. Roth and F. Schlöder