National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 19April 2018
NIST Standard Reference Database 101
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
VIInput and output files
VIITutorials and Units
VIIILinks to other sites
XOlder CCCBDB versions
XIII Vibrations
XIVReaction data
XVEntropy data
XVIBibliographic data
XVIIIon data
XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers

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II.A.3. (XII.A.1.)

Listing of experimental geometry data for C3H4O (Methylketene)

Rotational Constants (cm-1)

See section I.F.4 to change rotational constant units
1.29823 0.15035 0.13799
Rotational Constants from 1966Bak/Chr:883
Calculated rotational constants for C3H4O (Methylketene).

Point Group Cs

Internal coordinates

(distances (r) in Å) (angles (a) in degrees) (dihedrals (d) in degrees)
Description Value Connectivity Reference Comment
Atom 1 Atom 2 Atom 3 Atom 4
rCO 1.171 1 4 1966Bak/Chr:883
rCC 1.306 1 2 1966Bak/Chr:883
rCC 1.518 2 3 1966Bak/Chr:883
rCH 1.083 2 5 1966Bak/Chr:883 vinyl
rCH 1.083 3 6 1966Bak/Chr:883 methyl
aCCO 180 2 1 4 1966Bak/Chr:883
aCCC 122.6 1 2 3 1966Bak/Chr:883
aHCC 113.7 1 2 5 1966Bak/Chr:883
aHCH 109.9 6 3 7 1966Bak/Chr:883
picture of Methylketene

Bond descriptions

Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond
Bond Type Count
C-C 1
C=C 1
C=O 1
H-C 4

Atom x (Å) y (Å) z (Å)

Atom - Atom Distances (Å)


Calculated geometries for C3H4O (Methylketene).
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squib reference DOI
1966Bak/Chr:883 B Bak, JJ Christiansen, K Kuntsmann, L Nygaard, J Rastrup-Andersen "Microwave Spectrum, Molecular Structure, Barrier to Internal Rotation, and Dipole Moment of Methylketene" J. Chem. Phys. 45(1), 883, 1966 10.1063/1.1727700

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