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 CH3CCCH3 (2-Butyne)

Rotational Constants (cm-1)

See section I.F.4 to change rotational constant units
2.55797 0.11065 0.11065
Rotational Constants from 1976Hellwege(II/7)
Calculated rotational constants for CH3CCCH3 (2-Butyne).

Point Group D3h

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
rCH 1.116 3 5 1976Hellwege(II/7)
rCC 1.468 1 3 1976Hellwege(II/7)
rCC 1.214 1 2 1976Hellwege(II/7)
aHCC 110.7 1 3 5 1976Hellwege(II/7)
aHCH 108.21 1 3 5 1976Hellwege(II/7) by symmetry
picture of 2-Butyne

Bond descriptions

Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond
Bond Type Count
H-C 6
C-C 2
C#C 1

Atom x (Å) y (Å) z (Å)
C1 0.0000 0.0000 0.6070
C2 0.0000 0.0000 -0.6070
C3 0.0000 0.0000 2.0750
C4 0.0000 0.0000 -2.0750
H5 0.0000 1.0440 2.4695
H6 -0.9041 -0.5220 2.4695
H7 0.9041 -0.5220 2.4695
H8 0.0000 1.0440 -2.4695
H9 0.9041 -0.5220 -2.4695
H10 -0.9041 -0.5220 -2.4695

Atom - Atom Distances (Å)

  C1 C2 C3 C4 H5 H6 H7 H8 H9 H10

Calculated geometries for CH3CCCH3 (2-Butyne).
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squib reference DOI
1976Hellwege(II/7) Hellwege, KH and AM Hellwege (ed.). Landolt-Bornstein: Group II: Atomic and Molecular Physics Volume 7: Structure Data of Free Polyatomic Molecules. Springer-Verlag. Berlin. 1976.  

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