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Computational Chemistry Comparison and Benchmark DataBase
Release 17bSeptember 2015
NIST Standard Reference Database 101
IIExperimental data
IIICalculated data
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XOlder CCCBDB versions
XIII Vibrations
XIVReaction data
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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 C5H8 (1,3-Butadiene, 2-methyl-)

Rotational Constants (cm-1)

See section I.F.4 to change rotational constant units
0.28443 0.13928 0.09514
Rotational Constants from NISThydrocarbon
Calculated rotational constants for C5H8 (1,3-Butadiene, 2-methyl-).

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
rCC 1.340 1 2 1987Kuchitsu(II/15)
rCC 1.463 2 3 1987Kuchitsu(II/15) both C's have =
rCC 1.512 2 5 1987Kuchitsu(II/15) to methyl C
rCH 1.076 1 6 1987Kuchitsu(II/15) average, not methyl C
rCH 1.110 5 11 1987Kuchitsu(II/15) average, methyl C
aCCC 121.4 1 2 3 1987Kuchitsu(II/15) middle C has methyl C
aCCC 127.3 2 3 4 1987Kuchitsu(II/15) middle C is CH
aCCC 121 1 2 5 1987Kuchitsu(II/15) end C to methyl C
aHCC 124.3 2 1 6 1987Kuchitsu(II/15) to CH2 groups
aHCC 123.4 4 3 8 1987Kuchitsu(II/15) to CH group from end
aHCC 109.1 2 5 11 1987Kuchitsu(II/15) to CH3 group
aHCH 109.84 11 5 12 1987Kuchitsu(II/15) from symmetry, methyl group
d 73.5 1987Kuchitsu(II/15)
picture of 1,3-Butadiene, 2-methyl-

Bond descriptions

Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond
Bond Type Count
H-C 8
C-C 2
C=C 2

Atom x (Å) y (Å) z (Å)
C1 0.5485 1.7492 0.0000
C2 0.0000 0.5266 0.0000
C3 0.8273 -0.6800 0.0000
C4 0.4073 -1.9525 0.0000
C5 -1.5013 0.3467 0.0000
H6 1.6077 1.9386 0.0000
H7 -0.0142 2.6663 0.0000
H8 1.8660 -0.3990 0.0000
H9 -0.6268 -2.2497 0.0000
H10 1.0614 -2.8069 0.0000
H11 -1.9867 1.3449 0.0000
H12 -1.7995 -0.2173 0.9084
H13 -1.7995 -0.2173 -0.9084

Atom - Atom Distances (Å)

  C1 C2 C3 C4 C5 H6 H7 H8 H9 H10 H11 H12 H13

Calculated geometries for C5H8 (1,3-Butadiene, 2-methyl-).
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squib reference DOI
1987Kuchitsu(II/15) Kuchitsu (ed.), Landolt-Bornstein: Group II: Atomic and Molecular Physics Volume 15: Structure Data of Free Polyatomic Molecules. Springer-Verlag, Berlin, 1987.  
NISThydrocarbon NIST Hydrocarbon spectral database (  

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