National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 18October 2016
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

NIST policy on privacy, security, and accessibility.

Please rate our products
© 2013 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved.

The National Institute of Standards and Technology (NIST) is an agency of the U.S. Department of Commerce.

Please send questions, comments, corrections, additions and suggestions to

return to home page

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

Listing of experimental geometry data for C3H5 (Allyl radical)

Rotational Constants (cm-1)

See section I.F.4 to change rotational constant units
1.80189 0.34632 0.29022
Rotational Constants from 1992Hir/Yam:2963
Calculated rotational constants for C3H5 (Allyl radical).

Point Group

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 1.428 1 3 1986Vaj/Tre:4352
rCH 1.069 1 2 1986Vaj/Tre:4352 mean of all CH bonds
aCCC 124.6 3 1 4 1986Vaj/Tre:4352
aHCC 120.9 1 3 5 1986Vaj/Tre:4352 middle C - C - H
aHCC 117.7 2 1 3 1986Vaj/Tre:4352 by symmetry
picture of Allyl radical

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
H-C 5
C-C 1

Atom x (Å) y (Å) z (Å)
C1 0.0000 0.0000 0.0000
H2 0.0000 1.0690 0.0000
C3 -1.2643 -0.6638 0.0000
C4 1.2643 -0.6638 0.0000
H5 -2.1768 -0.1068 0.0000
H6 2.1768 -0.1068 0.0000
H7 -1.2643 -1.7328 0.0000
H8 1.2643 -1.7328 0.0000

Atom - Atom Distances (Å)

  C1 H2 C3 C4 H5 H6 H7 H8

Calculated geometries for C3H5 (Allyl radical).
By selecting the following links, you may be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to
squib reference DOI
1986Vaj/Tre:4352 Vajda, E., Tremmel, J., Rozsondai, B., Hargittai, I., Maltsev, A. K., Kagramanov, N. D., Nefedov, O. M., Molecular Structure of Allyl Radical from Electron Diffraction, J. Am. Chem. Soc. 108 4352-4353 10.1021/ja00275a020
1992Hir/Yam:2963 Hirota, E.; Yamada, C.; Okunishi, M. "Infrared diode alser spectroscopy of the allyl radical. The (nu)11 band." Journal of Chemical Physics. 97, 2963-2970 (1992) 10.1063/1.463037

Got a better number? Please email us at