return to home page

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

Listing of experimental geometry data for C5H8 (Spiropentane)

Rotational Constants (cm-1)
See section I.F.4 to change rotational constant units
Rotational Constants from
Calculated rotational constants for C5H8 (Spiropentane).

Point Group D2d

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 1.520 2 3 1976Hellwege(II/7)
rCC 1.470 1 2 1976Hellwege(II/7) from center
rCH 1.090 2 6 1976Hellwege(II/7)
aCCC 62 2 1 3 1976Hellwege(II/7) center C is center C
aHCH 118 6 2 7 1976Hellwege(II/7)
aCCC 59 1 2 3 symmetry
aCCC 137.3 2 1 4 by symmetry
picture of Spiropentane

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 6

Atom x (Å) y (Å) z (Å)
C1 0.0000 0.0000 0.0000

Atom - Atom Distances (Å)

Calculated geometries for C5H8 (Spiropentane).

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
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.  

Got a better number? Please email us at