National Institute of Standards and Technology

Computational Chemistry Comparison and Benchmark DataBase
Release 22	May 2022
NIST Standard Reference Database 101

I	Introduction
II	Experimental data
III	Calculated data
IV	Data comparisons
V	Cost comparisons
VI	Input and output files
VII	Tutorials and Units
VIII	Links to other sites
IX	Feedback
X	Older CCCBDB versions
XII	Geometries
XIII	Vibrations
XIV	Reaction data
XV	Entropy data
XVI	Bibliographic data
XVII	Ion data
XVIII	Bad calculations
XIX	Index of properties
XX	H-bond dimers
XXI	Oddities

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IV.D.4. (XII.A.2.)

Compare Experimental Geometries - experimental data

Species	Name
C3H2N2	Malononitrile

The following table lists the experimentally determined internal coordinates. Coordinate descriptions starting with "r" are bond lengths, starting with "a" are bond angles, and starting with "d" are dihedral angles. Atom numbers are the numbers on the picture of the molecule below to indicate which atoms are invloved in the bond or angle.
Units: bond lengths are in Å, angles are in degrees.

description	Value	Reference	Comment	Atom number
rCC	1.459	1990Ran/Cox:1981	average structure	1	2
rCN	1.160	1990Ran/Cox:1981		2	6
rCH	1.109	1990Ran/Cox:1981		1	4
aCCN	178.6			1	2	6
aCCC	112.5	1990Ran/Cox:1981		2	1	3
aHCH	106.9	1990Ran/Cox:1981		4	1	5
aHCC	109.3	1990Ran/Cox:1981	by symmetry	2	1	4

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References

squib	reference
1990Ran/Cox:1981	J Randell, AP Cox, I Merke, H Dreizler, "Dicyanomethane: Microwave spectrum, Quadrupole Coupling and Sturcture" J. Chem. Soc. Farad. Trans. 1990, 86(11), 1981-1989