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.3.a. (XVIII.A.3.)

Species with point groups that differ from experiment at MP2/6-31G

		Point group
Species	Name	Experimental	Calculated
HD	Deuterium hydride	C∞v	D∞h
C2H4+	Ethylene cation	D2h	D2
HCN+	hydrogen cyanide cation	C∞v	Cs
H2O2	Hydrogen peroxide	C2	C2h
MgOH	magnesium hydroxide	C∞v	Cs
CH3S	thiomethoxy	C3v	C1
C3	carbon trimer	D∞h	C2v
CH3CCH	propyne	C3v	Cs
CH3CCH	propyne	C3v	Cs
NH2CN	cyanamide	Cs	C2v
NHCHNH2	aminomethanimine	C1	Cs
BO2	Boron dioxide	D∞h	C∞v
BO2	Boron dioxide	D∞h	C∞v
HCCO	ketenyl radical	C∞v	Cs
HCNO	fulminic acid	C∞v	Cs
CaF2	Calcium difluoride	C2v	D∞h
C4	Carbon tetramer	D∞h	C2h
C4	Carbon tetramer	D∞h	C2h
C4H2	Diacetylene	D∞h	C2h
C4H2	Diacetylene	C∞v	C2h
H2CCCCH2	Butatriene	D2h	C2h
C4H6	1-Methylcyclopropene	C1	Cs
HCCCN	Cyanoacetylene	C∞v	Cs
ONNO	NO dimer	C2h	C2v
CH3COO-	acetate anion	Cs	C1
HCONHCH3	N-methylformamide	Cs	C1
CH3COCH3	Acetone	C2v	C2
C2F2	difluoroacetylene	D∞h	C2h
CF3+	Trifluoromethyl cation	D3h	C3v
SO3-	Sulfur trioxide anion	D3h	C3v
C3H5Cl	1-Propene, 3-chloro-	Cs	C1
CH2ClCH2OH2+	2-chloroethanol, protonated	C1	Cs
C5H6	3-Penten-1-yne, (Z)-	Cs	C1
C5H6	3-Penten-1-yne, (E)-	Cs	C1
C(NH2)H2CH2CH2CH3	1-Butanamine	C1	Cs
C2H6N2O	Urea, methyl-	Cs	C1
CHCl2CHO	dichloroacetaldehyde	C1	Cs
C6H4	(E)-Hexa-1,5-diyne-3-ene	C2h	C1
C6H8	(Z)-hexa-2,3,4-triene	C2v	C1
C6H10	3-Hexyne	C2v	C2
C6H14	Butane, 2,2-dimethyl-	C1	Cs
C4N2	2-Butynedinitrile	D∞h	C2h
C2H5NO3	Nitric acid, ethyl ester	C1	Cs
C5H10S	3-Ethylthio-1-propene	Cs	C1
C5H12S	Propane, 2-(ethylthio)-	Cs	C1
C6H5CHCH2	Styrene	Cs	C1
C8H14	Bicyclo[2.2.2]octane	D3h	D3
C6H12O2	Hexanoic acid	Cs	C1
C8H7N	Indole	Cs	C1
CH3COC6H5	acetophenone	C1	Cs