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.8.

Average Bond Length Differences by Model Chemistry

Calculated at ROHF/cc-pVDZ

Species	Name	Bond type	Bond Length (Å)
			Experimental	unc.	Calculated	Difference	atom1	atom2
BeCl	beryllium monochloride	rBeCl	1.797		1.659	-0.138	1	2
CaC	Calcium monocarbide	rC#Ca	2.302		2.205	-0.096	1	2
O2	Oxygen diatomic	rO=O	1.208		1.154	-0.053	1	2
O2+	diatomic oxygen cation	rOO	1.116		1.064	-0.053	1	2
NO	Nitric oxide	rN=O	1.154	±0.000	1.119	-0.035	1	2
BN	boron nitride	rB=N	1.325		1.292	-0.033	1	2
CN	Cyano radical	rC#N	1.172		1.139	-0.033	1	2
SeO	Selenium monoxide	rSeO	1.639	±0.001	1.607	-0.032	1	2
FO	Oxygen monofluoride	rFO	1.354		1.322	-0.032	1	2
C2H2O2	Ethanedial	rCH	1.132		1.100	-0.032	1	3
CO+	carbon monoxide cation	rC=O	1.115	±0.000	1.084	-0.032	1	2
N3	azide radical	rNN	1.181		1.150	-0.031	1	2
SiC	silicon monocarbide	rCSi	1.722		1.693	-0.029	1	2
CP	Carbon monophosphide	rC#P	1.562		1.533	-0.029	1	2
HF+	hydrogen fluoride cation	rHF	1.014		0.987	-0.027	1	2
C2H	Ethynyl radical	rC#C	1.217		1.191	-0.026	1	2
SO+	sulfur monoxide cation	rO=S	1.424		1.399	-0.025	1	2
Se2	Selenium diatomic	rSe=Se	2.166	±0.001	2.142	-0.024	1	2
HO2	Hydroperoxy radical	rOO	1.331		1.307	-0.024	1	2
CH3OCl	methyl hypochlorite	rCH	1.111	±0.018	1.089	-0.022	3	4
SiN	Silicon nitride	rSiN	1.575		1.554	-0.021	1	2
BO	boron monoxide	rB=O	1.205		1.184	-0.021	1	2
NSe	Nitrogen monoselenide	rN=Se	1.652		1.632	-0.020	1	2
COBr2	Carbonic dibromide	rC=O	1.172	±0.003	1.152	-0.019	1	2
NF	nitrogen fluoride	rNF	1.317		1.298	-0.019	1	2
HO2	Hydroperoxy radical	rOH	0.971		0.952	-0.019	1	3
He2+	helium diatomic cation	rHeHe	1.081	±0.001	1.063	-0.018	1	2
SiP	Silicon monophosphide	rSiP	2.078	±0.002	2.060	-0.018	1	2
C2H2+	acetylene cation	rC=C	1.253	±0.001	1.235	-0.018	1	2
H2Cl+	dihydrogen monochloride cation	rHCl	1.321	±0.000	1.303	-0.017	1	2
NO-	nitric oxide anion	rN=O	1.258	±0.010	1.242	-0.016	1	2
HS+	sulfur monohydride cation	rSH	1.374		1.360	-0.014	1	2
HSe	Selenium monohydride	rSeH	1.475	±0.010	1.462	-0.013	1	2
AsH	Arsenic monohydride	rAsH	1.535	±0.001	1.521	-0.013	1	2
DO	Hydroxyl-d	rDO	0.970		0.957	-0.013	1	2
OH	Hydroxyl radical	rOH	0.970		0.957	-0.012	1	2
SO	Sulfur monoxide	rS=O	1.481		1.470	-0.011	1	2
CF	Fluoromethylidyne	rCF	1.276		1.266	-0.010	1	2
C2H2O2	Ethanedial	rCC	1.526		1.516	-0.010	1	2
NS	Mononitrogen monosulfide	rNS	1.497	±0.000	1.487	-0.010	1	2
HBr+	hydrogen bromide cation	rHBr	1.448		1.441	-0.008	1	2
PS	phosphorus sulfide	rP=S	1.900		1.892	-0.008	1	2
NH	Imidogen	rNH	1.036		1.029	-0.007	1	2
HeH+	Helium hydride cation	rHHe	0.790		0.784	-0.006	1	2
PO	Phosphorus monoxide	rP=O	1.476		1.470	-0.006	1	2
Cl2+	chlorine diatomic cation	rClCl	1.892		1.886	-0.006	1	2
AlS	Aluminum sulfide	rAlS	2.029		2.024	-0.005	1	2
CBrClF2	Methane, bromochlorodifluoro-	rCBr	1.932	±0.004	1.927	-0.005	1	2
S2	Sulfur diatomic	rS=S	1.889		1.886	-0.004	1	2
CH2	Methylene	rCH	1.085		1.081	-0.004	1	2
CH3CH2SH	ethanethiol	rCH	1.095		1.092	-0.003	1	4
HBr	hydrogen bromide	rHBr	1.414	±0.000	1.412	-0.002	1	2
CH	Methylidyne	rCH	1.120		1.118	-0.002	1	2
H2Se	Hydrogen selenide	rSeH	1.460		1.458	-0.002	1	2
CH2CHF	Ethene, fluoro-	rCH	1.082		1.081	-0.001	1	4
HCl+	hydrogen chloride cation	rHCl	1.315		1.313	-0.001	1	2
ClF	Chlorine monofluoride	rFCl	1.628	±0.000	1.627	-0.001	1	2
CBr4	Carbon tetrabromide	rCBr	1.942	±0.002	1.941	-0.001	1	2
CH3CH2SH	ethanethiol	rCH	1.090		1.089	-0.001	2	7
CH3CH2SH	ethanethiol	rCH	1.092		1.092	0.000	1	5
BS	boron sulfide	rBS	1.609		1.609	0.000	1	2
CH3Br	methyl bromide	rCH	1.082	±0.001	1.085	0.002	1	3
C2H3	vinyl	rCH	1.085		1.087	0.002	2	4
C2H2+	acetylene cation	rCH	1.077	±0.005	1.079	0.002	1	3
HS	Mercapto radical	rSH	1.341		1.344	0.003	1	2
DS	Mercapto-d	rSD	1.341		1.344	0.003	1	2
MgH	magnesium monohydride	rMgH	1.730		1.733	0.003	1	2
GeH	germylidene	rGeH	1.588		1.592	0.004	1	2
PH	phosphorus monohydride	rPH	1.422		1.427	0.004	1	2
CH2CHF	Ethene, fluoro-	rCH	1.077		1.081	0.004	2	5
CH3OCl	methyl hypochlorite	rCH	1.086	±0.018	1.090	0.004	3	5
SiH3+	Silyl cation	rSiH	1.460	±0.010	1.466	0.006	1	2
CH3CH2O	Ethoxy radical	rCH	1.085		1.092	0.007	1	5
CH3CH2O	Ethoxy radical	rCH	1.086		1.093	0.007	1	4
GaF	Gallium monofluoride	rFGa	1.774	±0.000	1.782	0.007	1	2
BeH	beryllium monohydride	rBeH	1.343		1.350	0.008	1	2
CH3CH2O	Ethoxy radical	rCH	1.088		1.096	0.008	2	7
SiH	Silylidyne	rSiH	1.520		1.529	0.008	1	2
HS-	mercapto anion	rSH	1.343		1.354	0.011	1	2
CH3Br	methyl bromide	rCBr	1.934	±0.000	1.946	0.012	1	2
AsF	Arsenic monofluoride	rFAs	1.736	±0.001	1.750	0.014	1	2
GeF	Germanium monofluoride	rFGe	1.745		1.761	0.015	1	2
C3H5	Allyl radical	rCH	1.069		1.085	0.016	1	2
LiO	lithium oxide	rLiO	1.688		1.706	0.017	1	2
C2H	Ethynyl radical	rCH	1.047		1.064	0.018	1	3
SF	Monosulfur monofluoride	rSF	1.599		1.618	0.018	1	2
SiBr+	Silicon monobromide cation	rSiBr	2.095	±0.000	2.122	0.027	1	2
PF2	Phosphorus difluoride	rPF	1.579		1.611	0.032	1	2
PF	phosphorus monofluoride	rFP	1.593		1.628	0.036	1	2
CCl	carbon monochloride	rCCl	1.649		1.685	0.036	1	2
BeF	Beryllium monofluoride	rBeF	1.361		1.399	0.038	1	2
ClO	Monochlorine monoxide	rClO	1.596	±0.001	1.634	0.038	1	2
AlC	Aluminum carbide	rC=Al	1.955		1.997	0.042	1	2
SCl	sulfur monochloride	rSCl	1.975		2.019	0.044	1	2
SiF2	Silicon difluoride	rFSi	1.590	±0.000	1.634	0.044	1	2
SiF	silicon monofluoride	rSiF	1.604		1.649	0.045	1	2
GeCl	Germanium monochloride	rClGe	2.164	±0.000	2.209	0.045	1	2
CaH	Calcium monohydride	rCaH	2.003	±0.000	2.053	0.050	1	2
SiCl	Clorosilylidyne	rSiCl	2.061	±0.000	2.114	0.052	1	2
GaAs	Gallium arsenide	rGa#As	2.530	±0.020	2.584	0.054	1	2
B2	Boron diatomic	rBB	1.590		1.650	0.060	1	2
TiCl	Titanium Monochloride	rClTi	2.265	±0.000	2.329	0.065	1	2
BrO	Bromine monoxide	rOBr	1.718		1.783	0.066	1	2
NCl	nitrogen monochloride	rNCl	1.611	±0.000	1.677	0.066	1	2
AlN	Aluminum nitride	rN#Al	1.786		1.853	0.066	1	2
CrH	Chromium hydride	rHCr	1.655	±0.001	1.727	0.072	1	2
CaBr	Calcium monobromide	rCaBr	2.594	±0.000	2.684	0.090	1	2
AlO	Aluminum monoxide	rAlO	1.618		1.738	0.120	1	2

108 molecules.