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
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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 CCSD/cc-pVQZ

Species	Name	Bond type	Bond Length (Å)
			Experimental	unc.	Calculated	Difference	atom1	atom2
C2H2O2	Ethanedial	rCH	1.132		1.100	-0.032	1	3
HNO3	Nitric acid	rNO	1.406		1.378	-0.028	1	2
As4	Arsenic tetramer	rAsAs	2.435		2.410	-0.025	1	2
LiOH	lithium hydroxide	rOH	0.969		0.945	-0.024	1	3
AsH	Arsenic monohydride	rAsH	1.535	±0.001	1.513	-0.021	1	2
F2	Fluorine diatomic	rFF	1.412		1.391	-0.021	1	2
ClO	Monochlorine monoxide	rClO	1.596	±0.001	1.576	-0.020	1	2
HOBr	Hypobromous acid	rBrO	1.834		1.814	-0.020	2	3
SeO2	Selenium dioxide	rSeO	1.607	±0.001	1.588	-0.019	1	2
HSe	Selenium monohydride	rSeH	1.475	±0.010	1.458	-0.017	1	2
HF+	hydrogen fluoride cation	rHF	1.014		0.998	-0.017	1	2
H2Cl+	dihydrogen monochloride cation	rHCl	1.321	±0.000	1.304	-0.016	1	2
HeH+	Helium hydride cation	rHHe	0.790		0.775	-0.015	1	2
SeO	Selenium monoxide	rSeO	1.639	±0.001	1.625	-0.014	1	2
OCSe	Carbonyl selenide	rC=O	1.159		1.145	-0.014	1	2
B2H6	Diborane	rBH	1.200		1.186	-0.014	1	5
CH2NH	Methanimine	rCH	1.103		1.089	-0.014	1	3
C2H	Ethynyl radical	rC#C	1.217		1.203	-0.013	1	2
GeH	germylidene	rGeH	1.588		1.575	-0.013	1	2
FO	Oxygen monofluoride	rFO	1.354		1.341	-0.013	1	2
HCCl	Chloromethylene	rCH	1.119	±0.036	1.106	-0.013	1	3
HOCl	hypochlorous acid	rOH	0.973	±0.002	0.960	-0.013	1	2
NSe	Nitrogen monoselenide	rN=Se	1.652		1.639	-0.013	1	2
HOCl	hypochlorous acid	rClO	1.697	±0.001	1.685	-0.013	1	3
ArH+	Argon hydride cation	rArH	1.292	±0.000	1.280	-0.012	1	2
SeCl2	Selenium Dichloride	rClSe	2.157	±0.003	2.145	-0.012	1	2
Se2	Selenium diatomic	rSe=Se	2.166	±0.001	2.154	-0.012	1	2
H2CSe	Selenoformaldehyde	rC=Se	1.753		1.741	-0.012	1	2
SiP	Silicon monophosphide	rSiP	2.078	±0.002	2.065	-0.012	1	2
BrF	Bromine monofluoride	rFBr	1.759	±0.000	1.747	-0.012	1	2
O2+	diatomic oxygen cation	rOO	1.116		1.105	-0.011	1	2
GeO	Germanium monoxide	rOGe	1.625		1.613	-0.011	1	2
HS+	sulfur monohydride cation	rSH	1.374		1.363	-0.011	1	2
O2	Oxygen diatomic	rO=O	1.208		1.197	-0.011	1	2
CH3NH2	methyl amine	rCN	1.471	±0.003	1.460	-0.011	1	2
NO	Nitric oxide	rN=O	1.154	±0.000	1.143	-0.010	1	2
HO2	Hydroperoxy radical	rOO	1.331		1.320	-0.010	1	2
CH3CHO	Acetaldehyde	rCH	1.114		1.104	-0.010	1	4
N3	azide radical	rNN	1.181		1.171	-0.010	1	2
CH2PH	Phosphaethene	rCH	1.090	±0.015	1.080	-0.010	1	3
GaF	Gallium monofluoride	rFGa	1.774	±0.000	1.765	-0.010	1	2
PS	phosphorus sulfide	rP=S	1.900		1.891	-0.009	1	2
CH2	Methylene	rCH	1.085		1.076	-0.009	1	2
NH4+	ammonium cation	rHN	1.029	±0.000	1.020	-0.009	1	2
NO+	nitric oxide cation	rN=O	1.066		1.057	-0.009	1	2
CH3NH2	methyl amine	rNH	1.018	±0.001	1.009	-0.009	2	6
CN	Cyano radical	rC#N	1.172		1.163	-0.009	1	2
BeO	beryllium oxide	rBe=O	1.331		1.322	-0.009	1	2
GeF	Germanium monofluoride	rFGe	1.745		1.737	-0.009	1	2
CH2Br2	dibromomethane	rCBr	1.925	±0.002	1.917	-0.008	1	4
B2H6	Diborane	rBH	1.320		1.312	-0.008	1	3
CSe	Carbon monoselenide	rC=Se	1.676	±0.000	1.668	-0.008	1	2
H2CSe	Selenoformaldehyde	rHC	1.090		1.082	-0.008	1	3
HSiCl	Chlorosilylene	rSiH	1.525	±0.005	1.517	-0.008	1	3
CH2PH	Phosphaethene	rCH	1.090	±0.015	1.082	-0.008	1	4
CH3CCH	propyne	rCH	1.096		1.088	-0.008	1	5
C2H2O2	Ethanedial	rCC	1.526		1.518	-0.008	1	2
AsF	Arsenic monofluoride	rFAs	1.736	±0.001	1.728	-0.008	1	2
CH2CO	Ketene	rCH	1.083		1.075	-0.007	1	4
C2H2+	acetylene cation	rC=C	1.253	±0.001	1.245	-0.007	1	2
CF	Fluoromethylidyne	rCF	1.276		1.269	-0.007	1	2
BN	boron nitride	rB=N	1.325		1.318	-0.007	1	2
SiC	silicon monocarbide	rCSi	1.722		1.715	-0.007	1	2
H2Se	Hydrogen selenide	rSeH	1.460		1.453	-0.007	1	2
SF4	Sulfur tetrafluoride	rSF	1.646	±0.003	1.639	-0.007	1	2
HBr+	hydrogen bromide cation	rHBr	1.448		1.441	-0.007	1	2
CO+	carbon monoxide cation	rC=O	1.115	±0.000	1.108	-0.007	1	2
Br2	Bromine diatomic	rBrBr	2.281		2.275	-0.006	1	2
GeS	Germanium monosulfide	rS=Ge	2.012	±0.000	2.006	-0.006	1	2
KrH+	Protonated Krypton	rHKr	1.421	±0.000	1.415	-0.006	1	2
CH3CH2SH	ethanethiol	rCH	1.095		1.089	-0.006	1	4
CHF3	Methane, trifluoro-	rCH	1.091	±0.014	1.085	-0.006	1	2
GeF+	Germanium monofluoride cation	rFGe	1.665	±0.000	1.659	-0.006	1	2
CH2CO	Ketene	rC=O	1.162		1.156	-0.006	2	3
SCSe	Carbon sulfide selenide	rC=S	1.553	±0.002	1.547	-0.006	1	2
SCSe	Carbon sulfide selenide	rC=Se	1.695	±0.002	1.689	-0.006	1	3
GeH3F	monofluorogermane	rGeF	1.731	±0.000	1.725	-0.006	1	2
CH3Br	methyl bromide	rCBr	1.934	±0.000	1.928	-0.006	1	2
PN	Phosphorus mononitride	rP#N	1.491		1.486	-0.005	1	2
NS	Mononitrogen monosulfide	rNS	1.497	±0.000	1.492	-0.005	1	2
NH2SH	Thiohydroxylamine	rSH	1.344	±0.029	1.339	-0.005	2	3
HBr	hydrogen bromide	rHBr	1.414	±0.000	1.409	-0.005	1	2
SSO	Disulfur monoxide	rS=O	1.456		1.451	-0.005	1	2
SO+	sulfur monoxide cation	rO=S	1.424		1.419	-0.005	1	2
N2	Nitrogen diatomic	rN#N	1.098		1.093	-0.005	1	2
OPCl	Phosphorus oxychloride	rP=O	1.462	±0.011	1.458	-0.004	1	2
CN-	cyanide anion	rC#N	1.177	±0.004	1.173	-0.004	1	2
ClF	Chlorine monofluoride	rFCl	1.628	±0.000	1.624	-0.004	1	2
HNCNH	diiminomethane	rC=N	1.224	±0.001	1.220	-0.004	1	2
CH2Cl2	Methylene chloride	rCH	1.085	±0.002	1.081	-0.004	1	2
HO2	Hydroperoxy radical	rOH	0.971		0.967	-0.004	1	3
P2	Phosphorus diatomic	rP#P	1.893		1.889	-0.004	1	2
CO	Carbon monoxide	rC#O	1.128	±0.000	1.124	-0.004	1	2
SF	Monosulfur monofluoride	rSF	1.599		1.596	-0.004	1	2
BO	boron monoxide	rB=O	1.205		1.201	-0.004	1	2
H2CS	Thioformaldehyde	rC=S	1.611		1.607	-0.004	1	2
PF5	Phosphorus pentafluoride	rFP	1.577		1.574	-0.003	1	5
CH2CHF	Ethene, fluoro-	rCH	1.082		1.079	-0.003	1	4
OH-	hydroxide anion	rOH	0.964		0.961	-0.003	1	2
CH3CH2SH	ethanethiol	rCH	1.092		1.089	-0.003	1	5
BF	Boron monofluoride	rBF	1.267	±0.000	1.264	-0.003	1	2
CH3CH2SH	ethanethiol	rCH	1.090		1.087	-0.003	2	7
HF	Hydrogen fluoride	rHF	0.917	±0.000	0.914	-0.003	1	2
C3H4	cyclopropene	rCH	1.088		1.085	-0.003	1	6
SF4	Sulfur tetrafluoride	rSF	1.545	±0.003	1.542	-0.003	1	4
BrO	Bromine monoxide	rOBr	1.718		1.715	-0.003	1	2
HCCl	Chloromethylene	rCCl	1.696	±0.003	1.693	-0.003	1	2
C2H2	Acetylene	rC#C	1.203		1.200	-0.003	1	2
H2O	Water	rOH	0.958	±0.000	0.955	-0.003	1	2
OH	Hydroxyl radical	rOH	0.970		0.967	-0.002	1	2
PO	Phosphorus monoxide	rP=O	1.476		1.474	-0.002	1	2
SSO	Disulfur monoxide	rS=S	1.884		1.882	-0.002	2	3
GeH3F	monofluorogermane	rGeH	1.515	±0.000	1.512	-0.002	1	3
CH2F2	Methane, difluoro-	rCF	1.351	±0.001	1.349	-0.002	1	4
CHONH2	formamide	rNH	1.001		0.999	-0.002	3	6
SO	Sulfur monoxide	rS=O	1.481		1.479	-0.002	1	2
SiH3Cl	chlorosilane	rSiH	1.475		1.473	-0.002	1	3
SiH3F	monofluorosilane	rSiH	1.476		1.474	-0.002	1	3
CHF3	Methane, trifluoro-	rCF	1.328	±0.003	1.327	-0.002	1	3
C2H2	Acetylene	rCH	1.063		1.062	-0.001	1	3
PF2	Phosphorus difluoride	rPF	1.579		1.578	-0.001	1	2
CH	Methylidyne	rCH	1.120		1.119	-0.001	1	2
SiH4	Silane	rSiH	1.480	±0.000	1.479	-0.001	1	2
SiO	Silicon monoxide	rSiO	1.510	±0.000	1.509	-0.001	1	2
HOBr	Hypobromous acid	rOH	0.961		0.960	-0.001	1	2
BH3	boron trihydride	rBH	1.190		1.189	-0.001	1	2
CH3CHO	Acetaldehyde	rCH	1.086		1.086	0.000	2	5
CH2Cl2	Methylene chloride	rCCl	1.767	±0.002	1.767	0.000	1	4
C2	Carbon diatomic	rC=C	1.243		1.242	0.000	1	2
CH4	Methane	rCH	1.087	±0.001	1.087	0.000	1	2
BF3	Borane, trifluoro-	rBF	1.307		1.307	0.000	1	2
HCl+	hydrogen chloride cation	rHCl	1.315		1.315	0.000	1	2
BrCl	Bromine monochloride	rClBr	2.136	±0.000	2.136	0.000	1	2
CH3Br	methyl bromide	rCH	1.082	±0.001	1.082	0.000	1	3
BH	Boron monohydride	rBH	1.232		1.232	0.000	1	2
PF5	Phosphorus pentafluoride	rPF	1.534		1.534	0.000	1	2
HCl	Hydrogen chloride	rHCl	1.275	±0.000	1.275	0.000	1	2
C3H4	cyclopropene	rCH	1.072		1.072	0.000	2	4
HS	Mercapto radical	rSH	1.341		1.341	0.000	1	2
H2	Hydrogen diatomic	rHH	0.741		0.742	0.000	1	2
C2H2+	acetylene cation	rCH	1.077	±0.005	1.077	0.001	1	3
PH	phosphorus monohydride	rPH	1.422		1.423	0.001	1	2
SiS	silicon monosulfide	rSiS	1.929	±0.000	1.930	0.001	1	2
Cl2+	chlorine diatomic cation	rClCl	1.892		1.892	0.001	1	2
HS-	mercapto anion	rSH	1.343		1.344	0.001	1	2
OCSe	Carbonyl selenide	rC=Se	1.709		1.710	0.001	1	3
CHONH2	formamide	rNH	1.001		1.002	0.001	3	5
CH3CCH	propyne	rCH	1.060		1.061	0.001	3	4
SiF	silicon monofluoride	rSiF	1.604		1.606	0.001	1	2
CH3NH2	methyl amine	rCH	1.093	±0.000	1.094	0.001	1	3
CH2CHF	Ethene, fluoro-	rCH	1.077		1.078	0.001	2	5
SiH+	silicon monohydride cation	rSiH	1.504		1.506	0.001	1	2
SiH	Silylidyne	rSiH	1.520		1.522	0.002	1	2
S2	Sulfur diatomic	rS=S	1.889		1.891	0.002	1	2
SiH3F	monofluorosilane	rSiF	1.595		1.596	0.002	1	2
C2H3	vinyl	rCH	1.085		1.088	0.003	2	4
GaBr	Gallium monobromide	rGaBr	2.352	±0.000	2.355	0.003	1	2
LiNH2	lithium amide	rLiN	1.736	±0.003	1.739	0.003	1	2
CH2F2	Methane, difluoro-	rCH	1.084	±0.003	1.087	0.003	1	2
BeH	beryllium monohydride	rBeH	1.343		1.345	0.003	1	2
SiH3+	Silyl cation	rSiH	1.460	±0.010	1.463	0.003	1	2
NO-	nitric oxide anion	rN=O	1.258	±0.010	1.262	0.004	1	2
GeCl	Germanium monochloride	rClGe	2.164	±0.000	2.167	0.004	1	2
BeH2	beryllium dihydride	rBeH	1.326	±0.000	1.331	0.004	1	2
AlNC	Aluminum isocyanide	rAlN	1.855	±0.005	1.859	0.004	1	2
OPCl	Phosphorus oxychloride	rPCl	2.059	±0.004	2.063	0.005	1	3
SiF2	Silicon difluoride	rFSi	1.590	±0.000	1.595	0.005	1	2
SiH2F2	difluorosilane	rSiH	1.462		1.466	0.005	1	4
GaAs	Gallium arsenide	rGa#As	2.530	±0.020	2.535	0.005	1	2
LiOH	lithium hydroxide	rLiO	1.582		1.587	0.005	1	2
SiBr+	Silicon monobromide cation	rSiBr	2.095	±0.000	2.101	0.005	1	2
SCl2	Sulfur dichloride	rSCl	2.013	±0.001	2.019	0.006	1	2
C3O2	Carbon suboxide	rC=O	1.146		1.153	0.007	2	4
Cl2	Chlorine diatomic	rClCl	1.988		1.995	0.007	1	2
SiH3Cl	chlorosilane	rSiCl	2.051		2.058	0.007	1	2
LiO	lithium oxide	rLiO	1.688		1.696	0.008	1	2
B2	Boron diatomic	rBB	1.590		1.598	0.008	1	2
AlF	Aluminum monofluoride	rAlF	1.654	±0.000	1.662	0.008	1	2
SiCl	Clorosilylidyne	rSiCl	2.061	±0.000	2.070	0.008	1	2
LiF	lithium fluoride	rLiF	1.564	±0.000	1.573	0.009	1	2
SCl	sulfur monochloride	rSCl	1.975		1.985	0.010	1	2
NCl	nitrogen monochloride	rNCl	1.611	±0.000	1.621	0.011	1	2
MgH	magnesium monohydride	rMgH	1.730		1.741	0.011	1	2
LiH	Lithium Hydride	rLiH	1.595	±0.000	1.607	0.012	1	2
AlCl	Aluminum monochloride	rAlCl	2.130	±0.000	2.143	0.013	1	2
AlC	Aluminum carbide	rC=Al	1.955		1.968	0.013	1	2
HSiCl	Chlorosilylene	rSiCl	2.067	±0.003	2.080	0.013	1	2
AlBr	Aluminum monobromide	rAlBr	2.295		2.308	0.013	1	2
C3H5	Allyl radical	rCH	1.069		1.083	0.014	1	2
ScH	Scandium monohydride	rScH	1.775	±0.000	1.790	0.015	1	2
LiBr	Lithium Bromide	rLiBr	2.170	±0.000	2.185	0.015	1	2
C2H	Ethynyl radical	rCH	1.047		1.062	0.016	1	3
LiCl	lithium chloride	rLiCl	2.021	±0.000	2.037	0.017	1	2
C3O2	Carbon suboxide	rC=C	1.251		1.272	0.021	1	2
Li2	Lithium diatomic	rLiLi	2.673		2.698	0.025	1	2
CFCl	chlorofluoromethylene	rCCl	1.714		1.740	0.026	1	3
NaH	sodium hydride	rNaH	1.887	±0.000	1.926	0.039	1	2
NaCl	Sodium Chloride	rNaCl	2.361	±0.000	2.401	0.040	1	2
CaC	Calcium monocarbide	rC#Ca	2.302		2.348	0.046	1	2
CaH	Calcium monohydride	rCaH	2.003	±0.000	2.053	0.050	1	2
NaLi	lithium sodium	rLiNa	2.889		2.950	0.061	1	2
NaF	sodium fluoride	rNaF	1.926	±0.000	1.987	0.061	1	2
CaO	Calcium monoxide	rOCa	1.822		1.889	0.066	1	2
CaBr	Calcium monobromide	rCaBr	2.594	±0.000	2.662	0.069	1	2

204 molecules.