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
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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 CCSD(T)/cc-pVQZ

Species	Name	Bond type	Bond Length (Å)
			Experimental	unc.	Calculated	Difference	atom1	atom2
C2H2O2	Ethanedial	rCH	1.132		1.102	-0.030	1	3
CH3CH2CH2CH3	Butane	rCH	1.117		1.095	-0.022	1	5
LiOH	lithium hydroxide	rOH	0.969		0.948	-0.021	1	3
AsH	Arsenic monohydride	rAsH	1.535	±0.001	1.516	-0.019	1	2
HeH+	Helium hydride cation	rHHe	0.790		0.775	-0.015	1	2
HSe	Selenium monohydride	rSeH	1.475	±0.010	1.460	-0.015	1	2
ClO	Monochlorine monoxide	rClO	1.596	±0.001	1.582	-0.014	1	2
HF+	hydrogen fluoride cation	rHF	1.014		1.000	-0.014	1	2
H2Cl+	dihydrogen monochloride cation	rHCl	1.321	±0.000	1.307	-0.014	1	2
B2H6	Diborane	rBH	1.200		1.187	-0.013	1	5
As4	Arsenic tetramer	rAsAs	2.435		2.423	-0.012	1	2
CH2NH	Methanimine	rCH	1.103		1.091	-0.012	1	3
GeH	germylidene	rGeH	1.588		1.576	-0.012	1	2
ArH+	Argon hydride cation	rArH	1.292	±0.000	1.282	-0.010	1	2
HCCl	Chloromethylene	rCH	1.119	±0.036	1.109	-0.010	1	3
HOCl	hypochlorous acid	rOH	0.973	±0.002	0.964	-0.009	1	2
C2H	Ethynyl radical	rC#C	1.217		1.208	-0.008	1	2
HS+	sulfur monohydride cation	rSH	1.374		1.366	-0.008	1	2
CH2	Methylene	rCH	1.085		1.077	-0.008	1	2
CH2PH	Phosphaethene	rCH	1.090	±0.015	1.083	-0.007	1	3
NH4+	ammonium cation	rHN	1.029	±0.000	1.021	-0.007	1	2
C2H2O2	Ethanedial	rCC	1.526		1.519	-0.007	1	2
B2H6	Diborane	rBH	1.320		1.313	-0.007	1	3
HNO3	Nitric acid	rNO	1.406		1.399	-0.007	1	2
H2CSe	Selenoformaldehyde	rHC	1.090		1.084	-0.006	1	3
CH3NH2	methyl amine	rNH	1.018	±0.001	1.012	-0.006	2	6
CH3CCH	propyne	rCH	1.096		1.090	-0.006	1	5
CH3NH2	methyl amine	rCN	1.471	±0.003	1.465	-0.006	1	2
HOBr	Hypobromous acid	rBrO	1.834		1.828	-0.006	2	3
CH2PH	Phosphaethene	rCH	1.090	±0.015	1.084	-0.006	1	4
CH2CO	Ketene	rCH	1.083		1.077	-0.006	1	4
SeCl2	Selenium Dichloride	rClSe	2.157	±0.003	2.151	-0.006	1	2
HSiCl	Chlorosilylene	rSiH	1.525	±0.005	1.520	-0.005	1	3
CH3CH2CH2CH3	Butane	rCC	1.531		1.526	-0.005	1	2
H2Se	Hydrogen selenide	rSeH	1.460		1.455	-0.005	1	2
GaF	Gallium monofluoride	rFGa	1.774	±0.000	1.770	-0.005	1	2
CHF3	Methane, trifluoro-	rCH	1.091	±0.014	1.087	-0.004	1	2
CH3CH2SH	ethanethiol	rCH	1.095		1.091	-0.004	1	4
HBr+	hydrogen bromide cation	rHBr	1.448		1.444	-0.004	1	2
NO	Nitric oxide	rN=O	1.154	±0.000	1.150	-0.004	1	2
KrH+	Protonated Krypton	rHKr	1.421	±0.000	1.418	-0.004	1	2
OCSe	Carbonyl selenide	rC=O	1.159		1.156	-0.003	1	2
GeF	Germanium monofluoride	rFGe	1.745		1.742	-0.003	1	2
HBr	hydrogen bromide	rHBr	1.414	±0.000	1.411	-0.003	1	2
CH2Br2	dibromomethane	rCBr	1.925	±0.002	1.922	-0.003	1	4
NH2SH	Thiohydroxylamine	rSH	1.344	±0.029	1.342	-0.002	2	3
CH2Cl2	Methylene chloride	rCH	1.085	±0.002	1.083	-0.002	1	2
FO	Oxygen monofluoride	rFO	1.354		1.352	-0.002	1	2
C2H2+	acetylene cation	rC=C	1.253	±0.001	1.251	-0.002	1	2
N3	azide radical	rNN	1.181		1.180	-0.002	1	2
CH3CH2SH	ethanethiol	rCH	1.092		1.091	-0.001	1	5
GeH3F	monofluorogermane	rGeF	1.731	±0.000	1.730	-0.001	1	2
CF	Fluoromethylidyne	rCF	1.276		1.275	-0.001	1	2
C3H4	cyclopropene	rCH	1.088		1.087	-0.001	1	6
SeO	Selenium monoxide	rSeO	1.639	±0.001	1.638	-0.001	1	2
DF	Hydrofluoric acid-d	rDF	0.917	±0.000	0.916	-0.001	1	2
AsF	Arsenic monofluoride	rFAs	1.736	±0.001	1.735	-0.001	1	2
SeO2	Selenium dioxide	rSeO	1.607	±0.001	1.606	-0.001	1	2
CH2CHF	Ethene, fluoro-	rCH	1.082		1.081	-0.001	1	4
H2CSe	Selenoformaldehyde	rC=Se	1.753		1.752	-0.001	1	2
CH3CH2SH	ethanethiol	rCH	1.090		1.089	-0.001	2	7
SiP	Silicon monophosphide	rSiP	2.078	±0.002	2.077	-0.001	1	2
GeH3F	monofluorogermane	rGeH	1.515	±0.000	1.514	-0.001	1	3
He2+	helium diatomic cation	rHeHe	1.081	±0.001	1.080	-0.001	1	2
CO+	carbon monoxide cation	rC=O	1.115	±0.000	1.115	-0.001	1	2
HF	Hydrogen fluoride	rHF	0.917	±0.000	0.916	-0.001	1	2
SiH3F	monofluorosilane	rSiH	1.476		1.476	-0.001	1	3
SiC	silicon monocarbide	rCSi	1.722		1.721	-0.001	1	2
CH3Br	methyl bromide	rCBr	1.934	±0.000	1.933	-0.001	1	2
HO2	Hydroperoxy radical	rOO	1.331		1.330	0.000	1	2
HO2	Hydroperoxy radical	rOH	0.971		0.970	0.000	1	3
NO+	nitric oxide cation	rN=O	1.066		1.065	0.000	1	2
SiH3Cl	chlorosilane	rSiH	1.475		1.475	0.000	1	3
BrF	Bromine monofluoride	rFBr	1.759	±0.000	1.759	0.000	1	2
BH3	boron trihydride	rBH	1.190		1.190	0.000	1	2
SiH4	Silane	rSiH	1.480	±0.000	1.480	0.000	1	2
H2O	Water	rOH	0.958	±0.000	0.958	0.000	1	2
OH-	hydroxide anion	rOH	0.964		0.964	0.000	1	2
C2H2	Acetylene	rCH	1.063		1.063	0.000	1	3
PS	phosphorus sulfide	rP=S	1.900		1.900	0.000	1	2
OH	Hydroxyl radical	rOH	0.970		0.970	0.000	1	2
CH	Methylidyne	rCH	1.120		1.120	0.000	1	2
H2	Hydrogen diatomic	rHH	0.741		0.742	0.000	1	2
GeF+	Germanium monofluoride cation	rFGe	1.665	±0.000	1.666	0.000	1	2
O2	Oxygen diatomic	rO=O	1.208		1.208	0.000	1	2
O2+	diatomic oxygen cation	rOO	1.116		1.117	0.001	1	2
BF	Boron monofluoride	rBF	1.267	±0.000	1.267	0.001	1	2
CHONH2	formamide	rNH	1.001		1.002	0.001	3	6
CH4	Methane	rCH	1.087	±0.001	1.088	0.001	1	2
NSe	Nitrogen monoselenide	rN=Se	1.652		1.653	0.001	1	2
BH	Boron monohydride	rBH	1.232		1.233	0.001	1	2
F2	Fluorine diatomic	rFF	1.412		1.413	0.001	1	2
CH2CO	Ketene	rC=O	1.162		1.163	0.001	2	3
Se2	Selenium diatomic	rSe=Se	2.166	±0.001	2.167	0.001	1	2
SCSe	Carbon sulfide selenide	rC=Se	1.695	±0.002	1.696	0.001	1	3
CH3Br	methyl bromide	rCH	1.082	±0.001	1.084	0.002	1	3
HOCl	hypochlorous acid	rClO	1.697	±0.001	1.699	0.002	1	3
GaBr	Gallium monobromide	rGaBr	2.352	±0.000	2.354	0.002	1	2
OCSe	Carbonyl selenide	rC=Se	1.709		1.711	0.002	1	3
HCCl	Chloromethylene	rCCl	1.696	±0.003	1.698	0.002	1	2
HCl	Hydrogen chloride	rHCl	1.275	±0.000	1.277	0.002	1	2
C2H2+	acetylene cation	rCH	1.077	±0.005	1.079	0.002	1	3
HNCNH	diiminomethane	rC=N	1.224	±0.001	1.226	0.002	1	2
HCl+	hydrogen chloride cation	rHCl	1.315		1.317	0.002	1	2
HS	Mercapto radical	rSH	1.341		1.343	0.002	1	2
C3H4	cyclopropene	rCH	1.072		1.074	0.002	2	4
Br2	Bromine diatomic	rBrBr	2.281		2.283	0.002	1	2
N2	Nitrogen diatomic	rN#N	1.098		1.100	0.003	1	2
BrO	Bromine monoxide	rOBr	1.718		1.720	0.003	1	2
HOBr	Hypobromous acid	rOH	0.961		0.964	0.003	1	2
CH3NH2	methyl amine	rCH	1.093	±0.000	1.096	0.003	1	3
CH3CCH	propyne	rCH	1.060		1.063	0.003	3	4
GeO	Germanium monoxide	rOGe	1.625		1.628	0.003	1	2
CH2CHF	Ethene, fluoro-	rCH	1.077		1.080	0.003	2	5
PH	phosphorus monohydride	rPH	1.422		1.425	0.003	1	2
CN-	cyanide anion	rC#N	1.177	±0.004	1.180	0.003	1	2
SiH+	silicon monohydride cation	rSiH	1.504		1.507	0.003	1	2
BN	boron nitride	rB=N	1.325		1.328	0.003	1	2
CO	Carbon monoxide	rC#O	1.128	±0.000	1.131	0.003	1	2
HS-	mercapto anion	rSH	1.343		1.346	0.003	1	2
BeH	beryllium monohydride	rBeH	1.343		1.346	0.003	1	2
C2	Carbon diatomic	rC=C	1.243		1.246	0.003	1	2
CH2F2	Methane, difluoro-	rCF	1.351	±0.001	1.354	0.003	1	4
CHONH2	formamide	rNH	1.001		1.004	0.003	3	5
BF3	Borane, trifluoro-	rBF	1.307		1.310	0.003	1	2
SCSe	Carbon sulfide selenide	rC=S	1.553	±0.002	1.557	0.004	1	2
CHF3	Methane, trifluoro-	rCF	1.328	±0.003	1.332	0.004	1	3
BO	boron monoxide	rB=O	1.205		1.208	0.004	1	2
SiH	Silylidyne	rSiH	1.520		1.524	0.004	1	2
B2	Boron diatomic	rBB	1.590		1.594	0.004	1	2
C2H2	Acetylene	rC#C	1.203		1.207	0.004	1	2
CH2Cl2	Methylene chloride	rCCl	1.767	±0.002	1.771	0.004	1	4
BeH2	beryllium dihydride	rBeH	1.326	±0.000	1.331	0.004	1	2
CH2F2	Methane, difluoro-	rCH	1.084	±0.003	1.089	0.005	1	2
SF	Monosulfur monofluoride	rSF	1.599		1.604	0.005	1	2
SiH3+	Silyl cation	rSiH	1.460	±0.010	1.465	0.005	1	2
C2H3	vinyl	rCH	1.085		1.090	0.005	2	4
H2CS	Thioformaldehyde	rC=S	1.611		1.616	0.006	1	2
LiNH2	lithium amide	rLiN	1.736	±0.003	1.742	0.006	1	2
PF2	Phosphorus difluoride	rPF	1.579		1.585	0.006	1	2
GeCl	Germanium monochloride	rClGe	2.164	±0.000	2.170	0.006	1	2
CSe	Carbon monoselenide	rC=Se	1.676	±0.000	1.682	0.006	1	2
SiH3F	monofluorosilane	rSiF	1.595		1.601	0.006	1	2
SiH2F2	difluorosilane	rSiH	1.462		1.468	0.006	1	4
SiF	silicon monofluoride	rSiF	1.604		1.611	0.006	1	2
BeO	beryllium oxide	rBe=O	1.331		1.338	0.007	1	2
NS	Mononitrogen monosulfide	rNS	1.497	±0.000	1.504	0.007	1	2
GeS	Germanium monosulfide	rS=Ge	2.012	±0.000	2.019	0.007	1	2
AlNC	Aluminum isocyanide	rAlN	1.855	±0.005	1.862	0.007	1	2
GaAs	Gallium arsenide	rGa#As	2.530	±0.020	2.537	0.007	1	2
BrCl	Bromine monochloride	rClBr	2.136	±0.000	2.144	0.008	1	2
ClF	Chlorine monofluoride	rFCl	1.628	±0.000	1.636	0.008	1	2
PN	Phosphorus mononitride	rP#N	1.491		1.499	0.008	1	2
LiOH	lithium hydroxide	rLiO	1.582		1.590	0.008	1	2
SiH3Cl	chlorosilane	rSiCl	2.051		2.060	0.009	1	2
SO	Sulfur monoxide	rS=O	1.481		1.490	0.009	1	2
PO	Phosphorus monoxide	rP=O	1.476		1.486	0.010	1	2
SSO	Disulfur monoxide	rS=O	1.456		1.466	0.010	1	2
SiF2	Silicon difluoride	rFSi	1.590	±0.000	1.600	0.010	1	2
SiO	Silicon monoxide	rSiO	1.510	±0.000	1.520	0.010	1	2
SiCl	Clorosilylidyne	rSiCl	2.061	±0.000	2.073	0.011	1	2
MgH	magnesium monohydride	rMgH	1.730		1.742	0.012	1	2
P2	Phosphorus diatomic	rP#P	1.893		1.905	0.012	1	2
LiH	Lithium Hydride	rLiH	1.595	±0.000	1.607	0.012	1	2
AlF	Aluminum monofluoride	rAlF	1.654	±0.000	1.667	0.013	1	2
LiO	lithium oxide	rLiO	1.688		1.701	0.013	1	2
SiS	silicon monosulfide	rSiS	1.929	±0.000	1.942	0.013	1	2
SCl2	Sulfur dichloride	rSCl	2.013	±0.001	2.026	0.013	1	2
LiF	lithium fluoride	rLiF	1.564	±0.000	1.577	0.013	1	2
S2	Sulfur diatomic	rS=S	1.889		1.903	0.013	1	2
AlC	Aluminum carbide	rC=Al	1.955		1.969	0.014	1	2
AlCl	Aluminum monochloride	rAlCl	2.130	±0.000	2.145	0.015	1	2
SCl	sulfur monochloride	rSCl	1.975		1.990	0.015	1	2
Cl2	Chlorine diatomic	rClCl	1.988		2.003	0.015	1	2
SSO	Disulfur monoxide	rS=S	1.884		1.900	0.015	2	3
HSiCl	Chlorosilylene	rSiCl	2.067	±0.003	2.083	0.016	1	2
C3O2	Carbon suboxide	rC=O	1.146		1.162	0.016	2	4
C3H5	Allyl radical	rCH	1.069		1.085	0.016	1	2
LiBr	Lithium Bromide	rLiBr	2.170	±0.000	2.187	0.017	1	2
ScH	Scandium monohydride	rScH	1.775	±0.000	1.793	0.018	1	2
C2H	Ethynyl radical	rCH	1.047		1.065	0.018	1	3
LiCl	lithium chloride	rLiCl	2.021	±0.000	2.040	0.019	1	2
C3O2	Carbon suboxide	rC=C	1.251		1.276	0.025	1	2
Li2	Lithium diatomic	rLiLi	2.673		2.698	0.025	1	2
CFCl	chlorofluoromethylene	rCCl	1.714		1.748	0.034	1	3
NaH	sodium hydride	rNaH	1.887	±0.000	1.926	0.039	1	2
NaCl	Sodium Chloride	rNaCl	2.361	±0.000	2.404	0.043	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	1.992	0.066	1	2
CaO	Calcium monoxide	rOCa	1.822		1.919	0.096	1	2

191 molecules.