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

---

NIST policy on privacy, security, and accessibility.

---

© 2013 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved.

The National Institute of Standards and Technology (NIST) is an agency of the U.S. Department of Commerce.

Please send questions, comments, corrections, additions and suggestions to cccbdb@nist.gov.

IV.D.8.

Average Bond Length Differences by Model Chemistry

Calculated at QCISD(T)=FULL/aug-cc-pVQZ

Species	Name	Bond type	Bond Length (Å)
			Experimental	unc.	Calculated	Difference	atom1	atom2
Na2	Sodium diatomic	rNaNa	3.079		1.953	-1.125	1	2
NaF	sodium fluoride	rNaF	1.926	±0.000	1.737	-0.189	1	2
NaCl	Sodium Chloride	rNaCl	2.361	±0.000	2.278	-0.082	1	2
NaLi	lithium sodium	rLiNa	2.889		2.826	-0.063	1	2
GeH	germylidene	rGeH	1.588		1.544	-0.044	1	2
AsH	Arsenic monohydride	rAsH	1.535	±0.001	1.494	-0.040	1	2
AlNC	Aluminum isocyanide	rAlN	1.855	±0.005	1.815	-0.039	1	2
AlC	Aluminum carbide	rC=Al	1.955		1.919	-0.036	1	2
C2H2O2	Ethanedial	rCH	1.132		1.101	-0.031	1	3
AsH3	Arsine	rAsH	1.511	±0.000	1.483	-0.028	1	2
LiH	Lithium Hydride	rLiH	1.595	±0.000	1.570	-0.025	1	2
ScH	Scandium monohydride	rScH	1.775	±0.000	1.751	-0.025	1	2
GeH3F	monofluorogermane	rGeH	1.515	±0.000	1.491	-0.023	1	3
HSe	Selenium monohydride	rSeH	1.475	±0.010	1.453	-0.022	1	2
LiOH	lithium hydroxide	rOH	0.969		0.947	-0.022	1	3
HSiCl	Chlorosilylene	rSiH	1.525	±0.005	1.503	-0.022	1	3
LiNH2	lithium amide	rLiN	1.736	±0.003	1.718	-0.018	1	2
ClO	Monochlorine monoxide	rClO	1.596	±0.001	1.578	-0.018	1	2
GaBr	Gallium monobromide	rGaBr	2.352	±0.000	2.335	-0.017	1	2
GeF	Germanium monofluoride	rFGe	1.745		1.729	-0.016	1	2
GaF	Gallium monofluoride	rFGa	1.774	±0.000	1.758	-0.016	1	2
LiOH	lithium hydroxide	rLiO	1.582		1.566	-0.016	1	2
B2H6	Diborane	rBH	1.200		1.185	-0.015	1	5
HeH+	Helium hydride cation	rHHe	0.790		0.775	-0.015	1	2
H2Cl+	dihydrogen monochloride cation	rHCl	1.321	±0.000	1.306	-0.015	1	2
AlF	Aluminum monofluoride	rAlF	1.654	±0.000	1.640	-0.014	1	2
HF+	hydrogen fluoride cation	rHF	1.014		1.000	-0.014	1	2
SiH3Cl	chlorosilane	rSiH	1.475		1.461	-0.014	1	3
SiH3F	monofluorosilane	rSiH	1.476		1.463	-0.014	1	3
CH2NH	Methanimine	rCH	1.103		1.090	-0.013	1	3
SiH4	Silane	rSiH	1.480	±0.000	1.467	-0.013	1	2
GaAs	Gallium arsenide	rGa#As	2.530	±0.020	2.517	-0.013	1	2
H2Se	Hydrogen selenide	rSeH	1.460		1.448	-0.012	1	2
B2H6	Diborane	rBH	1.320		1.308	-0.012	1	3
SiH	Silylidyne	rSiH	1.520		1.508	-0.012	1	2
ArH+	Argon hydride cation	rArH	1.292	±0.000	1.280	-0.012	1	2
AsF	Arsenic monofluoride	rFAs	1.736	±0.001	1.724	-0.012	1	2
CH2Br2	dibromomethane	rCBr	1.925	±0.002	1.913	-0.012	1	4
C2H2O2	Ethanedial	rCC	1.526		1.515	-0.011	1	2
GeH3F	monofluorogermane	rGeF	1.731	±0.000	1.720	-0.011	1	2
SiH+	silicon monohydride cation	rSiH	1.504		1.493	-0.011	1	2
CH2	Methylene	rCH	1.085		1.075	-0.010	1	2
HOCl	hypochlorous acid	rOH	0.973	±0.002	0.963	-0.010	1	2
HS+	sulfur monohydride cation	rSH	1.374		1.365	-0.010	1	2
GeF+	Germanium monofluoride cation	rFGe	1.665	±0.000	1.656	-0.009	1	2
GeCl	Germanium monochloride	rClGe	2.164	±0.000	2.154	-0.009	1	2
CH3NH2	methyl amine	rCN	1.471	±0.003	1.462	-0.009	1	2
HBr+	hydrogen bromide cation	rHBr	1.448		1.439	-0.009	1	2
SiH3+	Silyl cation	rSiH	1.460	±0.010	1.451	-0.009	1	2
C2H	Ethynyl radical	rC#C	1.217		1.208	-0.009	1	2
NH4+	ammonium cation	rHN	1.029	±0.000	1.020	-0.009	1	2
CH3Br	methyl bromide	rCBr	1.934	±0.000	1.925	-0.009	1	2
H2CSe	Selenoformaldehyde	rHC	1.090		1.082	-0.008	1	3
CH3CCH	propyne	rCH	1.096		1.088	-0.008	1	5
HBr	hydrogen bromide	rHBr	1.414	±0.000	1.407	-0.008	1	2
CH3NH2	methyl amine	rNH	1.018	±0.001	1.010	-0.008	2	6
SiH2F2	difluorosilane	rSiH	1.462		1.454	-0.007	1	4
CH2CO	Ketene	rCH	1.083		1.076	-0.007	1	4
LiF	lithium fluoride	rLiF	1.564	±0.000	1.557	-0.007	1	2
KrH+	Protonated Krypton	rHKr	1.421	±0.000	1.415	-0.006	1	2
LiO	lithium oxide	rLiO	1.688		1.682	-0.006	1	2
CHF3	Methane, trifluoro-	rCH	1.091	±0.014	1.085	-0.006	1	2
SeO	Selenium monoxide	rSeO	1.639	±0.001	1.634	-0.006	1	2
MgH	magnesium monohydride	rMgH	1.730		1.724	-0.006	1	2
H2CSe	Selenoformaldehyde	rC=Se	1.753		1.748	-0.005	1	2
BrF	Bromine monofluoride	rFBr	1.759	±0.000	1.754	-0.005	1	2
BrO	Bromine monoxide	rOBr	1.718		1.713	-0.005	1	2
C2H2+	acetylene cation	rC=C	1.253	±0.001	1.248	-0.004	1	2
BH	Boron monohydride	rBH	1.232		1.228	-0.004	1	2
OCSe	Carbonyl selenide	rC=O	1.159		1.155	-0.004	1	2
CH2Cl2	Methylene chloride	rCH	1.085	±0.002	1.081	-0.004	1	2
GeO	Germanium monoxide	rOGe	1.625		1.621	-0.004	1	2
CF	Fluoromethylidyne	rCF	1.276		1.273	-0.003	1	2
SeO2	Selenium dioxide	rSeO	1.607	±0.001	1.604	-0.003	1	2
CH2CHF	Ethene, fluoro-	rCH	1.082		1.079	-0.003	1	4
C3H4	cyclopropene	rCH	1.088		1.085	-0.003	1	6
HOCl	hypochlorous acid	rClO	1.697	±0.001	1.694	-0.003	1	3
CH	Methylidyne	rCH	1.120		1.117	-0.003	1	2
OCSe	Carbonyl selenide	rC=Se	1.709		1.706	-0.003	1	3
N3	azide radical	rNN	1.181		1.178	-0.003	1	2
Br2	Bromine diatomic	rBrBr	2.281		2.278	-0.003	1	2
Se2	Selenium diatomic	rSe=Se	2.166	±0.001	2.163	-0.003	1	2
BeH	beryllium monohydride	rBeH	1.343		1.340	-0.003	1	2
SiP	Silicon monophosphide	rSiP	2.078	±0.002	2.075	-0.003	1	2
PH	phosphorus monohydride	rPH	1.422		1.420	-0.002	1	2
LiCl	lithium chloride	rLiCl	2.021	±0.000	2.019	-0.002	1	2
F2	Fluorine diatomic	rFF	1.412		1.411	-0.001	1	2
NO+	nitric oxide cation	rN=O	1.066		1.064	-0.001	1	2
LiBr	Lithium Bromide	rLiBr	2.170	±0.000	2.169	-0.001	1	2
CH4	Methane	rCH	1.087	±0.001	1.086	-0.001	1	2
NO	Nitric oxide	rN=O	1.154	±0.000	1.153	-0.001	1	2
NSe	Nitrogen monoselenide	rN=Se	1.652		1.651	-0.001	1	2
SCSe	Carbon sulfide selenide	rC=Se	1.695	±0.002	1.694	-0.001	1	3
GeS	Germanium monosulfide	rS=Ge	2.012	±0.000	2.011	-0.001	1	2
HO2	Hydroperoxy radical	rOH	0.971		0.970	-0.001	1	3
O2	Oxygen diatomic	rO=O	1.208		1.207	-0.001	1	2
HNCNH	diiminomethane	rC=N	1.224	±0.001	1.224	0.000	1	2
C2H2+	acetylene cation	rCH	1.077	±0.005	1.076	0.000	1	3
CH3Br	methyl bromide	rCH	1.082	±0.001	1.082	0.000	1	3
H2O	Water	rOH	0.958	±0.000	0.958	0.000	1	2
CH2Cl2	Methylene chloride	rCCl	1.767	±0.002	1.767	0.000	1	4
HF	Hydrogen fluoride	rHF	0.917	±0.000	0.917	0.000	1	2
He2+	helium diatomic cation	rHeHe	1.081	±0.001	1.081	0.000	1	2
HO2	Hydroperoxy radical	rOO	1.331		1.331	0.000	1	2
CH2CO	Ketene	rC=O	1.162		1.162	0.000	2	3
C3H4	cyclopropene	rCH	1.072		1.072	0.000	2	4
OH-	hydroxide anion	rOH	0.964		0.964	0.000	1	2
H2	Hydrogen diatomic	rHH	0.741		0.742	0.001	1	2
CH3CCH	propyne	rCH	1.060		1.061	0.001	3	4
HS	Mercapto radical	rSH	1.341		1.342	0.001	1	2
CH3NH2	methyl amine	rCH	1.093	±0.000	1.094	0.001	1	3
N2	Nitrogen diatomic	rN#N	1.098		1.099	0.001	1	2
SiH3F	monofluorosilane	rSiF	1.595		1.596	0.001	1	2
HS-	mercapto anion	rSH	1.343		1.344	0.001	1	2
HCl+	hydrogen chloride cation	rHCl	1.315		1.316	0.001	1	2
SiF	silicon monofluoride	rSiF	1.604		1.606	0.001	1	2
FO	Oxygen monofluoride	rFO	1.354		1.355	0.001	1	2
CH2CHF	Ethene, fluoro-	rCH	1.077		1.078	0.001	2	5
HCl	Hydrogen chloride	rHCl	1.275	±0.000	1.276	0.001	1	2
CO	Carbon monoxide	rC#O	1.128	±0.000	1.130	0.002	1	2
CN-	cyanide anion	rC#N	1.177	±0.004	1.179	0.002	1	2
BrCl	Bromine monochloride	rClBr	2.136	±0.000	2.138	0.002	1	2
SCSe	Carbon sulfide selenide	rC=S	1.553	±0.002	1.555	0.002	1	2
CHF3	Methane, trifluoro-	rCF	1.328	±0.003	1.331	0.002	1	3
CH2F2	Methane, difluoro-	rCF	1.351	±0.001	1.353	0.002	1	4
SiH3Cl	chlorosilane	rSiCl	2.051		2.053	0.002	1	2
PS	phosphorus sulfide	rP=S	1.900		1.903	0.003	1	2
C2	Carbon diatomic	rC=C	1.243		1.245	0.003	1	2
CH2F2	Methane, difluoro-	rCH	1.084	±0.003	1.087	0.003	1	2
BO	boron monoxide	rB=O	1.205		1.208	0.003	1	2
PF2	Phosphorus difluoride	rPF	1.579		1.582	0.003	1	2
BN	boron nitride	rB=N	1.325		1.328	0.003	1	2
SF4	Sulfur tetrafluoride	rSF	1.646	±0.003	1.649	0.003	1	2
C2H3	vinyl	rCH	1.085		1.089	0.004	2	4
H2CS	Thioformaldehyde	rC=S	1.611		1.615	0.004	1	2
SiF2	Silicon difluoride	rFSi	1.590	±0.000	1.594	0.004	1	2
CSe	Carbon monoselenide	rC=Se	1.676	±0.000	1.681	0.004	1	2
SF	Monosulfur monofluoride	rSF	1.599		1.604	0.005	1	2
NS	Mononitrogen monosulfide	rNS	1.497	±0.000	1.502	0.005	1	2
PN	Phosphorus mononitride	rP#N	1.491		1.496	0.005	1	2
SF4	Sulfur tetrafluoride	rSF	1.545	±0.003	1.550	0.005	1	4
SiCl	Clorosilylidyne	rSiCl	2.061	±0.000	2.067	0.006	1	2
SiO	Silicon monoxide	rSiO	1.510	±0.000	1.516	0.007	1	2
SO	Sulfur monoxide	rS=O	1.481		1.489	0.008	1	2
PO	Phosphorus monoxide	rP=O	1.476		1.484	0.009	1	2
SiS	silicon monosulfide	rSiS	1.929	±0.000	1.939	0.010	1	2
HSiCl	Chlorosilylene	rSiCl	2.067	±0.003	2.077	0.010	1	2
SSO	Disulfur monoxide	rS=O	1.456		1.467	0.011	1	2
S2	Sulfur diatomic	rS=S	1.889		1.900	0.011	1	2
Cl2	Chlorine diatomic	rClCl	1.988		2.000	0.012	1	2
SSO	Disulfur monoxide	rS=S	1.884		1.897	0.013	2	3
C3O2	Carbon suboxide	rC=O	1.146		1.161	0.015	2	4
C2H	Ethynyl radical	rCH	1.047		1.062	0.016	1	3
C3O2	Carbon suboxide	rC=C	1.251		1.273	0.022	1	2
CFCl	chlorofluoromethylene	rCCl	1.714		1.741	0.027	1	3

155 molecules.