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 CCSD(T)=FULL/cc-pVQZ

Species	Name	Bond type	Bond Length (Å)
			Experimental	unc.	Calculated	Difference	atom1	atom2
NaH	sodium hydride	rNaH	1.887	±0.000	1.760	-0.127	1	2
Na2	Sodium diatomic	rNaNa	3.079		2.961	-0.118	1	2
NaLi	lithium sodium	rLiNa	2.889		2.808	-0.081	1	2
Li2	Lithium diatomic	rLiLi	2.673		2.620	-0.053	1	2
AsH	Arsenic monohydride	rAsH	1.535	±0.001	1.501	-0.033	1	2
C2H2O2	Ethanedial	rCH	1.132		1.100	-0.032	1	3
GeH	germylidene	rGeH	1.588		1.556	-0.032	1	2
AlNC	Aluminum isocyanide	rAlN	1.855	±0.005	1.827	-0.028	1	2
AlC	Aluminum carbide	rC=Al	1.955		1.929	-0.026	1	2
LiOH	lithium hydroxide	rOH	0.969		0.947	-0.023	1	3
ScH	Scandium monohydride	rScH	1.775	±0.000	1.754	-0.021	1	2
HSiCl	Chlorosilylene	rSiH	1.525	±0.005	1.506	-0.019	1	3
AlCl	Aluminum monochloride	rAlCl	2.130	±0.000	2.111	-0.019	1	2
ClO	Monochlorine monoxide	rClO	1.596	±0.001	1.578	-0.018	1	2
GeH3F	monofluorogermane	rGeH	1.515	±0.000	1.498	-0.016	1	3
B2H6	Diborane	rBH	1.200		1.184	-0.016	1	5
H2Cl+	dihydrogen monochloride cation	rHCl	1.321	±0.000	1.305	-0.016	1	2
HeH+	Helium hydride cation	rHHe	0.790		0.775	-0.015	1	2
HF+	hydrogen fluoride cation	rHF	1.014		0.999	-0.015	1	2
CH2NH	Methanimine	rCH	1.103		1.089	-0.014	1	3
HCCl	Chloromethylene	rCH	1.119	±0.036	1.105	-0.014	1	3
GaF	Gallium monofluoride	rFGa	1.774	±0.000	1.761	-0.013	1	2
SiH3Cl	chlorosilane	rSiH	1.475		1.463	-0.012	1	3
B2H6	Diborane	rBH	1.320		1.308	-0.012	1	3
SiH3F	monofluorosilane	rSiH	1.476		1.464	-0.012	1	3
LiNH2	lithium amide	rLiN	1.736	±0.003	1.724	-0.012	1	2
ArH+	Argon hydride cation	rArH	1.292	±0.000	1.280	-0.012	1	2
C2H2O2	Ethanedial	rCC	1.526		1.514	-0.012	1	2
SiH4	Silane	rSiH	1.480	±0.000	1.468	-0.011	1	2
GeF	Germanium monofluoride	rFGe	1.745		1.734	-0.011	1	2
C2H	Ethynyl radical	rC#C	1.217		1.205	-0.011	1	2
NH2F	monofluoroamine	rNF	1.433		1.422	-0.011	1	2
HOCl	hypochlorous acid	rOH	0.973	±0.002	0.962	-0.011	1	2
CH2	Methylene	rCH	1.085		1.074	-0.011	1	2
LiH	Lithium Hydride	rLiH	1.595	±0.000	1.584	-0.011	1	2
CH2PH	Phosphaethene	rCH	1.090	±0.015	1.080	-0.010	1	3
CH3NH2	methyl amine	rCN	1.471	±0.003	1.461	-0.010	1	2
H2Se	Hydrogen selenide	rSeH	1.460		1.450	-0.010	1	2
CH3CHO	Acetaldehyde	rCH	1.114		1.104	-0.010	1	4
SiC	silicon monocarbide	rCSi	1.722		1.712	-0.010	1	2
HS+	sulfur monohydride cation	rSH	1.374		1.365	-0.010	1	2
HNO3	Nitric acid	rNO	1.406		1.396	-0.010	1	2
GaBr	Gallium monobromide	rGaBr	2.352	±0.000	2.343	-0.010	1	2
GeH3F	monofluorogermane	rGeF	1.731	±0.000	1.721	-0.009	1	2
H2CSe	Selenoformaldehyde	rHC	1.090		1.081	-0.009	1	3
LiOH	lithium hydroxide	rLiO	1.582		1.572	-0.009	1	2
SiH	Silylidyne	rSiH	1.520		1.511	-0.009	1	2
NH4+	ammonium cation	rHN	1.029	±0.000	1.020	-0.009	1	2
HOBr	Hypobromous acid	rBrO	1.834		1.825	-0.009	2	3
CH3CCH	propyne	rCH	1.096		1.087	-0.009	1	5
SeCl2	Selenium Dichloride	rClSe	2.157	±0.003	2.148	-0.009	1	2
CH2PH	Phosphaethene	rCH	1.090	±0.015	1.081	-0.009	1	4
CH3NH2	methyl amine	rNH	1.018	±0.001	1.010	-0.008	2	6
SiH+	silicon monohydride cation	rSiH	1.504		1.496	-0.008	1	2
NaF	sodium fluoride	rNaF	1.926	±0.000	1.918	-0.008	1	2
CH2CO	Ketene	rCH	1.083		1.075	-0.008	1	4
HBr+	hydrogen bromide cation	rHBr	1.448		1.441	-0.007	1	2
CH2Br2	dibromomethane	rCBr	1.925	±0.002	1.918	-0.007	1	4
CH3CH2SH	ethanethiol	rCH	1.095		1.088	-0.007	1	4
CHF3	Methane, trifluoro-	rCH	1.091	±0.014	1.084	-0.007	1	2
GeF+	Germanium monofluoride cation	rFGe	1.665	±0.000	1.659	-0.007	1	2
HBr	hydrogen bromide	rHBr	1.414	±0.000	1.408	-0.007	1	2
SiH3+	Silyl cation	rSiH	1.460	±0.010	1.454	-0.006	1	2
SiP	Silicon monophosphide	rSiP	2.078	±0.002	2.072	-0.006	1	2
NO	Nitric oxide	rN=O	1.154	±0.000	1.148	-0.006	1	2
OCSe	Carbonyl selenide	rC=O	1.159		1.153	-0.006	1	2
KrH+	Protonated Krypton	rHKr	1.421	±0.000	1.415	-0.006	1	2
C3H8	Propane	rCH	1.096		1.091	-0.005	1	4
CF	Fluoromethylidyne	rCF	1.276		1.271	-0.005	1	2
SiH2F2	difluorosilane	rSiH	1.462		1.456	-0.005	1	4
CH2Cl2	Methylene chloride	rCH	1.085	±0.002	1.080	-0.005	1	2
N3	azide radical	rNN	1.181		1.177	-0.004	1	2
B2	Boron diatomic	rBB	1.590		1.586	-0.004	1	2
CH3Br	methyl bromide	rCBr	1.934	±0.000	1.930	-0.004	1	2
NH2SH	Thiohydroxylamine	rSH	1.344	±0.029	1.340	-0.004	2	3
LiO	lithium oxide	rLiO	1.688		1.684	-0.004	1	2
C2H2+	acetylene cation	rC=C	1.253	±0.001	1.249	-0.004	1	2
FO	Oxygen monofluoride	rFO	1.354		1.350	-0.004	1	2
SeO2	Selenium dioxide	rSeO	1.607	±0.001	1.603	-0.004	1	2
CH2CHF	Ethene, fluoro-	rCH	1.082		1.078	-0.004	1	4
CH3CH2SH	ethanethiol	rCH	1.092		1.088	-0.004	1	5
C3H4	cyclopropene	rCH	1.088		1.084	-0.004	1	6
H2CSe	Selenoformaldehyde	rC=Se	1.753		1.749	-0.004	1	2
CH3CH2SH	ethanethiol	rCH	1.090		1.086	-0.004	2	7
SeO	Selenium monoxide	rSeO	1.639	±0.001	1.636	-0.004	1	2
BH3	boron trihydride	rBH	1.190		1.187	-0.003	1	2
BH	Boron monohydride	rBH	1.232		1.229	-0.003	1	2
BF	Boron monofluoride	rBF	1.267	±0.000	1.263	-0.003	1	2
HCCl	Chloromethylene	rCCl	1.696	±0.003	1.693	-0.003	1	2
CH	Methylidyne	rCH	1.120		1.117	-0.003	1	2
GeO	Germanium monoxide	rOGe	1.625		1.621	-0.003	1	2
CO+	carbon monoxide cation	rC=O	1.115	±0.000	1.112	-0.003	1	2
HO2	Hydroperoxy radical	rOO	1.331		1.328	-0.003	1	2
OCSe	Carbonyl selenide	rC=Se	1.709		1.706	-0.003	1	3
LiF	lithium fluoride	rLiF	1.564	±0.000	1.561	-0.003	1	2
GeCl	Germanium monochloride	rClGe	2.164	±0.000	2.161	-0.003	1	2
BeH	beryllium monohydride	rBeH	1.343		1.340	-0.002	1	2
SCSe	Carbon sulfide selenide	rC=Se	1.695	±0.002	1.693	-0.002	1	3
Br2	Bromine diatomic	rBrBr	2.281		2.279	-0.002	1	2
HOCl	hypochlorous acid	rClO	1.697	±0.001	1.695	-0.002	1	3
NO+	nitric oxide cation	rN=O	1.066		1.063	-0.002	1	2
DF	Hydrofluoric acid-d	rDF	0.917	±0.000	0.915	-0.002	1	2
PH	phosphorus monohydride	rPH	1.422		1.420	-0.002	1	2
MgH	magnesium monohydride	rMgH	1.730		1.728	-0.002	1	2
HO2	Hydroperoxy radical	rOH	0.971		0.969	-0.002	1	3
C2H2	Acetylene	rCH	1.063		1.061	-0.002	1	3
LiBr	Lithium Bromide	rLiBr	2.170	±0.000	2.169	-0.002	1	2
BrF	Bromine monofluoride	rFBr	1.759	±0.000	1.757	-0.002	1	2
NSe	Nitrogen monoselenide	rN=Se	1.652		1.650	-0.002	1	2
CH4	Methane	rCH	1.087	±0.001	1.085	-0.002	1	2
O2	Oxygen diatomic	rO=O	1.208		1.206	-0.002	1	2
OH-	hydroxide anion	rOH	0.964		0.962	-0.002	1	2
HF	Hydrogen fluoride	rHF	0.917	±0.000	0.915	-0.002	1	2
H2O	Water	rOH	0.958	±0.000	0.956	-0.002	1	2
AlF	Aluminum monofluoride	rAlF	1.654	±0.000	1.653	-0.002	1	2
O2+	diatomic oxygen cation	rOO	1.116		1.115	-0.001	1	2
CH2CO	Ketene	rC=O	1.162		1.161	-0.001	2	3
HNCNH	diiminomethane	rC=N	1.224	±0.001	1.223	-0.001	1	2
OH	Hydroxyl radical	rOH	0.970		0.968	-0.001	1	2
CH3CHO	Acetaldehyde	rCH	1.086		1.085	-0.001	2	5
BN	boron nitride	rB=N	1.325		1.324	-0.001	1	2
CH3Br	methyl bromide	rCH	1.082	±0.001	1.081	-0.001	1	3
He2+	helium diatomic cation	rHeHe	1.081	±0.001	1.080	-0.001	1	2
SiH3F	monofluorosilane	rSiF	1.595		1.594	-0.001	1	2
F2	Fluorine diatomic	rFF	1.412		1.411	-0.001	1	2
BeH2	beryllium dihydride	rBeH	1.326	±0.000	1.326	0.000	1	2
C2	Carbon diatomic	rC=C	1.243		1.242	0.000	1	2
C3H4	cyclopropene	rCH	1.072		1.072	0.000	2	4
GaAs	Gallium arsenide	rGa#As	2.530	±0.020	2.530	0.000	1	2
SiF	silicon monofluoride	rSiF	1.604		1.604	0.000	1	2
BrO	Bromine monoxide	rOBr	1.718		1.718	0.000	1	2
GeS	Germanium monosulfide	rS=Ge	2.012	±0.000	2.012	0.000	1	2
BeO	beryllium oxide	rBe=O	1.331		1.331	0.000	1	2
C2H2+	acetylene cation	rCH	1.077	±0.005	1.077	0.000	1	3
CH2Cl2	Methylene chloride	rCCl	1.767	±0.002	1.767	0.000	1	4
CN-	cyanide anion	rC#N	1.177	±0.004	1.177	0.000	1	2
Se2	Selenium diatomic	rSe=Se	2.166	±0.001	2.166	0.000	1	2
CH3NH2	methyl amine	rCH	1.093	±0.000	1.093	0.000	1	3
BF3	Borane, trifluoro-	rBF	1.307		1.307	0.000	1	2
CH2F2	Methane, difluoro-	rCF	1.351	±0.001	1.351	0.000	1	4
N2	Nitrogen diatomic	rN#N	1.098		1.098	0.000	1	2
H2	Hydrogen diatomic	rHH	0.741		0.742	0.000	1	2
HCl	Hydrogen chloride	rHCl	1.275	±0.000	1.275	0.000	1	2
CH2CHF	Ethene, fluoro-	rCH	1.077		1.078	0.001	2	5
HS	Mercapto radical	rSH	1.341		1.341	0.001	1	2
BO	boron monoxide	rB=O	1.205		1.205	0.001	1	2
CO	Carbon monoxide	rC#O	1.128	±0.000	1.129	0.001	1	2
LiCl	lithium chloride	rLiCl	2.021	±0.000	2.021	0.001	1	2
HCl+	hydrogen chloride cation	rHCl	1.315		1.316	0.001	1	2
SCSe	Carbon sulfide selenide	rC=S	1.553	±0.002	1.554	0.001	1	2
CHF3	Methane, trifluoro-	rCF	1.328	±0.003	1.329	0.001	1	3
CaH	Calcium monohydride	rCaH	2.003	±0.000	2.003	0.001	1	2
CH3CCH	propyne	rCH	1.060		1.061	0.001	3	4
HOBr	Hypobromous acid	rOH	0.961		0.962	0.001	1	2
HS-	mercapto anion	rSH	1.343		1.344	0.001	1	2
C2H2	Acetylene	rC#C	1.203		1.204	0.002	1	2
CH2F2	Methane, difluoro-	rCH	1.084	±0.003	1.086	0.002	1	2
SF	Monosulfur monofluoride	rSF	1.599		1.602	0.003	1	2
C2H3	vinyl	rCH	1.085		1.088	0.003	2	4
H2CS	Thioformaldehyde	rC=S	1.611		1.614	0.003	1	2
CSe	Carbon monoselenide	rC=Se	1.676	±0.000	1.679	0.003	1	2
PF2	Phosphorus difluoride	rPF	1.579		1.582	0.003	1	2
SiH3Cl	chlorosilane	rSiCl	2.051		2.054	0.003	1	2
BrCl	Bromine monochloride	rClBr	2.136	±0.000	2.140	0.004	1	2
PN	Phosphorus mononitride	rP#N	1.491		1.495	0.004	1	2
NS	Mononitrogen monosulfide	rNS	1.497	±0.000	1.501	0.004	1	2
ClF	Chlorine monofluoride	rFCl	1.628	±0.000	1.633	0.005	1	2
SiO	Silicon monoxide	rSiO	1.510	±0.000	1.515	0.005	1	2
SiCl	Clorosilylidyne	rSiCl	2.061	±0.000	2.067	0.006	1	2
PO	Phosphorus monoxide	rP=O	1.476		1.483	0.007	1	2
SO	Sulfur monoxide	rS=O	1.481		1.488	0.007	1	2
SSO	Disulfur monoxide	rS=O	1.456		1.464	0.008	1	2
SiS	silicon monosulfide	rSiS	1.929	±0.000	1.937	0.008	1	2
SO+	sulfur monoxide cation	rO=S	1.424		1.432	0.008	1	2
P2	Phosphorus diatomic	rP#P	1.893		1.902	0.009	1	2
SiBr+	Silicon monobromide cation	rSiBr	2.095	±0.000	2.105	0.009	1	2
SCl2	Sulfur dichloride	rSCl	2.013	±0.001	2.022	0.010	1	2
HSiCl	Chlorosilylene	rSiCl	2.067	±0.003	2.077	0.010	1	2
S2	Sulfur diatomic	rS=S	1.889		1.900	0.011	1	2
SCl	sulfur monochloride	rSCl	1.975		1.987	0.012	1	2
Cl2	Chlorine diatomic	rClCl	1.988		2.000	0.012	1	2
SSO	Disulfur monoxide	rS=S	1.884		1.896	0.012	2	3
PS	phosphorus sulfide	rP=S	1.900		1.913	0.013	1	2
C3O2	Carbon suboxide	rC=O	1.146		1.160	0.014	2	4
C3H5	Allyl radical	rCH	1.069		1.083	0.014	1	2
C2H	Ethynyl radical	rCH	1.047		1.062	0.015	1	3
CaO	Calcium monoxide	rOCa	1.822		1.840	0.018	1	2
C3O2	Carbon suboxide	rC=C	1.251		1.273	0.022	1	2
NaCl	Sodium Chloride	rNaCl	2.361	±0.000	2.384	0.023	1	2
CFCl	chlorofluoromethylene	rCCl	1.714		1.742	0.028	1	3

190 molecules.