National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 18October 2016
NIST Standard Reference Database 101
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
VIInput and output files
VIITutorials and Units
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XOlder CCCBDB versions
XIII Vibrations
XIVReaction data
XVEntropy data
XVIBibliographic data
XVIIIon data
XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers

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Molecules with the most calculations producing poor bond lengths

The following table lists molecules sorted by how many calculations produced bond lengths that differ from experiment by more than 0.050 Å.
Click on a name for a table of bond length comparisons.
molecule name poor calculations bond description
Na2 Sodium diatomic 572 rNaNa
Mg2 Magnesium diatomic 502 rMgMg
Cl2 Chlorine diatomic 493 rClCl
Al2Cl6 Aluminum, di-μ-chlorotetrachlorodi- 445 rAlCl
Li2 Lithium diatomic 396 rLiLi
SiP Silicon monophosphide 393 rSiP
CaH Calcium monohydride 393 rHCa
CH2ClCHCHCH3 2-Butene, 1-chloro- 392 rCC
CH2ClCHCHCH3 2-Butene, 1-chloro- 392 rCH
Al2 Aluminum diatomic 389 rAlAl
C3H3NO Oxazole 388 rCH
CH3OC2H5 Ethane, methoxy- 388 rCH
SCl sulfur monochloride 372 rSCl
Be2 Beryllium diatomic 339 rBeBe
ClOF3 Chlorine trifluoride oxide 299 rFCl
O2 Oxygen diatomic 287 rOO
ClF3 Chlorine trifluoride 257 rFCl
Ne2 Neon dimer 243 rNeNe
SOF4 Sulfur tetrafluoride oxide 219 rFS
F2 Fluorine diatomic 206 rFF
LiH Lithium Hydride 201 rLiH
NaLi lithium sodium 199 rLiNa
LiCl lithium chloride 198 rLiCl
SO Sulfur monoxide 198 rSO
SF Monosulfur monofluoride 193 rSF
PS phosphorus sulfide 189 rPS
LiK Lithium Potassium 188 rLiK
SiF silicon monofluoride 185 rSiF
ClF3 Chlorine trifluoride 184 rFCl
ClOF3 Chlorine trifluoride oxide 184 rFCl
CaCl calcium monochloride 183 rClCa
He2+ helium dimer cation 181 rHeHe
HClO4 perchloric acid 178 rOCl
GaAs Gallium arsenide 176 rGaAs
BF Boron monofluoride 176 rBF
Si2 Silicon diatomic 175 rSiSi
LiO lithium oxide 169 rLiO
O2+ diatomic oxygen cation 169 rOO
HClO4 perchloric acid 167 rOCl
SiH2Cl2 dichlorosilane 165 rSiCl
BrO Bromine monoxide 164 rOBr
FO Oxygen monofluoride 161 rFO
ClFO3 Perchloryl fluoride 161 rFCl
NO Nitric oxide 158 rNO
NS Mononitrogen monosulfide 153 rNS
CuH Copper monohydride 153 rHCu
ICl Iodine monochloride 151 rClI
HOBr Hypobromous acid 147 rBrO
AlN Aluminum nitride 147 rNAl
F2SO Thionyl Fluoride 146 rFS
FNO2 Nitryl fluoride 143 rNF
AlO Aluminum monoxide 142 rAlO
N2 Nitrogen diatomic 142 rNN
IF Iodine monofluoride 138 rFI
HO2 Hydroperoxy radical 138 rOO
NaF sodium fluoride 136 rNaF
AlCl Aluminum monochloride 136 rAlCl
NCl nitrogen monochloride 135 rNCl
NaK Sodium Potassium 134 rNaK
IBr Iodine monobromide 134 rBrI
BrF5 bromine pentafluoride 133 rFBr
CaF Calcium monofluoride 132 rFCa
SOF4 Sulfur tetrafluoride oxide 132 rFS
KCl Potassium Chloride 125 rKCl
Se2 Selenium diatomic 121 rSeSe
CaOH Calcium monohydroxide 121 rOCa
PO Phosphorus monoxide 120 rPO
OH- hydroxide anion 119 rOH
CuF Copper monofluoride 118 rCuF
HCl Hydrogen chloride 115 rHCl
CCl carbon monochloride 115 rCCl
S2 Sulfur diatomic 115 rSS
NaCl Sodium Chloride 113 rNaCl
P2 Phosphorus diatomic 112 rPP
B2 Boron diatomic 111 rBB
GeF+ Germanium monofluoride cation 110 rFGe
SiC silicon monocarbide 106 rCSi
HClO4 perchloric acid 103 rOCl
CO Carbon monoxide 103 rCO
TiCl Titanium Monochloride 102 rClTi
PF+ phosphorus monofluoride cation 102 rFP
CuO Copper Monoxide 101 rCuO
ClO Monochlorine monoxide 100 rClO
KH Potassium hydride 99 rHK
SF4 Sulfur tetrafluoride 98 rSF
Cl2+ chlorine diatomic cation 95 rClCl
BrF3 Bromine trifluoride 94 rFBr
C2H6O2S Dimethyl sulfone 94 rSO
CuCl Copper monochloride 92 rCuCl
KBr Potassium Bromide 90 rKBr
AlS Aluminum sulfide 89 rAlS
Cu2 Copper dimer 88 rCuCu
GeCl Germanium monochloride 86 rClGe
P2+ phosphorus dimer cation 86 rPP
NF nitrogen fluoride 86 rNF
F2SO Thionyl Fluoride 85 rOS
ClFO3 Perchloryl fluoride 85 rClO
AlC Aluminum carbide 84 rCAl
SO+ sulfur monoxide cation 84 rOS
CHF2Cl difluorochloromethane 82 rCCl
CH3ONO Methyl nitrite 81 rNO
BrCl Bromine monochloride 81 rClBr
C2H6O2S Dimethyl sulfone 81 rCS
AsF Arsenic monofluoride 80 rFAs
PO- phosphorus monoxide anion 79 rOP
SiF2 Silicon difluoride 79 rFSi
SF4 Sulfur tetrafluoride 77 rSF
SO Sulfur monoxide 77 rOS
CCl2 dichloromethylene 76 rCCl
As4 Arsenic tetramer 74 rAsAs
BF3 Borane, trifluoro- 74 rBF
BeCl beryllium monochloride 73 rBeCl
CH2O2 Dioxirane 73 rOO
PCl5 Phosphorus pentachloride 73 rPCl
CH3NO3 Methyl nitrate 72 rNO
C5H10 2-Pentene, (E)- 71 rCC
Br2 Bromine diatomic 70 rBrBr
PCl5 Phosphorus pentachloride 70 rPCl
NS+ nitrogen sulfide cation 69 rNS
LiCl- lithium chloride anion 69 rLiCl
SSO Disulfur monoxide 69 rSS
SiF4 Silicon tetrafluoride 69 rSiF
CH2FCl fluorochloromethane 68 rCCl
NaH sodium hydride 67 rNaH
PF phosphorus monofluoride 67 rFP
S2+ sulfur dimer cation 66 rSS
SeO Selenium monoxide 66 rSeO
ClF Chlorine monofluoride 66 rFCl
HOCl hypochlorous acid 66 rClO
SSO Disulfur monoxide 64 rSO
SiCl Clorosilylidyne 63 rSiCl
PF5 Phosphorus pentafluoride 63 rPF
BrF Bromine monofluoride 63 rFBr
HNO3 Nitric acid 62 rNO
CH3SCH2CH3 Ethane, (methylthio)- 61 rCS
NaBr Sodium Bromide 61 rNaBr
LiBr Lithium Bromide 60 rLiBr
KF Potassium Fluoride 60 rKF
NO- nitric oxide anion 60 rNO
SeS Selenium monosulfide 60 rSSe
FNO2 Nitryl fluoride 60 rNO
BrF3 Bromine trifluoride 60 rFBr
HF Hydrogen fluoride 59 rHF
CH2O2 Dioxirane 59 rCO
SeO2 Selenium dioxide 59 rSeO
H2CS Thioformaldehyde 58 rCS
PCl phosphorus chloride 57 rPCl
SiH Silylidyne 56 rSiH
SOCl2 thionyl chloride 56 rSO
As2 Arsenic diatomic 56 rAsAs
C3H6 Cyclopropane 56 rCC
CH3COCl Acetyl Chloride 55 rCCl
SiH3F monofluorosilane 55 rSiF
PO2 Phosphorus dioxide 55 rPO
NO+ nitric oxide cation 55 rNO
F2O Difluorine monoxide 54 rFO
C2Cl2 dichloroacetylene 54 rCCl
ArH+ Argon hydride cation 54 rHAr
GeF Germanium monofluoride 53 rFGe
CH3SCH2CH3 Ethane, (methylthio)- 53 rCS
CH3Br methyl bromide 53 rCBr
MgOH magnesium hydroxide 53 rMgO
MgCl magnesium monochloride 52 rMgCl
SiHCl3 Trichlorosilane 52 rSiCl
OH Hydroxyl radical 51 rOH
BrF5 bromine pentafluoride 51 rFBr
CCl2O Phosgene 49 rCCl
C4H10O Ethoxy ethane 47 rCO
CS carbon monosulfide 46 rCS
CH2ClCH2Cl Ethane, 1,2-dichloro- 45 rCCl
AlF Aluminum monofluoride 45 rAlF
PF5 Phosphorus pentafluoride 45 rFP
I2 Iodine diatomic 45 rII
N2O3 Dinitrogen trioxide 44 rNO
SiH3Cl chlorosilane 44 rSiCl
C5H6 Bicyclo[2.1.0]pent-2-ene 44 rCC
LiF lithium fluoride 43 rLiF
NO3 Nitrogen trioxide 43 rNO
SiS silicon monosulfide 42 rSiS
BeO beryllium oxide 42 rBeO
C(CH3)3NH2 2-Propanamine, 2-methyl- 42 rCC
CP Carbon monophosphide 42 rCP
HOBr Hypobromous acid 42 rOH
GaF Gallium monofluoride 41 rFGa
C(CH3)3NH2 2-Propanamine, 2-methyl- 41 rCH
MgS magnesium sulfide 41 rMgS
AlH+ aluminum monohydride cation 40 rHAl
BCl boron monochloride 40 rBCl
ClCN chlorocyanogen 40 rCCl
CFCl3 Trichloromonofluoromethane 40 rCCl
CHClCCl2 Trichloroethylene 39 rCCl
CHClCCl2 Trichloroethylene 39 rCCl
HF+ hydrogen fluoride cation 39 rHF
N2O3 Dinitrogen trioxide 39 rNO
SiH+ silicon monohydride cation 39 rHSi
SiO Silicon monoxide 38 rSiO
H2O Water 38 rOH
CH2Br2 dibromomethane 38 rCBr
GeH germylidene 37 rHGe
CO+ carbon monoxide cation 37 rCO
C3H3NO Oxazole 37 rCO
BeF Beryllium monofluoride 36 rBeF
AsH3 Arsine 36 rHAs
CH3I methyl iodide 36 rCI
CHBr3 bromoform 35 rCBr
HO2 Hydroperoxy radical 34 rOH
CF Fluoromethylidyne 34 rCF
ScH Scandium monohydride 34 rHSc
MgH+ magnesium monohydride cation 34 rHMg
C2Cl2 dichloroacetylene 33 rCC
C2H2 Acetylene 32 rCC
HClO4 perchloric acid 32 rHO
AlH aluminum monohydride 31 rAlH
C2 Carbon diatomic 30 rCC
HS Mercapto radical 30 rSH
CH3ONO Methyl nitrite 29 rNO
CBr4 Carbon tetrabromide 28 rCBr
C5H8 Bicyclo[2.1.0]pentane 28 rCC
N2O3 Dinitrogen trioxide 28 rNO
PN Phosphorus mononitride 28 rPN
BS boron sulfide 27 rBS
CH2C(CH3)OCH3 1-Propene, 2-methoxy- 26 rCO
CSe Carbon monoselenide 24 rCSe
CaOH Calcium monohydroxide 24 rHO
NH Imidogen 24 rNH
MgOH magnesium hydroxide 23 rOH
C2HF3 Trifluoroethylene 23 rCF
CH3ONO Methyl nitrite 23 rCO
SiN Silicon nitride 22 rSiN
MgO magnesium oxide 21 rMgO
C3H8O2 Methane, dimethoxy- 21 rCO
C6H6 Fulvene 21 rCH
C4H10O Methyl propyl ether 21 rCO
C4H5N Cyclopropanecarbonitrile 20 rCC
HCl+ hydrogen chloride cation 20 rHCl
CN Cyano radical 19 rCN
CF3COOH trifluoroacetic acid 19 rCO
C4H10O Propane, 2-methoxy- 19 rCO
C2H3N3 1H-1,2,4-Triazole 19 rCN
MgH magnesium monohydride 19 rMgH
Si(CH3)4 tetramethylsilane 18 rSiC
C3O2 Carbon suboxide 18 rCO
C4 Carbon tetramer 18 rCC
C4H8O2 1,3-Dioxolane, 2-methyl- 18 rCO
CF3COOH trifluoroacetic acid 18 rHO
CH3OCHO methyl formate 18 rCO
DF Hydrofluoric acid-d 18 rDF
DCl Hydrochloric acid-d 17 rDCl
LiOH lithium hydroxide 17 rLiO
N3 azide radical 16 rNN
NH+ imidogen cation 16 rHN
CH2C(CH3)OCH3 1-Propene, 2-methoxy- 16 rCO
CH2NN diazomethane 16 rNN
C2H3N3 1H-1,2,4-Triazole 16 rCN
BeS beryllium sulfide 16 rBeS
C2H5F fluoroethane 15 rCF
C6H5OCH3 Anisole 15 rCO
MgF Magnesium monofluoride 15 rMgF
NH2CONH2 Urea 14 rNH
PH phosphorus monohydride 14 rPH
CF3COOH trifluoroacetic acid 14 rCC
C4H8O2 Ethyl acetate 14 rCO
CH3OCHO methyl formate 14 rCO
CH3OCH3 Dimethyl ether 14 rCO
DS Mercapto-d 14 rSD
HNCO Isocyanic acid 14 rCO
C4H10O Methyl propyl ether 13 rCO
C4H5N (E)-2-Butenenitrile 13 rCC
C4H5N Cyclopropanecarbonitrile 13 rCC
C6H8 Bicyclo[2.1.1]hex-2-ene 13 rCC
C2H3N3 1H-1,2,4-Triazole 13 rCN
OCSe Carbonyl selenide 13 rCO
AsH Arsenic monohydride 12 rHAs
C2H5F fluoroethane 11 rCC
HI Hydrogen iodide 11 rHI
DO Hydroxyl-d 11 rDO
HBr+ hydrogen bromide cation 10 rHBr
CFCl3 Trichloromonofluoromethane 10 rCF
C3H4 cyclopropene 10 rCH
C3H4 cyclopropene 10 rCH
C2- carbon diatomic anion 10 rCC
C5H12O Butane, 1-methoxy- 10 rCO
C2H Ethynyl radical 9 rCC
CH2FCl fluorochloromethane 9 rCF
OCSe Carbonyl selenide 9 rCSe
CH2CO Ketene 8 rCO
CH2CHCHO Acrolein 8 rCC
CH2CHCHO Acrolein 8 rCO
CHF2Cl difluorochloromethane 8 rCF
CN- cyanide anion 8 rCN
C3H4O Cyclopropanone 8 rCC
BN boron nitride 8 rBN
C4H5NO 3-Methylisoxazole 8 rCC
C4H4N2 1,3-Diazine 8 rCN
CSe2 Carbon diselenide 7 rCSe
CH3NC methyl isocyanide 7 rCN
CH2 Methylene 7 rHC
PH+ phosphorus monohydride cation 7 rHP
SiH4 Silane 7 rSiH
CH2NN diazomethane 6 rCN
CH3CH2CHO Propanal 6 rCC
ClCN chlorocyanogen 6 rCN
C3O2 Carbon suboxide 6 rCC
C5H10 2-Pentene, (E)- 6 rCC
C6H5OH phenol 6 rCO
C3H2N2 Malononitrile 6 rCC
C3H8O2 Methane, dimethoxy- 5 rCO
BeH beryllium monohydride 5 rBeH
C4H6 Methylenecyclopropane 5 rCC
C4H6O Cyclobutanone 5 rCC
HNCNH diiminomethane 5 rCN
HS+ sulfur monohydride cation 5 rHS
CH3CH(NH2)COOH Alanine 5 rCC
CH3NHCH3 Dimethylamine 5 rCH
CH3NC methyl isocyanide 5 rCN
CH3CH2CHO Propanal 4 rCC
CH3NH2 methyl amine 4 rCN
CH3NH2 methyl amine 4 rNH
CH3CH2CHO Propanal 4 rCH
CH3CH2CHO Propanal 4 rCH
CH3CH2CHO Propanal 4 rCH
CH3CH2CHO Propanal 4 rCH
C5H6 Bicyclo[2.1.0]pent-2-ene 4 rCC
CH Methylidyne 4 rCH
HBr hydrogen bromide 4 rHBr
Fe(CO)5 Iron pentacarbonyl 4 rCO
C4H6 Bicyclo[1.1.0]butane 4 rCC
C5H10S 2H-Thiopyran, tetrahydro- 4 rCC
C6H12 (E)-3-methylpent-2-ene 4 rCC
C5H7N Cyclobutanecarbonitrile 4 rCC
CCl2O Phosgene 4 rCO
LiOH lithium hydroxide 4 rOH
C5H8 Cyclopentene 3 rCC
C5H8 Spiropentane 3 rCC
C5H10 2-Pentene, (Z)- 3 rCC
C4H6S Thiophene, 2,5-dihydro- 3 rCH
C3H8O2 1,3-Propanediol 3 rOH
C2H2O2 Ethanedial 3 rCH
CH3CH2NH2 Ethylamine 3 rCH
CH3COCl Acetyl Chloride 3 rCO
CH3COCH2CH3 2-Butanone 3 rCC
CH3ONO Methyl nitrite 3 rCH
CH3ONO Methyl nitrite 3 rCH
CH3COCH2CH3 2-Butanone 2 rCC
CH3COCH2CH3 2-Butanone 2 rCH
CH3COCH2CH3 2-Butanone 2 rCH
CH3COCH2CH3 2-Butanone 2 rCH
CH3COCH2CH3 2-Butanone 2 rCH
CH3COCH2CH3 2-Butanone 2 rCH
CH3CH(NH2)COOH Alanine 2 rCC
CH2CCHCH3 1,2-Butadiene 2 rCC
HSe Selenium monohydride 2 rHSe
C5H10 2-Pentene, (Z)- 2 rCH
C5H10O 2-Butanone, 3-methyl- 2 rCC
C5H10O 2-Butanone, 3-methyl- 2 rCH
C4H5NO Isoxazole, 5-methyl- 2 rCC
C5H8 Bicyclo[2.1.0]pentane 2 rCC
C5H8 Cyclobutane, methylene- 2 rCC
C5H8 Cyclobutane, methylene- 2 rCH
C6H6 Fulvene 2 rCC
C6H5OCH3 Anisole 2 rCO
P2H4 H2PPH2 2 rPH
P2H4 H2PPH2 2 rPH
SiH2Cl2 dichlorosilane 2 rSiH
SiH3Cl chlorosilane 1 rSiH
C6H6 Fulvene 1 rCC
C6H12 Cyclohexane 1 rCH
C6H5NH2 aniline 1 rCC
C5H8 Bicyclo[2.1.0]pentane 1 rCC
C5H8O 2H-Pyran, 3,4-dihydro- 1 rCC
C5H9N Pentanenitrile 1 rCC
C8H8 cyclooctatetraene 1 rCC
C6H8 (Z)-hexa-1,3,5-triene 1 rCC
C4H4N2 1,3-Diazine 1 rCN
C4H10O Ethoxy ethane 1 rCC
C4H10O Propane, 2-methoxy- 1 rCH
C4H10O Methyl propyl ether 1 rCC
C5H5N Pyridine 1 rCC
C5H10O 2-Butanone, 3-methyl- 1 rCC
C5H10 2-Pentene, (Z)- 1 rCH
C4H6 Cyclobutene 1 rCC
C5H10 2-Pentene, (Z)- 1 rCC
C2H5N Aziridine 1 rCH
C2H5N Aziridine 1 rCH
C3H4N2 1H-Pyrazole 1 rCH
C3H4N2 1H-Pyrazole 1 rCH
C3H4N2 1H-Pyrazole 1 rCH
C3H5ClO Oxirane, (chloromethyl)- 1 rCC
C2H2O2 Ethanedial 1 rCC
C2H4F2 1,2-difluoroethane 1 rCC
C2H3N3 1H-1,2,4-Triazole 1 rCN
C10H8 naphthalene 1 rCC
BH+ boron monohydride cation 1 rHB
HD Deuterium hydride 1 rDH
H2Se Hydrogen selenide 1 rHSe
H2 Hydrogen diatomic 1 rHH
D2 Deuterium diatomic 1 rDD
CH2CHCH2CH3 1-Butene 1 rCC
CH2CHOCHCH2 Vinyl ether 1 rCO
CH2C(CH3)OCH3 1-Propene, 2-methoxy- 1 rCH
CH3CH2SH ethanethiol 1 rCH
CH3CH2SH ethanethiol 1 rCH
CH3COCl Acetyl Chloride 1 rCC
CH3OCHO methyl formate 1 rCH
CH3OCHO methyl formate 1 rCH
CHF2Cl difluorochloromethane 1 rCH