National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 17bSeptember 2015
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 565 rNaNa
Mg2 Magnesium diatomic 495 rMgMg
Cl2 Chlorine diatomic 466 rClCl
Al2Cl6 Aluminum, di-μ-chlorotetrachlorodi- 438 rAlCl
Li2 Lithium diatomic 390 rLiLi
CaH Calcium monohydride 388 rHCa
SiP Silicon monophosphide 386 rSiP
CH2ClCHCHCH3 2-Butene, 1-chloro- 385 rCC
CH2ClCHCHCH3 2-Butene, 1-chloro- 385 rCH
Al2 Aluminum diatomic 383 rAlAl
C3H3NO Oxazole 381 rCH
CH3OC2H5 Ethane, methoxy- 381 rCH
SCl sulfur monochloride 355 rSCl
Be2 Beryllium diatomic 332 rBeBe
O2 Oxygen diatomic 281 rOO
ClF3 Chlorine trifluoride 253 rFCl
Ne2 Neon dimer 236 rNeNe
F2 Fluorine diatomic 206 rFF
SO Sulfur monoxide 197 rSO
LiH Lithium Hydride 195 rLiH
LiCl lithium chloride 193 rLiCl
NaLi lithium sodium 192 rLiNa
SF Monosulfur monofluoride 192 rSF
PS phosphorus sulfide 188 rPS
LiK Lithium Potassium 182 rLiK
ClF3 Chlorine trifluoride 182 rFCl
HClO4 perchloric acid 178 rOCl
CaCl calcium monochloride 178 rClCa
BF Boron monofluoride 176 rBF
He2+ helium dimer cation 174 rHeHe
GaAs Gallium arsenide 172 rGaAs
LiO lithium oxide 169 rLiO
Si2 Silicon diatomic 169 rSiSi
O2+ diatomic oxygen cation 168 rOO
HClO4 perchloric acid 166 rOCl
SiH2Cl2 dichlorosilane 164 rSiCl
BrO Bromine monoxide 162 rOBr
FO Oxygen monofluoride 160 rFO
ClFO3 Perchloryl fluoride 154 rFCl
CuH Copper monohydride 152 rHCu
NS Mononitrogen monosulfide 152 rNS
ICl Iodine monochloride 150 rClI
HOBr Hypobromous acid 146 rBrO
AlN Aluminum nitride 146 rNAl
F2SO Thionyl Fluoride 145 rFS
AlO Aluminum monoxide 140 rAlO
HO2 Hydroperoxy radical 137 rOO
IF Iodine monofluoride 137 rFI
NaF sodium fluoride 136 rNaF
IBr Iodine monobromide 133 rBrI
NaK Sodium Potassium 132 rNaK
NCl nitrogen monochloride 130 rNCl
NO Nitric oxide 129 rNO
AlCl Aluminum monochloride 129 rAlCl
BrF5 bromine pentafluoride 127 rFBr
CaF Calcium monofluoride 126 rFCa
KCl Potassium Chloride 120 rKCl
PO Phosphorus monoxide 119 rPO
Se2 Selenium diatomic 119 rSeSe
CaOH Calcium monohydroxide 116 rOCa
CuF Copper monofluoride 116 rCuF
CCl carbon monochloride 114 rCCl
S2 Sulfur diatomic 114 rSS
NaCl Sodium Chloride 112 rNaCl
N2 Nitrogen diatomic 112 rNN
P2 Phosphorus diatomic 112 rPP
B2 Boron diatomic 104 rBB
HClO4 perchloric acid 102 rOCl
TiCl Titanium Monochloride 102 rClTi
CuO Copper Monoxide 99 rCuO
ClO Monochlorine monoxide 99 rClO
HCl Hydrogen chloride 98 rHCl
SiF silicon monofluoride 98 rSiF
SF4 Sulfur tetrafluoride 97 rSF
PF+ phosphorus monofluoride cation 96 rFP
KH Potassium hydride 96 rHK
Cl2+ chlorine diatomic cation 94 rClCl
CuCl Copper monochloride 92 rCuCl
CO Carbon monoxide 92 rCO
BrF3 Bromine trifluoride 91 rFBr
AlS Aluminum sulfide 88 rAlS
C2H6O2S Dimethyl sulfone 87 rSO
Cu2 Copper dimer 86 rCuCu
KBr Potassium Bromide 85 rKBr
NF nitrogen fluoride 85 rNF
P2+ phosphorus dimer cation 84 rPP
F2SO Thionyl Fluoride 84 rOS
GeCl Germanium monochloride 83 rClGe
AlC Aluminum carbide 83 rCAl
SO+ sulfur monoxide cation 83 rOS
ClFO3 Perchloryl fluoride 82 rClO
CH3ONO Methyl nitrite 81 rNO
CHF2Cl difluorochloromethane 80 rCCl
AsF Arsenic monofluoride 80 rFAs
PO- phosphorus monoxide anion 79 rOP
SiF2 Silicon difluoride 78 rFSi
BrCl Bromine monochloride 78 rClBr
SF4 Sulfur tetrafluoride 76 rSF
SO Sulfur monoxide 76 rOS
CCl2 dichloromethylene 75 rCCl
BF3 Borane, trifluoro- 74 rBF
C2H6O2S Dimethyl sulfone 74 rCS
As4 Arsenic tetramer 73 rAsAs
BeCl beryllium chloride 72 rBeCl
CH3NO3 Methyl nitrate 72 rNO
CH2O2 Dioxirane 72 rOO
C5H10 2-Pentene, (E)- 70 rCC
PCl5 Phosphorus pentachloride 70 rPCl
PCl5 Phosphorus pentachloride 69 rPCl
SSO Disulfur monoxide 68 rSS
NS+ nitrogen sulfide cation 68 rNS
Br2 Bromine diatomic 67 rBrBr
CH2FCl fluorochloromethane 67 rCCl
PF phosphorus monofluoride 66 rFP
NaH sodium hydride 66 rNaH
HOCl hypochlorous acid 65 rClO
LiCl- lithium chloride anion 65 rLiCl
S2+ sulfur dimer cation 65 rSS
SeO Selenium monoxide 65 rSeO
ClF Chlorine monofluoride 65 rFCl
SSO Disulfur monoxide 63 rSO
SiF4 Silicon tetrafluoride 62 rSiF
SiCl Clorosilylidyne 62 rSiCl
PF5 Phosphorus pentafluoride 62 rPF
HNO3 Nitric acid 61 rNO
BrF Bromine monofluoride 61 rFBr
NaBr Sodium Bromide 60 rNaBr
LiBr Lithium Bromide 59 rLiBr
NO- nitric oxide anion 59 rNO
BrF3 Bromine trifluoride 59 rFBr
HF Hydrogen fluoride 59 rHF
CH2O2 Dioxirane 59 rCO
SeO2 Selenium dioxide 58 rSeO
SeS Selenium monosulfide 58 rSSe
PCl phosphorus chloride 56 rPCl
KF Potassium Fluoride 56 rKF
C3H6 Cyclopropane 56 rCC
As2 Arsenic diatomic 55 rAsAs
SiH Silylidyne 55 rSiH
SOCl2 thionyl chloride 55 rSO
SiH3F monofluorosilane 54 rSiF
PO2 Phosphorus dioxide 54 rPO
CH3COCl Acetyl Chloride 54 rCCl
CH3SCH2CH3 Ethane, (methylthio)- 54 rCS
GeF Germanium monofluoride 53 rFGe
F2O Difluorine monoxide 53 rFO
C2Cl2 dichloroacetylene 53 rCCl
MgOH magnesium hydroxide 53 rMgO
CH3Br methyl bromide 52 rCBr
BrF5 bromine pentafluoride 51 rFBr
OH Hydroxyl radical 51 rOH
SiHCl3 Trichlorosilane 51 rSiCl
MgCl magnesium monochloride 49 rMgCl
NO+ nitric oxide cation 48 rNO
CCl2O Phosgene 48 rCCl
ArH+ Argon hydride cation 47 rHAr
CH3SCH2CH3 Ethane, (methylthio)- 46 rCS
CS carbon monosulfide 45 rCS
AlF Aluminum monofluoride 45 rAlF
C5H6 Bicyclo[2.1.0]pent-2-ene 44 rCC
CH2ClCH2Cl Ethane, 1,2-dichloro- 44 rCCl
N2O3 Dinitrogen trioxide 44 rNO
I2 Iodine diatomic 44 rII
LiF lithium fluoride 43 rLiF
SiH3Cl chlorosilane 43 rSiCl
OH- hydroxide anion 42 rOH
HOBr Hypobromous acid 42 rOH
BeO beryllium oxide 42 rBeO
CP Carbon monophosphide 41 rCP
PF5 Phosphorus pentafluoride 41 rFP
SiS silicon monosulfide 41 rSiS
MgS magnesium sulfide 40 rMgS
GaF Gallium monofluoride 40 rFGa
C4H10O Ethoxy ethane 40 rCO
AlH+ aluminum monohydride cation 39 rHAl
BCl boron monochloride 39 rBCl
HF+ hydrogen fluoride cation 39 rHF
ClCN chlorocyanogen 39 rCCl
CFCl3 Trichloromonofluoromethane 39 rCCl
N2O3 Dinitrogen trioxide 39 rNO
SiH+ silicon monohydride cation 39 rHSi
CHClCCl2 Trichloroethylene 38 rCCl
CHClCCl2 Trichloroethylene 38 rCCl
H2O Water 38 rOH
GeH germylidene 37 rHGe
CO+ carbon monoxide cation 37 rCO
CH2Br2 dibromomethane 37 rCBr
SiO Silicon monoxide 37 rSiO
NO3 Nitrogen trioxide 36 rNO
BeF Beryllium monofluoride 36 rBeF
C3H3NO Oxazole 36 rCO
C(CH3)3NH2 2-Propanamine, 2-methyl- 35 rCC
CH3I methyl iodide 35 rCI
CF Fluoromethylidyne 34 rCF
CHBr3 bromoform 34 rCBr
HO2 Hydroperoxy radical 34 rOH
C(CH3)3NH2 2-Propanamine, 2-methyl- 34 rCH
ScH Scandium monohydride 34 rHSc
MgH+ magnesium monohydride cation 33 rHMg
C2Cl2 dichloroacetylene 32 rCC
C2H2 Acetylene 32 rCC
HClO4 perchloric acid 32 rHO
C2 Carbon diatomic 30 rCC
AlH aluminum monohydride 30 rAlH
SH Mercapto radical 30 rSH
AsH3 Arsine 29 rHAs
CH3ONO Methyl nitrite 29 rNO
C5H8 Bicyclo[2.1.0]pentane 28 rCC
CBr4 Carbon tetrabromide 28 rCBr
N2O3 Dinitrogen trioxide 28 rNO
PN Phosphorus mononitride 27 rPN
BS boron sulfide 27 rBS
CH2C(CH3)OCH3 1-Propene, 2-methoxy- 25 rCO
NH Imidogen 24 rNH
MgOH magnesium hydroxide 23 rOH
CH3ONO Methyl nitrite 23 rCO
CSe Carbon monoselenide 23 rCSe
C2HF3 Trifluoroethylene 23 rCF
CaOH Calcium monohydroxide 23 rHO
C6H6 Fulvene 21 rCH
C4H10O Methyl propyl ether 21 rCO
MgO magnesium oxide 21 rMgO
SiN Silicon nitride 21 rSiN
C3H8O2 Methane, dimethoxy- 20 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
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
Si(CH3)4 tetramethylsilane 18 rSiC
MgH magnesium monohydride 17 rMgH
LiOH lithium hydroxide 17 rLiO
DCl Hydrochloric acid-d 17 rDCl
H2CS Thioformaldehyde 17 rCS
CH2C(CH3)OCH3 1-Propene, 2-methoxy- 16 rCO
C2H3N3 1H-1,2,4-Triazole 16 rCN
BeS beryllium sulfide 16 rBeS
N3 azide radical 16 rNN
NH+ imidogen cation 16 rHN
MgF Magnesium monofluoride 15 rMgF
C2H5F fluoroethane 15 rCF
C6H5OCH3 Anisole 15 rCO
CH2NN diazomethane 15 rNN
CH3OCHO methyl formate 14 rCO
CH3OCH3 Dimethyl ether 14 rCO
CF3COOH trifluoroacetic acid 14 rCC
HNCO Isocyanic acid 14 rCO
DS Mercapto-d 14 rSD
NH2CONH2 Urea 14 rNH
PH phosphorus monohydride 14 rPH
OCSe Carbonyl selenide 13 rCO
C6H8 Bicyclo[2.1.1]hex-2-ene 13 rCC
C4H5N Cyclopropanecarbonitrile 13 rCC
C4H10O Methyl propyl ether 13 rCO
C4H5N (E)-2-Butenenitrile 13 rCC
C2H3N3 1H-1,2,4-Triazole 13 rCN
AsH Arsenic monohydride 12 rHAs
C2H5F fluoroethane 11 rCC
DO Hydroxyl-d 11 rDO
HI Hydrogen iodide 10 rHI
HBr+ hydrogen bromide cation 10 rHBr
CFCl3 Trichloromonofluoromethane 10 rCF
C3H4 cyclopropene 10 rCH
C3H4 cyclopropene 10 rCH
C3H4N2 1H-Imidazole 10 rCN
C2- carbon diatomic anion 10 rCC
C5H12O Butane, 1-methoxy- 10 rCO
CH2FCl fluorochloromethane 9 rCF
OCSe Carbonyl selenide 9 rCSe
CH2CO Ketene 8 rCO
CH2CHCHO Acrolein 8 rCC
CH2CHCHO Acrolein 8 rCO
CN- cyanide anion 8 rCN
CHF2Cl difluorochloromethane 8 rCF
C5H8 Ethenylcyclopropane 8 rCC
C4H4N2 1,3-Diazine 8 rCN
C4H5NO 3-Methylisoxazole 8 rCC
C3H4O Cyclopropanone 8 rCC
C3H4N2 1H-Imidazole 7 rCN
BN boron nitride 7 rBN
C4H8O2 Ethyl acetate 7 rCO
CSe2 Carbon diselenide 7 rCSe
CH2 Methylene 7 rHC
CH3NC methyl isocyanide 7 rCN
PH+ phosphorus monohydride cation 7 rHP
CH2NN diazomethane 6 rCN
CH3CH2CHO Propanal 6 rCC
ClCN chlorocyanogen 6 rCN
C5H10 2-Pentene, (E)- 6 rCC
C3O2 Carbon suboxide 6 rCC
C6H5OH phenol 6 rCO
C3H2N2 Malononitrile 6 rCC
C2H Ethynyl radical 6 rCC
BeH beryllium monohydride 5 rBeH
C3H8O2 Methane, dimethoxy- 5 rCO
C4H6 Methylenecyclopropane 5 rCC
C4H6O Cyclobutanone 5 rCC
HNCNH diiminomethane 5 rCN
CH3NC methyl isocyanide 5 rCN
CH3NHCH3 Dimethylamine 5 rCH
CH3CH(NH2)COOH Alanine 5 rCC
SH+ sulfur monohydride cation 5 rHS
LiOH lithium hydroxide 4 rOH
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
CCl2O Phosgene 4 rCO
HBr hydrogen bromide 4 rHBr
Fe(CO)5 Iron pentacarbonyl 4 rCO
C4H6 Bicyclo[1.1.0]butane 4 rCC
C6H12 (E)-3-methylpent-2-ene 4 rCC
C5H10S 2H-Thiopyran, tetrahydro- 4 rCC
C5H7N Cyclobutanecarbonitrile 4 rCC
C5H8 Spiropentane 3 rCC
C5H8 Cyclopentene 3 rCC
C4H6S Thiophene, 2,5-dihydro- 3 rCH
C5H10 2-Pentene, (Z)- 3 rCC
C3H8O2 1,3-Propanediol 3 rOH
C2H2O2 Ethanedial 3 rCH
CH3CH2NH2 Ethylamine 3 rCH
CH3ONO Methyl nitrite 3 rCH
CH3ONO Methyl nitrite 3 rCH
CH3COCl Acetyl Chloride 3 rCO
CH3COCH2CH3 2-Butanone 3 rCC
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
C3H4N2 1H-Imidazole 2 rCH
C3H4N2 1H-Imidazole 2 rCH
C3H4N2 1H-Imidazole 2 rCH
C3H4N2 1H-Imidazole 2 rCN
C5H10 2-Pentene, (Z)- 2 rCH
C5H10O 2-Butanone, 3-methyl- 2 rCC
C4H5NO Isoxazole, 5-methyl- 2 rCC
C5H8 Cyclobutane, methylene- 2 rCC
C5H8 Cyclobutane, methylene- 2 rCH
C5H8 Bicyclo[2.1.0]pentane 2 rCC
C5H10O 2-Butanone, 3-methyl- 2 rCH
C6H5OCH3 Anisole 2 rCO
C6H6 Fulvene 2 rCC
HSe Selenium monohydride 2 rHSe
P2H4 H2PPH2 2 rPH
P2H4 H2PPH2 2 rPH
SiH2Cl2 dichlorosilane 2 rSiH
SiH3Cl chlorosilane 1 rSiH
SiH4 Silane 1 rSiH
C6H6 Fulvene 1 rCC
C6H8 (Z)-hexa-1,3,5-triene 1 rCC
C6H12 Cyclohexane 1 rCH
C6H5NH2 aniline 1 rCC
C8H8 cyclooctatetraene 1 rCC
C5H5N Pyridine 1 rCC
C5H8 Bicyclo[2.1.0]pentane 1 rCC
C5H8 Ethenylcyclopropane 1 rCC
C5H8O 2H-Pyran, 3,4-dihydro- 1 rCC
C5H9N Pentanenitrile 1 rCC
C4H6 Cyclobutene 1 rCC
C5H10O 2-Butanone, 3-methyl- 1 rCC
C5H10 2-Pentene, (Z)- 1 rCH
C5H10 2-Pentene, (Z)- 1 rCC
C4H10O Ethoxy ethane 1 rCC
C4H4N2 1,3-Diazine 1 rCN
C4H10O Propane, 2-methoxy- 1 rCH
C4H10O Methyl propyl ether 1 rCC
C3H4N2 1H-Pyrazole 1 rCH
C3H4N2 1H-Pyrazole 1 rCH
C3H4N2 1H-Pyrazole 1 rCH
C3H5ClO Oxirane, (chloromethyl)- 1 rCC
C2H5N Aziridine 1 rCH
C2H5N Aziridine 1 rCH
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
CH2CHCH2CH3 1-Butene 1 rCC
CH2C(CH3)OCH3 1-Propene, 2-methoxy- 1 rCH
CH3CH2SH ethanethiol 1 rCH
CH3CH2SH ethanethiol 1 rCH
CH2CHOCHCH2 Vinyl ether 1 rCO
CH3COCl Acetyl Chloride 1 rCC
CH3OCHO methyl formate 1 rCH
CH3OCHO methyl formate 1 rCH
H2 Hydrogen diatomic 1 rHH
H2Se Hydrogen selenide 1 rHSe
HD Deuterium hydride 1 rDH
CHF2Cl difluorochloromethane 1 rCH
D2 Deuterium diatomic 1 rDD