National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 22May 2022
NIST Standard Reference Database 101
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XIVReaction data
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XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers

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Compare Barriers to Internal Rotation in two species

Species with internal rotation data. The listed barrier is from computations at HF/6-31G* and represents the maximum barrier. Barrier is in kJ mol-1.

Select Species Name Approx. rotor type Barrier
B2Cl4 Diboron tetrachloride BCl2 12.1
C14H14 Bibenzyl benzyl 31.3
B2F4 Diboron tetrafluoride BF2 1.2
B2H4 Diborane(4) D2d BH2 43.8
BH3PH3 borane phosphine BH3 8.0
BH3NH3 borane ammonia BH3 7.7
BH3 boron trihydride BH3 umbrella 249.7
CH2CHCHCH2 1,3-Butadiene C2H3 25.3
CH2CHCH2CH3 1-Butene C2H3 10.4
C5H8 1,4-Pentadiene C2H3 13.0
CH2CHOCHCH2 Vinyl ether C2H3 11.5
C6H6 Hexa-1,5-diene-3-yne C2H3 2.0
C6H5CHCH2 Styrene C2H3 12.0
CH3CH2CH2CN Butanenitrile C2H5 20.0
CH3CHFCH2CH3 2-fluorobutane C2H5 26.1
C12H10 biphenyl C6H5 13.7
CH2SHCH2SH 1,2-Ethanedithiol CC 36.5
C2H Ethynyl radical CCH bend 172.9
CHCl2CClF2 Ethane, 1,2,2-trichloro-1,1-difluoro- CClF2 35.8
C2H6O2 1,2-Ethanediol CCOH 45.3
C2F4 Tetrafluoroethylene CF2 442.2
CF2ClCFCl2 Ethane, 1,1,2-trichloro-1,2,2-trifluoro- CF2Cl 43.4
CF2ClCF2Cl 1,2-Dichloro-1,1,2,2-tetrafluoroethane CF2Cl 39.4
C2F6 hexafluoroethane CF3 16.5
CH3CH methylmethylene CH 1.7
C2H4 Ethylene CH2 457.9
C2H4+ Ethylene cation CH2 169.3
C3H7 n-Propyl radical CH2 1.2
CH2CHO Vinyloxy radical CH2 57.6
C6H5CH2 benzyl radical CH2 70.9
C4H8 cyclobutane CH2 umbrella 56.4
CH2Cl chloromethyl radical CH2 wag 70.3
CH2BrCH2Br Ethane, 1,2-dibromo- CH2Br 41.8
CH3CH2CH2Br n-propyl bromide CH2Br 24.3
CH3CH2CH2CH3 Butane CH2CH3 25.9
C3H7OH 1-Propanol CH2CH3 22.6
C3H7NO Propanamide CH2CH3 7.1
CH3COCH2CH3 2-Butanone CH2CH3 12.1
CH3CHClCH2CH3 Butane, 2-chloro- CH2CH3 26.6
C2H5NO3 Nitric acid, ethyl ester CH2CH3 43.4
CH2BrCH2Cl 1-bromo-2-chloroethane CH2Cl 42.2
CH2ClCH2Cl Ethane, 1,2-dichloro- CH2Cl 41.8
CH2ClCH2OH 2-Chloroethanol CH2Cl 43.3
CH2ClCH2CH3 Propane, 1-chloro- CH2Cl 26.4
CH2ClCHCl2 1,1,2-trichloroethane CH2Cl 37.4
CH2ClCHCHCH3 2-Butene, 1-chloro- CH2Cl 12.4
C4H4N2 Succinonitrile CH2CN 27.8
C2H4F2 1,2-difluoroethane CH2F 33.3
CH2FCH2Cl Ethane, 1-chloro-2-fluoro- CH2F 32.6
CH2CHCH2F Allyl Fluoride CH2F 13.4
CH2FCH2CH3 1-Fluoropropane CH2F 19.7
CHF2CH2F Ethane, 1,1,2-trifluoro CH2F 24.7
CH2FCH2CH2F 1,3-difluoropropane CH2F 24.8
H2NCH2COOH Glycine CH2NH2 13.4
C2H5 Ethyl radical CH3 0.6
CH3SiH3 methyl silane CH3 5.9
C2H6 Ethane CH3 12.5
CH3NH3+ protonated methylamine CH3 9.9
CH2CHCH3 Propene CH3 8.6
C3H8 Propane CH3 30.5
C3H8 Propane CH3 30.5
CH3NHCH3 Dimethylamine CH3 26.3
CH3NHCH3 Dimethylamine CH3 26.3
CH3OO methylperoxy radical CH3 5.6
CH3CO Acetyl radical CH3 1.7
CH3OOH Methyl peroxide CH3 14.2
CH3CHS Thioacetaldehyde CH3 6.5
CH3CHO Acetaldehyde CH3 4.3
CH3CH2O Ethoxy radical CH3 12.8
CH3CH2SH ethanethiol CH3 36.5
CH3CH2OH Ethanol CH3 15.2
CH3SCH3 Dimethyl sulfide CH3 17.9
CH3OCH3 Dimethyl ether CH3 19.4
CH3OCH3 Dimethyl ether CH3 19.4
C2H5F fluoroethane CH3 15.2
C2H5Br Ethyl bromide CH3 16.5
CH3CH2Cl Ethyl chloride CH3 16.2
CHCCH2CH3 1-Butyne CH3 14.6
CH2CCHCH3 1,2-Butadiene CH3 7.3
CH2C(CH3)CH3 1-Propene, 2-methyl- CH3 21.6
CH3CH2CH2CH3 Butane CH3 26.9
C2H5CN ethyl cyanide CH3 13.8
CH3NO2 Methane, nitro- CH3 0.0
CH3COO- acetate anion CH3 0.0
C3H4O Methylketene CH3 5.6
CH3CONH2 Acetamide CH3 0.4
CH3SOCH3 Dimethyl sulfoxide CH3 27.1
C3H6O Propylene oxide CH3 11.1
CH3COCl Acetyl Chloride CH3 5.4
CH3COF Acetyl fluoride CH3 5.2
CH3CHF2 Ethane, 1,1-difluoro- CH3 15.1
CH3CHCl2 Ethane, 1,1-dichloro- CH3 19.9
CH3CHFCl Ethane, 1-chloro-1-fluoro- CH3 17.5
C5H12 Propane, 2,2-dimethyl- CH3 17.8
CH3COOCH3 methyl acetate CH3 55.8
SiCl3CH3 methyltrichlorosilane CH3 7.6
CH3CCl3 Ethane, 1,1,1-trichloro- CH3 25.5
CH3CF3 Ethane, 1,1,1-trifluoro- CH3 14.6
C6H10 Cyclopentene, 1-methyl- CH3 9.0
C6H5CH3 toluene CH3 0.0
CH3COCH3 Acetone CH3 A2 9.0
CH3COCH3 Acetone CH3 B1 9.0
CH3 Methyl radical CH3 umbrella 458.2
CH3OOCH3 dimethylperoxide CH3O 57.1
CH3OCH2CN Methoxyacetonitrile CH3O 19.3
CH3COOCH3 methyl acetate CH3O 55.8
CHCl2CH2CH3 1,1-dichloropropane CHCl2 27.6
CHCl2CHCl2 Ethane, 1,1,2,2-tetrachloro- CHCl2 54.9
C4H8Cl2 Butane, 2,3-dichloro-, (r*,r*)-(.+/-.)- CHClCH3 39.7
C4H8Cl2 Butane, 2,3-dichloro-, (r*,s*)- CHClCH3 54.0
CHF2CHF2 1,1,2,2-tetrafluoroethane CHF2 31.6
CF3CHF2 pentafluoroethane CHF2 16.1
CHFClCHFCl 1,2-dichloro-1,2-difluoroethane RR CHFCl 34.3
CHFClCHClF ethane, 1,2-dichloro-1,2-difluoro- CHFCl 48.0
C2H2O2 Ethanedial CHO 30.0
CH3OCHO methyl formate CHO 53.5
CHOCH2OH hydroxy acetaldehyde CHO 19.0
CH2CHCHO Acrolein CHO 34.3
CH3CH2CHO Propanal CHO 8.6
CH2ClCHO chloroacetaldehyde CHO 14.3
CH2FCHO Fluoroacetaldehyde CHO 23.4
CHOOCHO diformyl ether CHO 41.4
CHCl2CHO dichloroacetaldehyde CHO 19.0
C2H4N2O2 Oxalamide CHO 60.2
C5H4O2 furfural CHO 45.5
C6H5CHO benzaldehyde CHO 36.8
C5H11N Piperidine CNH bend 89.2
CH3COC6H5 acetophenone COCH3 25.9
C6H5COOH benzoic acid COOH 34.0
CH2SHCH2SH 1,2-Ethanedithiol CS 10.3
C3H6S Thietane CSC wag 63.3
CuCN Copper cyanide CuCN 39.6
PF5 Phosphorus pentafluoride FPF bend 23.2
HCNO fulminic acid HC 54.2
HCCN cyanomethylene HCC bend 128.5
HCOOC2H5 Ethyl formate HCO 51.6
HOF Hypofluorous acid HOF bend 354.5
KCN Potassium cyanide KCN bend 23.5
MgOH magnesium hydroxide MgOH bend 71.0
NaOH sodium hydroxide NaOH bend 25.4
N2F2 (Z)-Difluorodiazene NF 406.3
HNCNH diiminomethane NH 38.4
N2H4 Hydrazine NH2 43.9
CH3NH2 methyl amine NH2 10.0
CH3CH2NH2 Ethylamine NH2 11.7
CHONH2 formamide NH2 77.6
NH2CH2CH2CH3 1-Propanamine NH2 11.5
CH3CONH2 Acetamide NH2 46.0
C6H5NH2 aniline NH2 15.9
NH2CN cyanamide NH2 wag 57.3
CHONH2 formamide NH2 wag 256.5
C6H5NH2 aniline NH2 wag 157.5
NH3 Ammonia NH3 umbrella 257.3
ONNO NO dimer NO 8.2
CH3ONO Methyl nitrite NO 48.0
ClONO chlorine nitrite NO 48.2
FONO Nitrosyl hypofluorite NO 55.9
N2O3 Dinitrogen trioxide NO2 14.8
N2O4 Dinitrogen tetroxide NO2 17.3
C6H5NO2 Nitrobenzene NO2 31.7
C2H6O2 1,2-Ethanediol OCCO 45.3
ClOOCl Dichlorine dioxide OCl 54.9
ClONO2 Chlorine nitrate OCl 26.6
HOClO Chlorous acid OClOH 32.3
FOOF Perfluoroperoxide OF 73.0
FNO3 Fluorine nitrate OF 36.7
H2O2 Hydrogen peroxide OH 38.2
H2O2+ Hydrogen peroxide cation OH 132.7
HOSH hydrogen thioperoxide OH 30.8
HOCH hydroxycarbene OH 118.7
NH2OH hydroxylamine OH 36.2
CH2OH Hydroxymethyl radical OH 11.6
CH3OH Methyl alcohol OH 5.7
CH3OH+ Methyl alcohol cation OH 0.6
HOCO Hydrocarboxyl radical OH 36.4
HNO2 Nitrous acid OH 53.3
O3H+ protonated ozone OH 36.4
HCOOH Formic acid OH 56.1
CH2NOH formaldoxime OH 36.2
CH2CHOH ethenol OH 19.1
CH3OOH Methyl peroxide OH 4.6
CH3CH2OH Ethanol OH 7.5
CH3OHH2O methanol water dimer OH 2.9
CH2FOH fluoromethanol OH 20.5
HNO3 Nitric acid OH 40.0
HOCH2CN cyanomethanol OH 9.2
CH3COOH Acetic acid OH 57.5
C3H4O allenol OH 15.0
CH3CHNOH Acetaldoxime OH 33.5
CH3CHOHCH3 Isopropyl alcohol OH 6.8
C3H7OH 1-Propanol OH 9.5
HClO3 Chloric Acid OH 24.1
HOONO2 peroxy nitric acid OH 14.9
H2SO4 Sulfuric acid OH 19.2
C3H4O2 propenalol OH 44.6
C4H10O Ethanol, 1,1-dimethyl- OH 6.6
C6H5OH phenol OH 11.1
CH3PH2 Methyl phosphine PH2 8.3
CH3SSCH3 Disulfide, dimethyl SCH3 46.2
ClSSCl Disulfur dichloride SCl 70.9
CH3SeH Methane selenol SeH 5.1
FSSF Difluorodisulfane SF 101.1
SF3 Sulfur trifluoride SF2 89.9
H2S2 Disulfane SH 35.8
CH3SH Methanethiol SH 5.9
HSSSH trisulfane SH 33.9
CH3CH2SH ethanethiol SH 7.4
C3H7SH 1-Propanethiol SH 7.4
Si2H6 disilane SiH3 4.0
SiH3CCl3 (trichloromethyl)silane SiH3 16.8
SiH3 Silyl radical SiH3 umbrella 235.5