National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 22May 2022
NIST Standard Reference Database 101
IIntroduction
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
VIInput and output files
VIITutorials and Units
VIIILinks to other sites
IXFeedback
XOlder CCCBDB versions
XIIGeometries
XIII Vibrations
XIVReaction data
XVEntropy data
XVIBibliographic data
XVIIIon data
XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers
XXIOddities

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.

return to home page

IV.D.8.

Average Bond Length Differences by Model Chemistry

Calculated at CCSD(T)=FULL/TZVP

Species Name Bond type Bond Length (Å)
Experimental unc. Calculated Difference atom1 atom2
C4H10O Methyl propyl ether rCC 1.530   1.094 -0.436 5 13
C5H8O Methyl cyclopropyl ketone rCH 1.126   1.089 -0.037 3 7
C2H2O2 Ethanedial rCH 1.132   1.103 -0.029 1 3
CH3CH2CH2CH3 Butane rCH 1.117   1.097 -0.020 1 5
LiOH lithium hydroxide rOH 0.969   0.951 -0.018 1 3
C4H8O2 Ethyl acetate rCH 1.105   1.088 -0.017 1 7
C3F6 hexafluoropropene rCF 1.329 ±0.003 1.313 -0.016 1 4
C5H8 Ethenylcyclopropane rCH 1.099   1.085 -0.014 1 6
B2H6 Diborane rBH 1.200   1.187 -0.013 1 5
H2Cl+ dihydrogen monochloride cation rHCl 1.321 ±0.000 1.309 -0.012 1 2
CH3CH2CHO Propanal rCH 1.103   1.091 -0.012 1 6
SiH2Cl2 dichlorosilane rSiH 1.480 ±0.015 1.468 -0.012 1 2
HSe Selenium monohydride rSeH 1.475 ±0.010 1.465 -0.010 1 2
HF+ hydrogen fluoride cation rHF 1.014   1.004 -0.010 1 2
CH2NH Methanimine rCH 1.103   1.093 -0.010 1 3
HCCl Chloromethylene rCH 1.119 ±0.036 1.111 -0.008 1 3
ScH Scandium monohydride rScH 1.775 ±0.000 1.768 -0.008 1 2
CH3CH2CHO Propanal rCH 1.105   1.097 -0.008 2 8
B2H6 Diborane rBH 1.320   1.313 -0.007 1 3
CH3CH2CHO Propanal rCH 1.115   1.108 -0.007 3 10
CH2 Methylene rCH 1.085   1.078 -0.007 1 2
CH2PH Phosphaethene rCH 1.090 ±0.015 1.083 -0.007 1 3
AsH Arsenic monohydride rAsH 1.535 ±0.001 1.528 -0.007 1 2
HeH+ Helium hydride cation rHHe 0.790   0.784 -0.006 1 2
CH3CHO Acetaldehyde rCH 1.114   1.108 -0.006 1 4
ArH+ Argon hydride cation rArH 1.292 ±0.000 1.286 -0.006 1 2
HOCl hypochlorous acid rOH 0.973 ±0.002 0.968 -0.005 1 2
CH2PH Phosphaethene rCH 1.090 ±0.015 1.085 -0.005 1 4
HClO4 perchloric acid rOH 0.980   0.975 -0.005 3 6
H2CSe Selenoformaldehyde rHC 1.090   1.086 -0.005 1 3
C2H Ethynyl radical rC#C 1.217   1.212 -0.004 1 2
CH2CO Ketene rCH 1.083   1.078 -0.004 1 4
CH3CCH propyne rCH 1.096   1.092 -0.004 1 5
HS+ sulfur monohydride cation rSH 1.374   1.370 -0.004 1 2
CH3CH2CHO Propanal rCH 1.096   1.092 -0.004 1 5
HSiCl Chlorosilylene rSiH 1.525 ±0.005 1.521 -0.004 1 3
NH4+ ammonium cation rHN 1.029 ±0.000 1.025 -0.004 1 2
C5H6 Propellane rCC 1.525 ±0.002 1.521 -0.004 1 2
CH3NH2 methyl amine rNH 1.018 ±0.001 1.014 -0.004 2 6
KrH+ Protonated Krypton rHKr 1.421 ±0.000 1.418 -0.004 1 2
CrH Chromium hydride rHCr 1.655 ±0.001 1.652 -0.003 1 2
C2H2O2 Ethanedial rCC 1.526   1.523 -0.003 1 2
CH3NH2 methyl amine rCN 1.471 ±0.003 1.468 -0.003 1 2
CH3NO nitrosomethane rCH 1.094   1.091 -0.003 1 4
CHF3 Methane, trifluoro- rCH 1.091 ±0.014 1.088 -0.003 1 2
CH3CH2CH2CH3 Butane rCC 1.531   1.529 -0.002 1 2
HBr+ hydrogen bromide cation rHBr 1.448   1.446 -0.002 1 2
CH2CHCH2CH3 1-Butene rCC 1.536   1.534 -0.002 1 2
CH3CHFCH3 2-Fluoropropane rCH 1.093 ±0.006 1.091 -0.002 4 8
CH2Cl2 Methylene chloride rCH 1.085 ±0.002 1.083 -0.002 1 2
C2H2ClF 1-chloro-1-fluoroethylene rCH 1.082 ±0.001 1.081 -0.001 2 5
CH3CHFCH3 2-Fluoropropane rCH 1.094 ±0.005 1.093 -0.001 4 10
BH3 boron trihydride rBH 1.190   1.189 -0.001 1 2
HBr hydrogen bromide rHBr 1.414 ±0.000 1.413 -0.001 1 2
BH Boron monohydride rBH 1.232   1.231 -0.001 1 2
H2Se Hydrogen selenide rSeH 1.460   1.459 -0.001 1 2
CH3OC2H5 Ethane, methoxy- rCO 1.415 ±0.005 1.414 -0.001 1 2
C3H8 Propane rCH 1.096   1.095 -0.001 1 4
SiH3F monofluorosilane rSiH 1.476   1.475 -0.001 1 3
CH3OC2H5 Ethane, methoxy- rCH 1.099 ±0.007 1.098 -0.001 1 6
C3H6 Cyclopropane rCH 1.083   1.082 -0.001 1 4
C4H8O2 Ethyl acetate rCC 1.515   1.515 0.000 5 6
CH3OC2H5 Ethane, methoxy- rCH 1.092 ±0.007 1.092 0.000 4 11
SiH3Cl chlorosilane rSiH 1.475   1.475 0.000 1 3
CH3NO nitrosomethane rCH 1.092   1.092 0.000 1 5
C4H8 cyclobutane rCH 1.093   1.093 0.000 1 5
C4H8O2 Ethyl acetate rCC 1.508   1.508 0.000 1 2
CH2CHF Ethene, fluoro- rCH 1.082   1.082 0.000 1 4
C2H2 Acetylene rCH 1.063   1.064 0.001 1 3
C2H2+ acetylene cation rC=C 1.253 ±0.001 1.253 0.001 1 2
C3H4 cyclopropene rCH 1.088   1.089 0.001 1 6
CH3OC2H5 Ethane, methoxy- rCH 1.100 ±0.003 1.101 0.001 3 8
SiH4 Silane rSiH 1.480 ±0.000 1.480 0.001 1 2
BeH2 beryllium dihydride rBeH 1.326 ±0.000 1.327 0.001 1 2
C5H6 Propellane rCC 1.596 ±0.005 1.597 0.001 2 5
NH2SH Thiohydroxylamine rSH 1.344 ±0.029 1.345 0.001 2 3
NO Nitric oxide rN=O 1.154 ±0.000 1.155 0.001 1 2
C4H8 cyclobutane rCH 1.091   1.092 0.001 1 6
CF3COOH trifluoroacetic acid rCC 1.546 ±0.005 1.547 0.001 1 2
H2 Hydrogen diatomic rHH 0.741   0.743 0.001 1 2
OCSe Carbonyl selenide rC=O 1.159   1.160 0.001 1 2
CH3CH2CHO Propanal rCC 1.523   1.524 0.001 1 2
CH Methylidyne rCH 1.120   1.122 0.002 1 2
C3H3NO Oxazole rCH 1.075 ±0.001 1.077 0.002 4 7
C3H3NO Oxazole rCH 1.073 ±0.001 1.075 0.002 5 8
C3H3NO Oxazole rCH 1.075 ±0.001 1.077 0.002 2 6
BeH beryllium monohydride rBeH 1.343   1.345 0.002 1 2
CH3CH2CHO Propanal rCC 1.509   1.511 0.002 2 3
C2H2+ acetylene cation rCH 1.077 ±0.005 1.079 0.002 1 3
CH4 Methane rCH 1.087 ±0.001 1.089 0.002 1 2
C3H3NO Oxazole rCO 1.357 ±0.003 1.360 0.002 1 2
CH3CHFCH3 2-Fluoropropane rCH 1.092   1.095 0.003 1 3
CH3Br methyl bromide rCH 1.082 ±0.001 1.085 0.003 1 3
CH3CCH propyne rCH 1.060   1.063 0.003 3 4
C3H4 cyclopropene rCH 1.072   1.075 0.003 2 4
AsH3 Arsine rAsH 1.511 ±0.000 1.514 0.003 1 2
N3 azide radical rNN 1.181   1.185 0.003 1 2
GeH germylidene rGeH 1.588   1.591 0.003 1 2
CH3CHO Acetaldehyde rCH 1.086   1.090 0.004 2 5
CH3OC2H5 Ethane, methoxy- rCH 1.086 ±0.010 1.090 0.004 1 5
H2O Water rOH 0.958 ±0.000 0.962 0.004 1 2
C5H8 Ethenylcyclopropane rCC 1.475   1.479 0.004 1 2
SiH+ silicon monohydride cation rSiH 1.504   1.508 0.004 1 2
C3F6 hexafluoropropene rC=C 1.329 ±0.003 1.333 0.004 1 2
CH3OC2H5 Ethane, methoxy- rCH 1.089 ±0.008 1.093 0.004 4 10
HO2 Hydroperoxy radical rOH 0.971   0.975 0.004 1 3
HF Hydrogen fluoride rHF 0.917 ±0.000 0.921 0.004 1 2
CO+ carbon monoxide cation rC=O 1.115 ±0.000 1.120 0.004 1 2
CH2CHF Ethene, fluoro- rCH 1.077   1.081 0.004 2 5
C4H6 Bicyclo[1.1.0]butane rCC 1.497   1.502 0.005 1 2
He2+ helium diatomic cation rHeHe 1.081 ±0.001 1.086 0.005 1 2
HCl+ hydrogen chloride cation rHCl 1.315   1.320 0.005 1 2
C5H8O Methyl cyclopropyl ketone rCC 1.510   1.515 0.005 2 3
CF Fluoromethylidyne rCF 1.276   1.281 0.005 1 2
SiH2F2 difluorosilane rSiH 1.462   1.467 0.005 1 4
CH2CO Ketene rC=O 1.162   1.167 0.005 2 3
HNCNH diiminomethane rC=N 1.224 ±0.001 1.229 0.005 1 2
C3H3NO Oxazole rCO 1.370 ±0.002 1.375 0.005 1 5
FNO2 Nitryl fluoride rN=O 1.180 ±0.005 1.185 0.005 1 3
CH3CHFCH3 2-Fluoropropane rCH 1.088 ±0.006 1.093 0.005 4 6
CH3NH2 methyl amine rCH 1.093 ±0.000 1.098 0.005 1 3
SiH3+ Silyl cation rSiH 1.460 ±0.010 1.465 0.005 1 2
NO+ nitric oxide cation rN=O 1.066   1.071 0.005 1 2
CN- cyanide anion rC#N 1.177 ±0.004 1.182 0.005 1 2
OH Hydroxyl radical rOH 0.970   0.975 0.006 1 2
C2 Carbon diatomic rC=C 1.243   1.248 0.006 1 2
C2H3 vinyl rCH 1.085   1.091 0.006 2 4
OH- hydroxide anion rOH 0.964   0.970 0.006 1 2
B2 Boron diatomic rBB 1.590   1.596 0.006 1 2
HCl Hydrogen chloride rHCl 1.275 ±0.000 1.281 0.006 1 2
CH2F2 Methane, difluoro- rCH 1.084 ±0.003 1.090 0.006 1 2
HOBr Hypobromous acid rOH 0.961   0.968 0.007 1 2
C2H2 Acetylene rC#C 1.203   1.209 0.007 1 2
N2 Nitrogen diatomic rN#N 1.098   1.105 0.007 1 2
NH3BF3 Amminetrifluoroboron rBN 1.673   1.680 0.007 1 2
C4H8O2 Ethyl acetate rC=O 1.203   1.210 0.007 2 4
CO Carbon monoxide rC#O 1.128 ±0.000 1.135 0.007 1 2
BF Boron monofluoride rBF 1.267 ±0.000 1.274 0.007 1 2
GeH3F monofluorogermane rGeH 1.515 ±0.000 1.522 0.008 1 3
HS Mercapto radical rSH 1.341   1.348 0.008 1 2
CF3COOH trifluoroacetic acid rC=O 1.192 ±0.003 1.200 0.008 2 4
BF3 Borane, trifluoro- rBF 1.307   1.315 0.008 1 2
SiH Silylidyne rSiH 1.520   1.528 0.008 1 2
C3H6 Cyclopropane rCC 1.501   1.509 0.008 1 2
CHF3 Methane, trifluoro- rCF 1.328 ±0.003 1.337 0.009 1 3
O2+ diatomic oxygen cation rOO 1.116   1.125 0.009 1 2
CH2F2 Methane, difluoro- rCF 1.351 ±0.001 1.360 0.009 1 4
C4H8O2 Ethyl acetate rCO 1.345   1.354 0.009 2 3
HS- mercapto anion rSH 1.343   1.352 0.009 1 2
PO Phosphorus monoxide rP=O 1.476   1.485 0.009 1 2
BN boron nitride rB=N 1.325   1.335 0.010 1 2
PH phosphorus monohydride rPH 1.422   1.432 0.010 1 2
TiCl Titanium Monochloride rClTi 2.265 ±0.000 2.275 0.010 1 2
O2 Oxygen diatomic rO=O 1.208   1.218 0.010 1 2
BO boron monoxide rB=O 1.205   1.215 0.010 1 2
LiH Lithium Hydride rLiH 1.595 ±0.000 1.605 0.010 1 2
OCSe Carbonyl selenide rC=Se 1.709   1.719 0.010 1 3
CH2CHCH2CH3 1-Butene rCC 1.493   1.504 0.011 2 3
CSe2 Carbon diselenide rC=Se 1.692 ±0.000 1.704 0.011 1 2
CH3OC2H5 Ethane, methoxy- rCO 1.407 ±0.004 1.418 0.011 2 3
SCSe Carbon sulfide selenide rC=Se 1.695 ±0.002 1.707 0.012 1 3
CSe Carbon monoselenide rC=Se 1.676 ±0.000 1.688 0.012 1 2
MgH magnesium monohydride rMgH 1.730   1.741 0.012 1 2
H2CSe Selenoformaldehyde rC=Se 1.753   1.765 0.012 1 2
CH3CSNH2 Ethanethioamide rC=S 1.647 ±0.002 1.659 0.012 1 2
CBr4 Carbon tetrabromide rCBr 1.942 ±0.002 1.955 0.013 1 2
FNO2 Nitryl fluoride rNF 1.467 ±0.015 1.480 0.013 1 2
SCSe Carbon sulfide selenide rC=S 1.553 ±0.002 1.566 0.013 1 2
HO2 Hydroperoxy radical rOO 1.331   1.344 0.014 1 2
FO Oxygen monofluoride rFO 1.354   1.369 0.015 1 2
LiNH2 lithium amide rLiN 1.736 ±0.003 1.751 0.015 1 2
SiC silicon monocarbide rCSi 1.722   1.737 0.015 1 2
SeO2 Selenium dioxide rSeO 1.607 ±0.001 1.624 0.017 1 2
HNO3 Nitric acid rNO 1.406   1.423 0.017 1 2
C2H Ethynyl radical rCH 1.047   1.064 0.018 1 3
GaF Gallium monofluoride rFGa 1.774 ±0.000 1.792 0.018 1 2
C3H5 Allyl radical rCH 1.069   1.087 0.018 1 2
GeF+ Germanium monofluoride cation rFGe 1.665 ±0.000 1.684 0.019 1 2
H2CS Thioformaldehyde rC=S 1.611   1.630 0.019 1 2
CH2Cl2 Methylene chloride rCCl 1.767 ±0.002 1.786 0.019 1 4
SeO Selenium monoxide rSeO 1.639 ±0.001 1.658 0.019 1 2
GeH3F monofluorogermane rGeF 1.731 ±0.000 1.750 0.019 1 2
GeO Germanium monoxide rOGe 1.625   1.644 0.019 1 2
C3O2 Carbon suboxide rC=O 1.146   1.166 0.020 2 4
F2 Fluorine diatomic rFF 1.412   1.432 0.020 1 2
NaH sodium hydride rNaH 1.887 ±0.000 1.907 0.020 1 2
LiOH lithium hydroxide rLiO 1.582   1.602 0.021 1 2
AlCl Aluminum monochloride rAlCl 2.130 ±0.000 2.151 0.021 1 2
HCCl Chloromethylene rCCl 1.696 ±0.003 1.717 0.021 1 2
CH3Br methyl bromide rCBr 1.934 ±0.000 1.956 0.022 1 2
SiP Silicon monophosphide rSiP 2.078 ±0.002 2.100 0.022 1 2
GeF Germanium monofluoride rFGe 1.745   1.768 0.023 1 2
PN Phosphorus mononitride rP#N 1.491   1.515 0.024 1 2
C3O2 Carbon suboxide rC=C 1.251   1.276 0.025 1 2
AlC Aluminum carbide rC=Al 1.955   1.980 0.025 1 2
GaBr Gallium monobromide rGaBr 2.352 ±0.000 2.378 0.026 1 2
SiH3Cl chlorosilane rSiCl 2.051   2.077 0.027 1 2
GeCl Germanium monochloride rClGe 2.164 ±0.000 2.191 0.027 1 2
GeS Germanium monosulfide rS=Ge 2.012 ±0.000 2.039 0.027 1 2
AlNC Aluminum isocyanide rAlN 1.855 ±0.005 1.882 0.027 1 2
C5H8O Cyclopentanone rCC 1.504   1.531 0.027 2 3
AsF Arsenic monofluoride rFAs 1.736 ±0.001 1.765 0.029 1 2
C2H6O2S Dimethyl sulfone rCS 1.777 ±0.006 1.806 0.029 1 4
SiO Silicon monoxide rSiO 1.510 ±0.000 1.538 0.029 1 2
As4 Arsenic tetramer rAsAs 2.435   2.464 0.029 1 2
SiH2Cl2 dichlorosilane rSiCl 2.033 ±0.003 2.062 0.029 1 4
SiS silicon monosulfide rSiS 1.929 ±0.000 1.959 0.029 1 2
BeO beryllium oxide rBe=O 1.331   1.362 0.031 1 2
NS Mononitrogen monosulfide rNS 1.497 ±0.000 1.528 0.031 1 2
SiH3F monofluorosilane rSiF 1.595   1.626 0.031 1 2
NaF sodium fluoride rNaF 1.926 ±0.000 1.957 0.031 1 2
HOBr Hypobromous acid rBrO 1.834   1.865 0.031 2 3
Li2 Lithium diatomic rLiLi 2.673   2.706 0.033 1 2
AlF Aluminum monofluoride rAlF 1.654 ±0.000 1.687 0.033 1 2
SiBr+ Silicon monobromide cation rSiBr 2.095 ±0.000 2.129 0.033 1 2
P2 Phosphorus diatomic rP#P 1.893   1.927 0.034 1 2
SOF4 Sulfur tetrafluoride oxide rFS 1.596 ±0.003 1.630 0.034 1 3
SiCl Clorosilylidyne rSiCl 2.061 ±0.000 2.096 0.034 1 2
HSiCl Chlorosilylene rSiCl 2.067 ±0.003 2.102 0.035 1 2
ClO Monochlorine monoxide rClO 1.596 ±0.001 1.631 0.035 1 2
SiF silicon monofluoride rSiF 1.604   1.640 0.036 1 2
SiF2 Silicon difluoride rFSi 1.590 ±0.000 1.626 0.036 1 2
HOCl hypochlorous acid rClO 1.697 ±0.001 1.733 0.036 1 3
SF4 Sulfur tetrafluoride rSF 1.646 ±0.003 1.682 0.036 1 2
PF2 Phosphorus difluoride rPF 1.579   1.615 0.036 1 2
F2SO Thionyl Fluoride rO=S 1.413 ±0.000 1.449 0.036 1 2
SeCl2 Selenium Dichloride rClSe 2.157 ±0.003 2.194 0.037 1 2
SO+ sulfur monoxide cation rO=S 1.424   1.461 0.037 1 2
SF4 Sulfur tetrafluoride rSF 1.545 ±0.003 1.582 0.037 1 4
PS phosphorus sulfide rP=S 1.900   1.939 0.039 1 2
SF Monosulfur monofluoride rSF 1.599   1.639 0.040 1 2
Se2 Selenium diatomic rSe=Se 2.166 ±0.001 2.206 0.040 1 2
BrF Bromine monofluoride rFBr 1.759 ±0.000 1.799 0.040 1 2
SO Sulfur monoxide rS=O 1.481   1.522 0.041 1 2
LiCl lithium chloride rLiCl 2.021 ±0.000 2.062 0.041 1 2
NaCl Sodium Chloride rNaCl 2.361 ±0.000 2.403 0.043 1 2
SOF4 Sulfur tetrafluoride oxide rFS 1.539 ±0.003 1.582 0.043 1 5
GaAs Gallium arsenide rGa#As 2.530 ±0.020 2.573 0.043 1 2
HClO4 perchloric acid rO=Cl 1.414 ±0.001 1.457 0.043 1 2
LiO lithium oxide rLiO 1.688   1.732 0.044 1 2
LiF lithium fluoride rLiF 1.564 ±0.000 1.608 0.044 1 2
BrO Bromine monoxide rOBr 1.718   1.762 0.045 1 2
LiBr Lithium Bromide rLiBr 2.170 ±0.000 2.215 0.045 1 2
S2 Sulfur diatomic rS=S 1.889   1.934 0.045 1 2
C2H6O2S Dimethyl sulfone rS=O 1.431 ±0.004 1.476 0.045 1 2
SSO Disulfur monoxide rS=O 1.456   1.502 0.046 1 2
HSSSH trisulfane rSS 2.054 ±0.000 2.100 0.046 1 2
CFCl chlorofluoromethylene rCCl 1.714   1.760 0.046 1 3
ClF Chlorine monofluoride rFCl 1.628 ±0.000 1.675 0.046 1 2
F2SO Thionyl Fluoride rFS 1.585 ±0.000 1.633 0.048 1 3
SCl2 Sulfur dichloride rSCl 2.013 ±0.001 2.067 0.054 1 2
SSO Disulfur monoxide rS=S 1.884   1.939 0.055 2 3
Br2 Bromine diatomic rBrBr 2.281   2.337 0.056 1 2
BrCl Bromine monochloride rClBr 2.136 ±0.000 2.194 0.058 1 2
SCl sulfur monochloride rSCl 1.975   2.035 0.059 1 2
ClOF3 Chlorine trifluoride oxide rFCl 1.713 ±0.003 1.774 0.061 1 4
Cl2 Chlorine diatomic rClCl 1.988   2.049 0.062 1 2
HClO4 perchloric acid rO=Cl 1.404 ±0.001 1.468 0.064 1 4
C4H8O2 Ethyl acetate rCO 1.448   1.515 0.067 5 6
HClO4 perchloric acid rOCl 1.641 ±0.002 1.708 0.067 1 3
NaLi lithium sodium rLiNa 2.889   2.960 0.071 1 2
ClOF3 Chlorine trifluoride oxide rFCl 1.603 ±0.004 1.692 0.089 1 3
KH Potassium hydride rKH 2.243 ±0.001 2.374 0.132 1 2
CaH Calcium monohydride rCaH 2.003 ±0.000 2.170 0.167 1 2
Al2Cl6 Aluminum, di-μ-chlorotetrachlorodi- rAlCl 2.040 ±0.040 2.274 0.234 1 3
C4H10O Methyl propyl ether rCH 1.099   1.415 0.316 1 2
CaO Calcium monoxide rOCa 1.822   2.163 0.341 1 2
267 molecules.