National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 19April 2018
NIST Standard Reference Database 101
IIntroduction
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
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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

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IV.A.4. (XIV.F.)

Relative enthalpies of isomers - Comparison of 0K enthalpies (kJ mol-1)

Isomers of C6H8

2015 06 30 15:39
index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a C6H8 592574 1,3-Cyclohexadiene 0.0 sketch of 1,3-Cyclohexadiene
b C6H8 628411 1,4-Cyclohexadiene 2.5 sketch of 1,4-Cyclohexadiene
c C6H8 694019 Bicyclo[3.1.0]hex-2-ene   sketch of Bicyclo[3.1.0]hex-2-ene
d C6H8 821078 (E)-hexa-1,3,5-triene   sketch of (E)-hexa-1,3,5-triene
e C6H8 822413 Bicyclo[2.1.1]hex-2-ene   sketch of Bicyclo[2.1.1]hex-2-ene
f C6H8 930267 3-Methylenecyclopentene   sketch of 3-Methylenecyclopentene
g C6H8 2612466 (Z)-hexa-1,3,5-triene   sketch of (Z)-hexa-1,3,5-triene
h C6H8 30830207 Bicyclo[2.2.0]hex-1(4)-ene   sketch of Bicyclo[2.2.0]hex-1(4)-ene
i C6H8 59660649 (Z)-hexa-2,3,4-triene   sketch of (Z)-hexa-2,3,4-triene
j C6H8 59660650 (E)-hexa-2,3,4-triene   sketch of (E)-hexa-2,3,4-triene
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
composite G1
NC
NC
NC
NC
NC
NC
NC
NC
NC
G2MP2
NC
NC
NC
NC
NC
NC
NC
NC
NC
G2
NC
NC
NC
NC
NC
NC
NC
NC
NC
G3
NC
NC
NC
NC
NC
NC
NC
NC
NC
G3B3
NC
NC
NC
NC
NC
NC
NC
NC
NC
G3MP2
NC
NC
NC
NC
NC
NC
NC
NC
CBS-Q
NC
NC
NC

Methods with standard basis sets
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP Def2TZVPP cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
hartree fock HF
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
density functional LSDA
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC
     
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
NC
BLYP
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC
     
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
B1B95
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC
     
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC

NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC
B3LYP
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
B3LYPultrafine        
NC
NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
             
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
NC
 
B3PW91
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC
     
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
NC
mPW1PW91
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC
     
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
NC
M06-2X     0.0 a
2.4 b
52.7 c
80.1 d
110.1 e
6.8 f
83.8 g
295.4 h
153.7 i
153.5 j
 
NC
NC
NC
NC
NC
NC
NC
NC
NC
                         
PBEPBE
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
NC
PBEPBEultrafine        
NC
NC
NC
NC
NC
NC
NC
NC
NC
                         
PBE1PBE        
NC
NC
NC
NC
NC
NC
NC
NC
NC
                         
HSEh1PBE  
NC
NC
NC
NC
NC
NC
NC
NC
NC
   
NC
NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
NC
             
NC
NC
NC
NC
NC
NC
NC
NC
NC
     
TPSSh        
NC
NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
NC
   
NC
NC
NC
NC
NC
NC
NC
NC
NC
       
NC
NC
NC
NC
NC
NC
NC
NC
NC
     
wB97X-D    
NC
NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
   
NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
NC
 
B97D3  
NC
NC
NC
NC
NC
NC
NC
NC
NC
   
NC
NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
NC
  0.0 a
2.4 b
59.1 c
29.0 d
150.8 e
-0.4 f
36.3 g
280.1 h
107.3 i
107.2 j
     
NC
NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC
NC
 
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP Def2TZVPP cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
Moller Plesset perturbation MP2
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC

NC
NC

NC
NC
 
MP2=FULL  
NC
NC

NC
NC

NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC

NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC
       
NC
NC
NC

NC
NC
NC
     
MP3        
NC
NC
NC
NC
NC
NC
NC
NC
NC
                         
MP3=FULL        
NC
NC
NC
NC
NC
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
                     
B2PLYP        
NC
NC
NC
NC
NC
NC
NC
NC
NC
                 
NC
NC
NC
NC
NC
NC
NC
NC
NC
     
B2PLYP=FULLultrafine        
NC
NC
NC
NC
NC
NC
NC
                         
Configuration interaction CID  
NC
NC

NC
NC
 
NC
NC
NC
   
NC
NC
                   
CISD  
NC
NC

NC
NC
 
NC
NC
NC
   
NC
NC
                   
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP Def2TZVPP cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
Quadratic configuration interaction QCISD  
NC
NC
NC

NC
NC
NC

NC
NC

NC
NC
NC

NC
NC
NC
NC
NC

NC
NC
NC
NC

NC
NC
NC

NC
NC
       
NC
NC
       
Coupled Cluster CCD  
NC
NC
NC

NC
NC
NC

NC
NC

NC
NC
NC
NC

NC
NC
NC

NC
NC
NC

NC
NC
NC
         
NC
NC
       
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP Def2TZVPP cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z

Methods with effective core potentials (select basis sets)
daug-cc-pVDZ daug-cc-pVTZ daug-cc-pVQZ Sadlej_pVTZ CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF        
-97962.3 b
-97893.5 c
-97917.6 d
-97811.9 e
-97963.5 f
-97909.4 g
-97642.4 h
-97779.9 i
-97779.9 j

-98213.9 b
-98167.7 c
-98153.4 d
-98092.9 e
-98212.8 f
-98144.8 g
-97933.2 h
-98022.5 i
-98022.8 j

-98009.2 b
-97931.9 c
-97963.2 d
-97845.7 e
-98008.5 f
-97954.8 g
-97683.2 h
-97856.4 i
-97856.6 j

-98277.1 b
-98214.5 c
-98221.5 d
-98130.5 e
-98273.2 f
-98212.6 g
-97983.1 h
-98119.5 i
-98119.7 j

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC
density functional B1B95        
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
       
B3LYP        
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC
Moller Plesset perturbation MP2        
-99205.9 b
-99150.8 c
-99168.0 d
-99087.2 e
-99217.4 f
-99161.9 g
-98925.0 h
-99051.6 j

NC
NC
NC
NC
NC
NC
-99864.0 h
-99918.0 i
-99918.9 j

-99389.6 b
-99333.5 c
-99353.3 d
-99267.0 e
-99398.7 f
-99349.6 g
-99100.2 h
-99256.2 i

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
NC

Single point energy calculations (select basis sets)
cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
Moller Plesset perturbation MP2FC// HF/6-31G*
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
   
NC
NC
NC
NC
NC
NC
NC
NC
MP2FC// B3LYP/6-31G*
NC
NC
NC
NC
NC
NC
NC
NC
       
MP2FC// MP2FC/6-31G*
NC
NC
NC
 
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
NC
NC
NC
NC
NC
NC
 
Coupled Cluster CCSD// MP2FC/6-31G*      
NC
NC
NC
NC
NC
NC
NC
NC
 
CCSD(T)// MP2FC/6-31G*      
NC
NC
NC
NC
NC
NC
NC
NC
 
NC = not calculated
For descriptions of the methods (AM1, HF, MP2, ...) and basis sets (3-21G, 3-21G*, 6-31G, ...) see the glossary in section I.C. Predefined means the basis set used is determined by the method.
gaw refers to the group additivity method implemeted in the NIST Chemistry Webbook.

See section III.C.1 List or set vibrational scaling factors to change the scale factors used here.
See section III.C.2 Calculate a vibrational scaling factor for a given set of molecules to determine the least squares best scaling factor.