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Relative enthalpies of isomers - Comparison of 298.15K enthalpies (kJ mol-1)

Isomers of C7H8

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a C7H8 544252 cycloheptatriene   sketch of cycloheptatriene
b C6H5CH3 108883 toluene 0.0 sketch of toluene
c C7H8 121460 Norbornadiene 190.0 sketch of Norbornadiene
d C7H8 278068 Quadricyclane 286.0 sketch of Quadricyclane
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical AM1
0.0 b
PM3
0.0 b
525.8 c
PM6
0.0 b
MNDOd
0.0 b
composite G1
0.0 b
195.8 c
G2MP2
0.0 b
188.4 c
G2
0.0 b
145.3 c
G3
0.0 b
150.9 c
-71.9 d
G3B3
0.0 b
146.6 c
G3MP2
0.0 b
193.8 c
G4
0.0 b
189.6 c
CBS-Q
NC
NC
molecular mechanics MM3
0.0 b

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 cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z daug-cc-pVTZ
hartree fock HF
0.0 b
143.9 c

NC

NC

0.0 b
262.2 c

0.0 b
231.0 c

0.0 b
231.3 c

0.0 b
233.6 c

NC

0.0 b
228.7 c

0.0 b
229.0 c

0.0 b

0.0 b
233.1 c

0.0 b
230.2 c

0.0 b
233.9 c

NC

0.0 b
234.1 c

0.0 b

0.0 b
234.2 c
density functional LSDA        
NC
                         
BLYP
NC

0.0 b
201.8 c

0.0 b
201.8 c

0.0 b
255.1 c

0.0 b
239.2 c

0.0 b
238.2 c

0.0 b
238.3 c

0.0 b
238.2 c

  c

0.0 b
236.5 c
   
NC

0.0 b
243.5 c

0.0 b
 
0.0 b
 
B1B95
0.0 b
148.0 c

0.0 b
159.5 c

0.0 b
159.5 c

0.0 b
216.5 c

0.0 b
193.6 c

0.0 b
198.8 c

0.0 b
198.8 c

0.0 b
195.4 c

0.0 b
195.1 c

0.0 b
195.7 c
   
0.0 b
193.9 c

0.0 b
192.0 c

0.0 b
194.5 c

0.0 b

0.0 b
 
B3LYP
0.0 b
166.8 c

0.0 b
196.8 c

0.0 b
196.8 c

0.0 b
251.3 c

0.0 b
232.9 c

0.0 b
232.2 c

0.0 b
232.6 c

0.0 b
231.8 c

0.0 b
231.2 c

0.0 b
231.4 c

0.0 b

0.0 b
236.1 c

0.0 b
227.3 c

0.0 b
237.5 c

NC

0.0 b
237.3 c

0.0 b
 
B3LYPultrafine        
0.0 b
                   
0.0 b
237.3 c
   
B3PW91
NC

0.0 b
173.5 c

0.0 b
173.5 c

0.0 b
230.6 c

0.0 b
212.3 c

0.0 b
211.8 c

0.0 b
211.6 c

0.0 b
209.6 c

0.0 b
209.3 c

0.0 b
210.7 c
   
NC

0.0 b
214.8 c

0.0 b
 
0.0 b
 
mPW1PW91
0.0 b
152.1 c

0.0 b
162.5 c

0.0 b
168.3 c

0.0 b
226.3 c

0.0 b
201.7 c

0.0 b
201.3 c

0.0 b
201.3 c

0.0 b
199.2 c

0.0 b
204.6 c

0.0 b
205.9 c
   
0.0 b
196.6 c

0.0 b
204.5 c

0.0 b
 
0.0 b
 
M06-2X    
  c
 
  c
                         
PBEPBE
NC

0.0 b
168.4 c

0.0 b
168.4 c

0.0 b
226.6 c

0.0 b
210.4 c

0.0 b
209.6 c

0.0 b
209.0 c

0.0 b
207.0 c

0.0 b
206.5 c

0.0 b
207.3 c
   
NC

0.0 b
211.4 c
   
0.0 b
 
PBEPBEultrafine        
0.0 b
210.3 c
                         
PBE1PBE        
0.0 b
203.8 c
                         
HSEh1PBE  
0.0 b
169.9 c
   
0.0 b
208.4 c
 
0.0 b
207.8 c
           
0.0 b
211.0 c
       
TPSSh        
0.0 b
209.0 c
 
0.0 b
208.0 c
   
0.0 b
207.1 c
     
0.0 b
210.9 c
       
wB97X-D    
0.0 b
171.4 c
 
0.0 b
206.3 c
 
0.0 b
205.8 c
 
0.0 b
203.4 c
   
0.0 b
207.5 c

0.0 b
205.8 c

0.0 b
207.0 c
 
0.0 b
206.9 c
   
B97D3  
  c
   
  c
 
  c
 
  c
 
  c

  c
 
  c
 
  c
   
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 cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z daug-cc-pVTZ
Moller Plesset perturbation MP2
NC

0.0 b
177.4 c

0.0 b
177.4 c

0.0 b
226.4 c

0.0 b
197.8 c

NC

NC

0.0 b
188.1 c

0.0 b
185.1 c

0.0 b
188.1 c
 
0.0 b
186.4 c

0.0 b
190.5 c

0.0 b
195.8 c
 
0.0 b
   
MP2=FULL
NC

0.0 b
177.1 c

0.0 b
177.1 c

0.0 b
225.9 c

0.0 b
196.4 c

NC

NC

NC

0.0 b
184.0 c

NC
   
NC

  c
       
MP3        
0.0 b
192.5 c
                         
MP3=FULL        
0.0 b
191.2 c
 
0.0 b
193.6 c
                     
MP4  
NC
                               
B2PLYP        
0.0 b
218.8 c
               
0.0 b
221.3 c
       
Configuration interaction CID  
0.0 b
179.3 c

NC

NC

NC
   
NC
                   
CISD  
0.0 b
179.3 c

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 cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z daug-cc-pVTZ
Quadratic configuration interaction QCISD  
0.0 b
161.8 c

0.0 b
161.8 c

0.0 b
212.8 c

NC

NC

NC

NC
       
NC
         
QCISD(T)        
NC
                         
Coupled Cluster CCD  
0.0 b
162.0 c

0.0 b
162.0 c

0.0 b
213.0 c

0.0 b
189.5 c

NC

NC

NC
       
NC
         
CCSD(T)        
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 cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z daug-cc-pVTZ

Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD cc-pVTZ-PP aug-cc-pVTZ-PP Def2TZVPP
hartree fock HF
NC

NC

0.0 b
242.4 c

0.0 b
215.1 c

0.0 b
254.9 c

0.0 b
254.0 c
   
0.0 b
234.7 c
density functional B1B95
0.0 b

0.0 b
             
B3LYP
NC

NC

NC

NC

NC

NC
   
0.0 b
237.3 c
PBEPBE                
0.0 b
211.3 c
Moller Plesset perturbation MP2
0.0 b
203.8 c

0.0 b
169.5 c

0.0 b
194.6 c

NC

0.0 b
212.1 c

0.0 b
211.2 c
   
0.0 b
194.7 c

Single point energy calculations (select basis sets)
6-311+G(3df,2p) aug-cc-pVDZ
Moller Plesset perturbation MP2FC// MP2FC/6-31G*
0.0 b

0.0 b
MP4// MP2/6-31G*
0.0 b
 
Coupled Cluster CCSD// MP2FC/6-31G*
0.0 b
 
CCSD(T)// MP2FC/6-31G*
0.0 b
 
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 Calculated; Vibrations; Scale Factors; Scale factors to list vibrational scaling factors.
See section Calculated; Vibrations; Scale Factors; Calculate a scale factor to calculate a vibrational scaling factor for a given set of molecules.