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

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

Isomers of C6H6

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a C6H6 821089 Hexa-1,5-diene-3-yne   sketch of Hexa-1,5-diene-3-yne
b C6H6 29776963 1,2,4,5-Hexatetraene   sketch of 1,2,4,5-Hexatetraene
c C6H6 71432 Benzene 0.0 sketch of Benzene
d C6H6 497201 Fulvene 141.3 sketch of Fulvene
e C6H6 2809690 2,4-Hexadiyne 294.5 sketch of 2,4-Hexadiyne
f C6H6 3227905 Trimethylenecycopropane 313.1 sketch of Trimethylenecycopropane
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical AM1
0.0 c
170.0 d
252.8 e
593.5 f
PM3
0.0 c
135.8 d
230.9 e
314.9 f
PM6
0.0 c
119.3 d
252.2 e
250.9 f
MNDOd
0.0 c
135.4 d
203.4 e
composite G1
0.0 c
398.3 d
530.1 e
56.6 f
G2MP2
0.0 c
396.2 d
531.3 e
56.6 f
G2
0.0 c
396.7 d
531.4 e
56.1 f
G3
0.0 c
399.0 d
57.1 f
G3B3
0.0 c
-133.2 d
270.1 e
337.1 f
G3MP2
0.0 c
398.5 d
533.5 e
G4
0.0 c
125.1 d
271.8 e
340.7 f
CBS-Q
NC
Group additivity gaw
0.0 c
molecular mechanics MM3
0.0 c
114.0 d
509.2 e

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) cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
hartree fock HF
0.0 c
173.9 d
283.3 e

0.0 c
165.2 d
267.2 e

0.0 c
165.2 d
267.2 e

0.0 c
165.6 d
291.7 e
 
0.0 c
149.4 d
288.4 e

0.0 c
292.8 e

0.0 c
145.5 d
273.4 e

0.0 c
144.3 d
276.9 e

0.0 c
270.6 e

0.0 c
141.8 d

0.0 c
145.7 d
291.0 e

0.0 c
142.5 d
274.6 e

0.0 c
142.6 d

0.0 c
142.0 d
275.1 e

0.0 c
142.5 d
274.6 e
density functional LSDA
0.0 c
171.6 d

0.0 c
159.1 d

0.0 c
159.1 d

0.0 c
154.4 d
330.6 e

0.0 c
146.4 d
329.6 e

0.0 c
146.0 d
331.5 e

0.0 c
143.7 d
330.1 e

0.0 c
146.5 d
311.7 e

0.0 c
145.0 d
315.4 e

0.0 c
144.2 d
320.0 e
 
0.0 c
144.7 d
336.8 e

0.0 c
144.6 d
317.3 e

0.0 c
143.0 d
 
0.0 c
144.6 d
317.3 e
BLYP
0.0 c
318.9 e

0.0 c
147.8 d
255.1 e

NC

0.0 c
145.3 d
266.7 e

0.0 c
138.7 d
265.6 e

0.0 c
138.4 d
268.1 e

0.0 c
135.6 d
265.7 e

NC

0.0 c
136.8 d
249.6 e

0.0 c
253.5 e
 
0.0 c
137.9 d
273.6 e

NC
NC

0.0 c
 
NC
NC
B1B95
0.0 c
338.9 e

0.0 c
289.2 e

0.0 c
289.2 e

0.0 c
298.5 e

0.0 c
299.0 e

0.0 c
298.6 e

0.0 c
298.6 e

0.0 c
282.2 e

0.0 c
285.8 e

0.0 c
284.7 e
 
0.0 c
303.2 e

0.0 c
287.6 e

0.0 c
 
0.0 c
287.6 e
B3LYP
0.0 c
329.3 e

0.0 c
273.7 e

0.0 c
156.1 d
273.7 e

0.0 c
153.6 d
287.4 e

0.0 c
285.9 e

0.0 c
145.3 d
288.4 e

0.0 c
142.7 d
287.8 e

0.0 c
144.3 d
267.2 e

0.0 c
143.1 d
271.6 e

0.0 c
272.8 e

0.0 c
271.6 e

0.0 c
144.2 d
293.3 e

0.0 c
142.8 d
270.8 e

0.0 c
142.0 d
 
0.0 c
142.8 d
270.8 e
B3LYPultrafine        
0.0 c
                     
B3PW91
0.0 c
168.8 d
343.1 e

0.0 c
156.9 d
292.3 e

0.0 c
156.9 d
292.3 e

0.0 c
154.4 d
301.7 e

0.0 c
146.2 d
299.8 e

0.0 c
145.6 d
302.0 e

0.0 c
143.5 d
302.8 e

0.0 c
144.7 d
285.8 e

0.0 c
143.3 d
289.5 e

0.0 c
288.2 e
 
0.0 c
144.1 d
306.7 e

0.0 c
142.8 d
287.4 e

0.0 c
306.7 e
 
0.0 c
142.8 d
287.4 e
mPW1PW91
0.0 c
171.0 d
349.6 e

0.0 c
154.1 d
301.7 e

0.0 c
159.4 d

0.0 c
311.3 e

0.0 c
143.0 d
308.6 e

0.0 c
142.4 d
310.8 e

0.0 c
140.2 d
311.7 e

0.0 c
141.4 d
294.8 e

0.0 c
144.7 d
298.1 e

0.0 c
296.6 e
 
0.0 c
140.7 d
315.4 e

0.0 c
144.1 d
295.9 e

0.0 c
 
0.0 c
144.1 d
295.9 e
PBEPBE
0.0 c
163.6 d
347.4 e

0.0 c
150.4 d

0.0 c
150.4 d

0.0 c
147.8 d
293.3 e

0.0 c
140.5 d
291.6 e

0.0 c
140.1 d
294.0 e

0.0 c
137.6 d
293.0 e

0.0 c
139.5 d
276.4 e

0.0 c
138.1 d
280.4 e

0.0 c
282.0 e

0.0 c
279.6 e

0.0 c
138.9 d
299.0 e

0.0 c
137.4 d
278.8 e

0.0 c
136.9 d
 
0.0 c
137.4 d
278.8 e
PBEPBEultrafine        
0.0 c
                     
Moller Plesset perturbation MP2
0.0 c
153.3 d
184.5 e

0.0 c
153.5 d

0.0 c
153.5 d

0.0 c
151.7 d

0.0 c

0.0 c
150.7 d

0.0 c

0.0 c
148.7 d

0.0 c
147.1 d

0.0 c
147.6 d
 
0.0 c
147.7 d
295.0 e

0.0 c

NC
 
0.0 c
147.8 d
MP2=FULL
NC

NC

NC

NC

0.0 c
293.2 e

NC

NC

0.0 c
149.2 d

0.0 c
147.4 d
   
NC
     
NC
MP3        
0.0 c
140.3 d
                     
MP4
NC

NC
   
NC
                     
Configuration interaction CID  
NC
   
NC
                     
CISD  
NC
   
NC
                     
Quadratic configuration interaction QCISD
NC

0.0 c
135.8 d
 
NC

NC

0.0 c
135.0 d

0.0 c
133.6 d

NC

0.0 c
131.2 d
   
NC
       
QCISD(T)        
NC
                     
Coupled Cluster CCD
NC

NC
 
NC

NC

NC

NC

NC
     
NC
       
CCSD(T)        
0.0 c
135.1 d
                     

Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF
0.0 c
153.9 d

0.0 c
141.5 d
370.6 e

0.0 c
153.7 d
299.3 e

0.0 c
140.9 d
291.7 e

0.0 c
156.7 d
288.3 e

0.0 c
156.7 d
287.0 e
density functional B1B95
0.0 c
363.3 e

0.0 c
366.7 e
       
B3LYP
0.0 c
140.0 d
351.8 e

0.0 c
134.4 d
353.6 e

0.0 c
142.2 d
303.7 e

0.0 c
137.3 d

0.0 c
143.3 d
285.8 e

0.0 c
143.1 d
285.7 e
Moller Plesset perturbation MP2
0.0 c
135.8 d

0.0 c
138.3 d
348.0 e

0.0 c
130.3 d

0.0 c
135.5 d
295.7 e

0.0 c
141.1 d
229.2 e

0.0 c
140.7 d
228.4 e

Single point energy calculations (select basis sets)
6-311+G(3df,2p) cc-pVDZ cc-pVTZ aug-cc-pVDZ cc-pV(T+d)Z
Moller Plesset perturbation MP2FC// HF/6-31G*  
0.0 c
413.2 d
702.8 e

0.0 c
420.7 d
686.6 e
 
0.0 c
420.7 d
686.6 e
MP2FC// B3LYP/6-31G*  
0.0 c
-108.7 d
301.9 e
     
MP2FC// MP2FC/6-31G*
0.0 c

0.0 c
148.8 d
 
0.0 c
146.1 d
 
MP4// MP2/6-31G*
0.0 c
       
Coupled Cluster CCSD// HF/6-31G*    
0.0 c
 
0.0 c
CCSD(T)// HF/6-31G*    
0.0 c
 
0.0 c
CCSD// MP2FC/6-31G*
0.0 c

0.0 c
     
CCSD(T)// MP2FC/6-31G*
0.0 c

0.0 c
     
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.