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

Isomers of C8H6

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a C8H6 250259 Pentalene   sketch of Pentalene
b C8H6 4026237 benzocyclobutadiene   sketch of benzocyclobutadiene
c C8H6 6249236 Calicene   sketch of Calicene
d C6H5CCH 536743 phenylacetylene 0.0 sketch of phenylacetylene
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical AM1
157.3 b
0.0 d
PM3 79.1 a
410.2 b
523.4 c
0.0 d
composite G1 61.5 a
96.1 b
208.6 c
0.0 d
G2MP2 56.9 a
91.5 b
203.7 c
0.0 d
G2 58.0 a
92.3 b
204.0 c
0.0 d
G3 61.5 a
95.7 b
207.8 c
0.0 d
G3B3 59.9 a
95.2 b
208.4 c
0.0 d
G3MP2
0.0 d
G4
205.6 c
0.0 d
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 cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z daug-cc-pVTZ
hartree fock HF 49.5 a
89.0 b
265.2 c
0.0 d
125.3 a
160.3 b
304.3 c
0.0 d
125.3 a
160.3 b
304.3 c
0.0 d
115.8 a
146.9 b
287.7 c
0.0 d
86.3 a
112.8 b
223.0 c
0.0 d
86.0 a
112.5 b
221.3 c
0.0 d
87.5 a
115.6 b
220.0 c
0.0 d
89.3 a
118.5 b
225.2 c
0.0 d
90.4 a
119.7 b
223.2 c
0.0 d
86.6 a
113.8 b
216.8 c
0.0 d

0.0 d
96.2 a
125.6 b
226.7 c
0.0 d
82.4 a
111.1 b
218.6 c
0.0 d
90.4 a
119.2 b
218.7 c
0.0 d

215.2 c
0.0 d

216.7 c
0.0 d

0.0 d

NC
density functional LSDA
11.0 b
202.8 c
0.0 d
44.9 a
82.3 b
234.9 c
0.0 d

82.3 b
234.9 c
0.0 d

69.6 b
213.5 c
0.0 d
11.6 a
42.2 b
168.9 c
0.0 d
11.9 a
42.4 b
167.7 c
0.0 d
15.5 a
47.0 b
167.6 c
0.0 d
26.4 a
57.2 b
178.6 c
0.0 d
27.2 a
58.0 b
176.1 c
0.0 d
15.6 a
47.0 b
167.7 c
0.0 d
 
NC
NC
10.5 a
43.0 b
168.5 c
0.0 d
26.4 a
57.8 b
173.9 c
0.0 d

168.8 c
0.0 d

NC

0.0 d
 
BLYP 22.6 a
51.8 b
225.5 c
0.0 d
89.4 a
120.2 b
258.6 c
0.0 d
89.4 a
120.2 b
258.6 c
0.0 d
84.2 a
112.8 b
241.7 c
0.0 d
64.8 a
88.7 b
202.5 c
0.0 d
65.0 a
89.0 b
201.4 c
0.0 d
69.4 a
94.4 b
201.6 c
0.0 d
79.2 a
103.5 b
211.6 c
0.0 d
NC
NC
NC
NC
NC
NC
  NC
NC
NC
65.6 a
91.3 b
203.7 c
0.0 d
81.9 a
106.2 b
208.8 c
0.0 d
   
0.0 d
 
B1B95 11.5 a
41.7 b
216.6 c
0.0 d
83.1 a
115.6 b
256.1 c
0.0 d
83.1 a
115.6 b
256.1 c
0.0 d
77.0 a
106.6 b
238.7 c
0.0 d
43.2 a
66.5 b
176.3 c
0.0 d
77.2 a
100.5 b
210.3 c
0.0 d
55.8 a
80.4 b
184.6 c
0.0 d
62.1 a
87.4 b
193.4 c
0.0 d
62.7 a
88.1 b
191.0 c
0.0 d
53.8 a
78.3 b
182.2 c
0.0 d
  NC
NC
NC
49.6 a
75.1 b
183.5 c
0.0 d
51.3 a
77.6 b
178.0 c
0.0 d

173.9 c
0.0 d

176.7 c
0.0 d

0.0 d
 
B3LYP 23.5 a
54.0 b
232.5 c
0.0 d
92.5 a
123.8 b
266.3 c
0.0 d
92.5 a
123.8 b
266.3 c
0.0 d
85.4 a
114.1 b
248.7 c
0.0 d
64.3 a
87.9 b
203.9 c
0.0 d
64.4 a
88.0 b
202.6 c
0.0 d
67.9 a
92.7 b
202.5 c
0.0 d
76.7 a
101.3 b
212.0 c
0.0 d
77.5 a
102.2 b
209.8 c
0.0 d
70.6 a
94.3 b
203.5 c
0.0 d
  81.5 a
106.4 b
211.4 c
0.0 d
64.1 a
89.5 b
204.1 c
0.0 d
79.0 a
103.5 b
208.4 c
0.0 d

203.5 c
0.0 d
78.4 a
103.4 b
206.8 c
0.0 d

0.0 d
 
B3LYPultrafine         NC
NC
NC
              NC
NC
NC
NC
NC
NC

NC

206.9 c
0.0 d
   
B3PW91 10.8 a
42.1 b
221.1 c
0.0 d
74.7 a
107.8 b
251.7 c
0.0 d
74.7 a
107.8 b
251.7 c
0.0 d
68.3 a
98.2 b
233.4 c
0.0 d
46.8 a
71.0 b
186.2 c
0.0 d
46.9 a
71.1 b
184.8 c
0.0 d
49.3 a
74.7 b
184.4 c
0.0 d
56.0 a
81.6 b
192.6 c
0.0 d
NC
NC
NC
NC
NC
NC
  NC
NC
NC
44.9 a
71.2 b
184.7 c
0.0 d
57.3 a
83.1 b
188.2 c
0.0 d
   
0.0 d
 
mPW1PW91 8.7 a
40.5 b
222.1 c
0.0 d
72.4 a
106.0 b
252.4 c
0.0 d
72.4 a
106.0 b
252.4 c
0.0 d
66.0 a
96.4 b
234.1 c
0.0 d
44.2 a
68.6 b
185.3 c
0.0 d
44.3 a
68.7 b
183.8 c
0.0 d
46.6 a
72.4 b
183.4 c
0.0 d
52.7 a
78.7 b
191.2 c
0.0 d
NC
NC
NC
NC
NC
NC
  NC
NC
NC
42.0 a
68.5 b
183.5 c
0.0 d
54.0 a
80.2 b
186.9 c
0.0 d

NC

NC

0.0 d
 
M06-2X NC
NC
NC
NC
NC
NC
88.8 a
119.9 b
262.2 c
0.0 d
NC
NC
NC
64.6 a
85.6 b
191.3 c
0.0 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
   
PBEPBE 1.7 a
32.4 b
210.1 c
0.0 d
62.9 a
96.5 b
238.9 c
0.0 d
62.9 a
96.4 b
238.9 c
0.0 d
58.8 a
89.4 b
221.4 c
0.0 d
38.4 a
63.4 b
178.3 c
0.0 d
38.6 a
63.6 b
177.0 c
0.0 d
42.0 a
68.2 b
176.9 c
0.0 d
48.9 a
74.9 b
185.3 c
0.0 d
49.6 a
75.7 b
182.9 c
0.0 d
42.1 a
67.7 b
177.2 c
0.0 d
  NC
NC
NC
37.4 a
64.3 b
177.6 c
0.0 d
50.2 a
76.8 b
181.7 c
0.0 d

NC

NC

0.0 d
 
PBEPBEultrafine         38.3 a
63.4 b
178.2 c
0.0 d
              NC
NC
NC
NC
NC
NC

NC

NC
   
PBE1PBE NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
40.9 a
65.2 b
181.8 c
0.0 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
   
HSEh1PBE NC
NC
NC
72.7 a
106.2 b
251.7 c
0.0 d
NC
NC
NC
NC
NC
NC
43.9 a
68.0 b
183.3 c
0.0 d
NC
NC
NC

0.0 d
NC
NC
NC
NC
NC
NC
NC
NC
NC
  NC
NC
NC
NC
NC
NC
54.2 a
79.9 b
185.1 c
0.0 d

NC

NC
   
TPSSh         45.4 a
68.1 b
0.0 d
  48.0 a
71.9 b
0.0 d
    49.0 a
72.3 b
179.6 c
0.0 d
      55.4 a
80.1 b
0.0 d
       
wB97X-D     83.8 a
113.9 b
263.5 c
0.0 d
  53.7 a
73.9 b
197.6 c
0.0 d
  56.4 a
78.0 b
196.0 c
0.0 d
  63.8 a
85.7 b
201.3 c
0.0 d
    67.7 a
90.1 b
203.1 c
0.0 d
56.4 a
78.0 b
196.0 c
0.0 d
63.4 a
86.0 b
197.8 c
0.0 d
  63.3 a
86.2 b
196.8 c
0.0 d
   
B97D3   84.6 a
118.2 b
257.6 c
0.0 d
    60.7 a
86.4 b
194.5 c
0.0 d
  63.8 a
90.6 b
192.8 c
0.0 d
  71.2 a
98.1 b
199.4 c
0.0 d
  73.3 a
100.1 b
195.7 c
0.0 d
76.3 a
103.3 b
202.3 c
0.0 d
  74.1 a
100.3 b
198.5 c
0.0 d
  73.5 a
100.3 b
197.1 c
0.0 d
   
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 83.1 a
127.4 b
308.9 c
0.0 d
128.2 a
169.8 b
320.5 c
0.0 d
128.2 a
169.8 b
320.5 c
0.0 d
119.7 a
301.4 c
0.0 d
71.3 a
101.1 b
225.1 c
0.0 d
69.4 a
99.1 b
222.9 c
0.0 d

0.0 d
72.4 a
102.8 b
225.8 c
0.0 d
71.8 a
101.9 b
222.8 c
0.0 d
65.5 a
97.0 b
218.2 c
0.0 d
    63.7 a
95.5 b
222.1 c
0.0 d
70.1 a
100.8 b
220.7 c
0.0 d

  c

217.8 c
0.0 d

0.0 d
 
MP2=FULL 73.6 a
117.9 b
299.3 c
0.0 d
127.9 a
169.7 b
320.3 c
0.0 d
127.9 a
169.7 b
320.3 c
0.0 d
119.5 a
301.3 c
0.0 d
71.2 a
101.1 b
224.9 c
0.0 d
69.5 a
99.3 b
222.8 c
0.0 d

0.0 d
71.9 a
102.4 b
225.2 c
0.0 d
NC
NC
NC
NC
NC
NC
    63.6 a
95.6 b
221.9 c
0.0 d
71.8 a
101.8 b
219.8 c
0.0 d

NC

NC
   
MP3         NC
NC
NC
                         
MP3=FULL         54.4 a
87.7 b
212.3 c
0.0 d
  55.0 a
0.0 d
                     
MP4  
NC
    NC
NC
     
NC
     
NC
         
MP4=FULL  
NC
    NC
NC
             
NC
         
B2PLYP
NC

NC

NC

NC

214.5 c
0.0 d

NC

NC

NC

NC

NC
   
NC

215.2 c
0.0 d

NC

NC
   
B2PLYP=FULL
NC

NC

NC

NC

NC

NC

NC

NC

NC

NC
   
NC

NC

NC

NC
   
Configuration interaction CID   114.9 a
154.6 b
303.5 c
0.0 d
NC
NC
NC
NC
NC
NC
69.3 a
97.8 b
215.1 c
0.0 d
    NC
NC
NC
                   
CISD   114.6 a
154.7 b
303.3 c
0.0 d
NC
NC
NC
NC
NC
NC
69.2 a
98.0 b
215.4 c
0.0 d
    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 d
101.8 a
148.4 b
303.8 c
0.0 d
101.8 a
148.4 b
303.8 c
0.0 d
94.4 a
136.4 b
286.5 c
0.0 d
58.6 a
92.7 b
218.7 c
0.0 d
56.9 a
90.8 b
216.7 c
0.0 d
NC NC
NC
NC
NC
NC
NC
NC
NC
    51.5 a
87.1 b
214.6 c
0.0 d
         
QCISD(T)         NC
NC
NC
                         
Coupled Cluster CCD   103.7 a
148.5 b
306.9 c
0.0 d
NC
NC
NC
  a
  b
  c
59.6 a
92.3 b
219.3 c
0.0 d
57.6 a
90.2 b
217.2 c
0.0 d
  NC
NC
NC
NC
NC
NC
NC
NC
NC
    NC
NC
NC

NC
       
CCSD         NC
NC
NC
              NC
NC
NC
         
CCSD=FULL         NC
NC
NC
              NC
NC
NC
         
CCSD(T)         NC
NC
NC
             
NC
         
CCSD(T)=FULL        
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 68.6 a
107.6 b
264.4 c
0.0 d
42.3 a
76.0 b
197.2 c
0.0 d
98.6 a
135.4 b
282.5 c
0.0 d
79.4 a
111.0 b
219.7 c
0.0 d
105.7 a
143.0 b
287.8 c
0.0 d
106.0 a
143.3 b
288.2 c
0.0 d
    90.7 a
119.5 b
217.7 c
0.0 d
density functional B1B95
0.0 d

0.0 d
             
B3LYP 44.3 a
79.0 b
227.3 c
0.0 d
27.4 a
58.3 b
183.1 c
0.0 d
68.3 a
101.2 b
243.7 c
0.0 d
58.9 a
87.1 b
202.7 c
0.0 d
73.0 a
105.8 b
246.1 c
0.0 d
73.0 a
105.8 b
245.9 c
0.0 d
    78.0 a
102.7 b
206.8 c
0.0 d
PBEPBE                 49.5 a
76.2 b
180.4 c
0.0 d
Moller Plesset perturbation MP2 80.7 a
274.4 c
0.0 d
35.4 a
70.9 b
204.6 c
0.0 d

0.0 d

0.0 d
112.3 a
151.5 b
296.6 c
0.0 d
112.3 a
151.7 b
296.9 c
0.0 d
    69.5 a
100.3 b
219.3 c
0.0 d
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.