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

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

Isomers of C6H12O2

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a C6H12O2 142621 Hexanoic acid   sketch of Hexanoic acid
b C6H12O2 598981 Methyl pivalate   sketch of Methyl pivalate
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
composite CBS-Q 0.0 a
20.0 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) cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ
hartree fock HF 0.0 a
-6.5 b
0.0 a
-5.1 b
0.0 a
-5.1 b
0.0 a
29.0 b
  0.0 a
35.7 b
0.0 a
38.5 b
0.0 a
25.0 b
0.0 a
36.8 b
0.0 a
33.7 b
0.0 a
37.2 b
0.0 a
38.1 b
0.0 a
39.8 b
0.0 a
43.8 b
0.0 a
39.1 b
ROHF   0.0 a
-5.1 b
0.0 a
-5.1 b
0.0 a
29.0 b
0.0 a
24.1 b
0.0 a
35.7 b
0.0 a
38.5 b
0.0 a
25.0 b
  0.0 a
33.7 b
0.0 a
37.2 b
0.0 a
38.1 b
  0.0 a
43.8 b
0.0 a
39.1 b
density functional LSDA     0.0 a
-14.8 b
0.0 a
13.5 b
0.0 a
9.4 b
0.0 a
19.7 b
0.0 a
27.4 b
0.0 a
14.6 b
0.0 a
25.3 b
  0.0 a
24.4 b
0.0 a
28.3 b
0.0 a
30.0 b
0.0 a
32.3 b
 
BLYP 0.0 a
-25.0 b
0.0 a
-10.7 b
0.0 a
-10.7 b
0.0 a
15.7 b
0.0 a
13.5 b
0.0 a
23.6 b
0.0 a
33.5 b
0.0 a
20.3 b
0.0 a
30.4 b
0.0 a
20.8 b
0.0 a
29.0 b
0.0 a
33.4 b
     
B1B95 0.0 a
-13.3 b
0.0 a
-9.3 b
0.0 a
-9.3 b
0.0 a
20.6 b
0.0 a
18.4 b
0.0 a
28.9 b
    0.0 a
32.5 b
0.0 a
26.8 b
    0.0 a
36.4 b
0.0 a
41.2 b
0.0 a
36.5 b
B3LYP 0.0 a
-19.9 b
0.0 a
-8.2 b
0.0 a
-8.2 b
0.0 a
20.2 b
0.0 a
16.7 b
    0.0 a
21.8 b
0.0 a
32.5 b
0.0 a
24.6 b
    0.0 a
37.0 b
0.0 a
41.3 b
0.0 a
37.2 b
B3PW91 0.0 a
-11.7 b
0.0 a
-0.1 b
0.0 a
-0.1 b
0.0 a
26.5 b
0.0 a
23.0 b
0.0 a
33.6 b
0.0 a
39.7 b
0.0 a
26.3 b
0.0 a
37.4 b
0.0 a
31.6 b
0.0 a
37.1 b
0.0 a
40.1 b
     
mPW1PW91 0.0 a
-11.8 b
0.0 a
-1.9 b
0.0 a
-1.8 b
0.0 a
25.9 b
0.0 a
22.1 b
0.0 a
32.8 b
0.0 a
39.0 b
0.0 a
25.1 b
0.0 a
36.4 b
0.0 a
31.0 b
0.0 a
36.1 b
0.0 a
39.4 b
     
PBEPBE 0.0 a
-18.6 b
  0.0 a
-6.4 b
0.0 a
20.8 b
      0.0 a
23.1 b
0.0 a
33.7 b
      0.0 a
38.9 b
   
Moller Plesset perturbation MP2 0.0 a
-18.1 b
0.0 a
-15.4 b
    0.0 a
10.2 b
0.0 a
18.8 b
0.0 a
20.8 b
  0.0 a
25.8 b
  0.0 a
25.7 b
       
MP2=FULL 0.0 a
-18.0 b
0.0 a
-15.8 b
0.0 a
-15.8 b
0.0 a
15.1 b
0.0 a
8.9 b
    0.0 a
10.7 b
  0.0 a
7.8 b
0.0 a
24.8 b
       
MP3         0.0 a
19.7 b
                   
Configuration interaction CID   0.0 a
-8.9 b
0.0 a
-8.9 b
0.0 a
23.0 b
0.0 a
18.7 b
    0.0 a
19.7 b
             
CISD   0.0 a
-9.8 b
0.0 a
-9.8 b
0.0 a
21.9 b
0.0 a
18.0 b
    0.0 a
19.2 b
             
Coupled Cluster CCSD         0.0 a
16.0 b
                   

Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 0.0 a
26.7 b
0.0 a
19.7 b
0.0 a
32.2 b
0.0 a
26.1 b
0.0 a
32.0 b
0.0 a
32.0 b
density functional B3LYP 0.0 a
18.9 b
0.0 a
15.2 b
       
Moller Plesset perturbation MP2 0.0 a
10.0 b
0.0 a
5.5 b
0.0 a
8.8 b
0.0 a
6.0 b
0.0 a
13.1 b
0.0 a
12.8 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 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.