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

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

Isomers of C7H16

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a C7H16 142825 heptane   sketch of heptane
b C7H16 589344 3-methylhexane   sketch of 3-methylhexane
c C7H16 591764 2-methylhexane   sketch of 2-methylhexane
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
composite G1 0.0 a
-4.6 b
-7.4 c
G2MP2 0.0 a
-4.3 b
-7.2 c
G2 0.0 a
-4.4 b
-7.2 c
G3 0.0 a
-3.9 b
-6.7 c
G3B3 0.0 a
-4.6 b
G3MP2 0.0 a
-1.9 b
-6.9 c

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
hartree fock HF 0.0 a
8.3 b
3.2 c
0.0 a
3.1 b
-1.9 c
0.0 a
-1.9 c
0.0 a
7.5 b
1.9 c
  0.0 a
8.8 b
2.9 c
0.0 a
8.8 b
2.7 c
0.0 a
9.0 b
2.8 c
0.0 a
8.6 b
2.6 c
0.0 a
9.1 b
3.1 c
0.0 a
2.9 c
0.0 a
9.0 b
2.8 c
0.0 a
9.1 b
3.0 c
0.0 a
9.6 b
3.3 c
0.0 a
9.1 b
2.9 c

NC
NC
0.0 a
3.3 c
density functional LSDA 0.0 a
-3.3 b
-4.1 c
0.0 a
-11.8 b
-11.3 c
0.0 a
-11.3 c
0.0 a
-7.2 b
-7.7 c
0.0 a
-6.3 b
-7.2 c
0.0 a
-6.8 b
-7.5 c
0.0 a
-6.1 b
-7.3 c
0.0 a
-6.7 b
-7.8 c
0.0 a
-7.6 b
-8.4 c
0.0 a
-7.4 b
-8.1 c
    0.0 a
-6.6 b
-7.6 c
0.0 a
-6.6 b
-7.7 c
0.0 a
-8.6 c
  0.0 a
-7.7 c
SVWN   0.0 a
-11.8 b
    0.0 a
-6.3 b
  0.0 a
-6.1 b
                   
BLYP
NC
NC
0.0 a
2.3 b
-1.8 c
0.0 a
-1.8 c
0.0 a
5.0 b
0.5 c
0.0 a
5.7 b
1.0 c
0.0 a
5.5 b
0.9 c
0.0 a
6.2 b
1.1 c
0.0 a
6.7 b
1.5 c
0.0 a
6.1 b
1.0 c
0.0 a
5.0 b
0.3 c
    0.0 a
5.9 b
0.9 c
0.0 a
6.6 b
     
B1B95 0.0 a
4.9 b
-7.9 c
0.0 a
-3.8 b
-5.8 c
0.0 a
-5.8 c
0.0 a
4.2 b
1.1 c
0.0 a
2.5 b
-0.9 c
0.0 a
1.2 b
-2.1 c
0.0 a
2.0 b
-1.5 c
0.0 a
2.4 b
-0.8 c
0.0 a
2.1 b
-1.1 c
0.0 a
0.6 b
    0.0 a
1.0 b
-2.7 c
0.0 a
2.7 b
-1.0 c
    0.0 a
-1.0 c
B3LYP 0.0 a
4.7 b
1.0 c
0.0 a
1.0 b
-2.8 c
0.0 a
-2.8 c
0.0 a
4.4 b
0.1 c
0.0 a
5.3 b
0.7 c
0.0 a
5.0 b
0.5 c
0.0 a
5.5 b
0.6 c
0.0 a
5.7 b
0.8 c
0.0 a
5.1 b
0.3 c
0.0 a
4.7 b
0.2 c
  0.0 a
5.5 b
0.5 c
0.0 a
5.3 b
0.5 c
0.0 a
5.8 b
0.8 c
0.0 a
-0.0 c
  0.0 a
0.8 c
B3LYPultrafine        
NC
NC
                       
B3PW91
NC
NC
0.0 a
0.1 b
-3.6 c
0.0 a
-3.6 c
0.0 a
4.2 b
0.0 c
0.0 a
5.1 b
0.6 c
0.0 a
4.7 b
0.4 c
0.0 a
4.9 b
0.3 c
0.0 a
4.9 b
0.4 c
0.0 a
4.3 b
-0.1 c
0.0 a
4.7 b
0.3 c
    0.0 a
5.1 b
0.5 c
0.0 a
5.4 b
0.6 c
    0.0 a
0.6 c
mPW1PW91 0.0 a
5.0 b
1.1 c
0.0 a
-8.1 b
-11.3 c
0.0 a
-11.2 c
0.0 a
-3.5 b
-7.3 c
0.0 a
-2.6 b
-6.6 c
0.0 a
-2.9 b
-6.9 c
0.0 a
-2.6 b
-6.9 c
0.0 a
-2.6 b
-6.8 c
0.0 a
3.2 b
-0.9 c
0.0 a
3.7 b
-0.3 c
    0.0 a
-2.7 b
-7.0 c
0.0 a
-2.1 b
-6.5 c
    0.0 a
-6.5 c
M06-2X         0.0 a
-3.7 b
-5.8 c
                       
PBEPBE
NC
NC
0.0 a
-2.2 b
-5.0 c
0.0 a
-5.0 c
0.0 a
1.9 b
-1.6 c
0.0 a
2.7 b
-1.1 c
0.0 a
2.3 b
-1.3 c
0.0 a
2.8 b
-1.3 c
0.0 a
2.9 b
-1.1 c
0.0 a
2.2 b
-1.7 c
0.0 a
2.1 b
-1.5 c
    0.0 a
2.6 b
-1.3 c
0.0 a
3.1 b
-1.1 c
    0.0 a
-1.1 c
PBE1PBE         0.0 a
2.9 b
-0.9 c
                       
HSEh1PBE         0.0 a
2.7 b
                       
TPSSh             0.0 a
3.8 b
-0.4 c
                   
Moller Plesset perturbation MP2   0.0 a
-5.2 b
-7.8 c
0.0 a
-7.8 c
0.0 a
-5.1 c
0.0 a
-2.0 b
-5.6 c
0.0 a
-5.7 c
  0.0 a
-7.1 c
0.0 a
-7.3 c
0.0 a
-7.5 c
  0.0 a
-5.1 b
-7.9 c
0.0 a
-6.4 c
  0.0 a
-8.7 c
   
MP2=FULL   0.0 a
-5.3 b
-8.0 c
0.0 a
-8.0 c
0.0 a
-5.3 c
0.0 a
-2.3 b
-5.9 c
0.0 a
-6.0 c
0.0 a
-7.0 c
0.0 a
-7.4 c
0.0 a
-7.5 c
0.0 a
-10.0 c
    0.0 a
-6.6 c
       
MP3=FULL         0.0 a
0.5 b
-3.5 c
  0.0 a
-0.8 b
-4.4 c
                   
B2PLYP         0.0 a
2.5 b
                0.0 a
1.9 b
-2.2 c
     
Quadratic configuration interaction QCISD   0.0 a
-6.3 c
0.0 a
-6.3 c
0.0 a
-3.6 c
0.0 a
-3.1 c
0.0 a
-3.1 c
                     
Coupled Cluster CCD   0.0 a
-6.2 c
    0.0 a
-2.9 c
                       

Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 0.0 a
6.4 b
0.7 c
0.0 a
7.0 b
0.9 c
0.0 a
7.8 b
2.0 c
0.0 a
8.6 b
2.3 c
0.0 a
7.4 b
1.8 c
0.0 a
7.2 b
1.8 c
density functional B1B95 0.0 a
-3.2 c
0.0 a
-3.2 c
       
B3LYP 0.0 a
2.7 b
-1.5 c
0.0 a
2.7 b
-1.8 c
0.0 a
4.4 b
-0.2 c
0.0 a
4.8 b
-0.2 c
0.0 a
3.2 b
-0.8 c
0.0 a
3.2 b
-0.7 c
Moller Plesset perturbation MP2 0.0 a
-5.9 b
-8.1 c
0.0 a
-5.3 b
-8.3 c
0.0 a
-6.4 b
-8.7 c
0.0 a
-5.9 b
-9.1 c
0.0 a
-6.3 b
-8.4 c
0.0 a
-6.5 b
-8.6 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.