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

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

Isomers of C5H9N

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a C5H9N 694053 1,2,3,6-Tetrahydropyridine   sketch of 1,2,3,6-Tetrahydropyridine
b C5H9N 630182 Propanenitrile, 2,2-dimethyl- 0.0 sketch of Propanenitrile, 2,2-dimethyl-
c C5H9N 18936179 Butanenitrile, 2-methyl- 5.7 sketch of Butanenitrile, 2-methyl-
d C5H9N 110598 Pentanenitrile 14.4 sketch of Pentanenitrile
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical AM1 5.5 a
0.0 b
-13.3 c
-26.2 d
PM3 -0.6 a
0.0 b
2.4 c
-2.4 d
PM6 38.2 a
0.0 b
15.4 c
18.4 d
MNDOd -28.0 a
0.0 b
-19.8 c
-34.9 d
composite G1 130.8 a
0.0 b
20.0 c
27.2 d
G2MP2 126.8 a
0.0 b
20.1 c
26.6 d
G2 128.0 a
0.0 b
20.0 c
26.5 d
G3 128.2 a
0.0 b
20.1 c
26.4 d
G3B3 96.3 a
0.0 b
16.1 c
20.5 d
G3MP2 125.6 a
0.0 b
19.6 c
25.7 d
G4 94.7 a
0.0 b
16.1 c
20.3 d
Group additivity gaw
2.0 c
10.0 d
molecular mechanics MM3 62.4 a
0.0 b
8.5 c
7.9 d

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 64.7 a
0.0 b
5.6 c
3.2 d
114.7 a
0.0 b
13.8 c
15.9 d
114.7 a
0.0 b
13.8 c
15.9 d
83.4 a
0.0 b
7.4 c
5.3 d
  94.7 a
0.0 b
6.5 c
3.8 d
  104.4 a
0.0 b
6.8 c
3.8 d
98.2 a
0.0 b
6.9 c
4.4 d
  a
  c
  d
94.1 a
0.0 b
6.4 c
3.7 d
94.2 a
0.0 b
6.7 c
3.8 d

0.0 b
5.9 c
2.8 d
87.4 a
0.0 b
6.4 c
3.4 d
93.2 a
0.0 b
5.8 c
2.7 d

0.0 b
5.9 c
2.8 d
density functional LSDA 0.5 a
0.0 b
7.3 c
9.2 d
39.2 a
0.0 b
14.4 c
20.7 d
39.2 a
0.0 b
14.4 c
20.7 d
14.0 a
0.0 b
9.7 c
12.2 d
13.9 a
0.0 b
9.7 c
12.2 d
8.7 a
0.0 b
9.5 c
12.1 d
6.2 a
0.0 b
10.3 c
12.6 d
22.3 a
0.0 b
10.2 c
12.3 d
16.1 a
0.0 b
10.4 c
13.2 d
6.7 a
0.0 b
10.8 c
14.1 d
  2.5 a
0.0 b
8.8 c
10.8 d
9.8 a
0.0 b
9.4 c
11.4 d
-2.3 a
0.0 b
9.8 c
12.3 d
  9.8 a
0.0 b
9.4 c
11.4 d
BLYP
0.0 b
5.3 c
4.4 d
105.8 a
0.0 b
9.2 c
9.7 d
  84.6 a
0.0 b
5.6 c
3.7 d
85.1 a
0.0 b
5.4 c
3.6 d
79.8 a
0.0 b
5.3 c
3.4 d
77.9 a
0.0 b
5.7 c
3.4 d
  86.0 a
0.0 b
5.1 c
2.7 d
79.9 a
0.0 b
6.5 c
5.3 d
  72.7 a
0.0 b
4.3 c
1.5 d
83.2 a
0.0 b
4.4 c
1.6 d
69.5 a
0.0 b
5.1 c
2.4 d
  83.2 a
0.0 b
4.4 c
1.6 d
B1B95 51.1 a
0.0 b
5.5 c
4.5 d
87.9 a
0.0 b
13.3 c
17.2 d
87.9 a
0.0 b
13.3 c
17.2 d
62.3 a
0.0 b
7.0 c
6.3 d
64.9 a
0.0 b
6.5 c
5.7 d
60.6 a
0.0 b
6.4 c
5.7 d
58.1 a
0.0 b
6.8 c
6.0 d
71.7 a
0.0 b
6.8 c
5.8 d
65.7 a
0.0 b
7.0 c
6.4 d
59.8 a
0.0 b
6.8 c
6.2 d
  55.9 a
0.0 b
5.7 c
4.1 d
60.0 a
0.0 b
6.4 c
5.1 d
50.2 a
0.0 b
6.4 c
5.2 d
  60.0 a
0.0 b
6.4 c
5.1 d
B3LYP 55.0 a
0.0 b
5.6 c
4.8 d
97.9 a
0.0 b
10.8 c
12.3 d
97.9 a
0.0 b
10.8 c
12.3 d
73.7 a
0.0 b
6.3 c
4.6 d
76.4 a
0.0 b
6.0 c
4.3 d
71.1 a
0.0 b
5.9 c
4.3 d
68.4 a
0.0 b
6.3 c
4.4 d
83.0 a
0.0 b
5.8 c
3.4 d
77.0 a
0.0 b
6.0 c
4.1 d
71.7 a
0.0 b
6.7 c
5.6 d

0.0 b
6.1 c
4.1 d
65.4 a
0.0 b
5.2 c
2.7 d
73.8 a
0.0 b
5.3 c
2.9 d

0.0 b
5.9 c
3.7 d
  73.8 a
0.0 b
5.3 c
2.9 d
B3LYPultrafine         76.4 a
0.0 b
5.9 c
4.3 d
                     
B3PW91
0.0 b
5.4 c
3.8 d
84.3 a
0.0 b
12.1 c
14.2 d
84.3 a
0.0 b
12.1 c
14.2 d
60.0 a
0.0 b
6.4 c
4.6 d
61.4 a
0.0 b
6.0 c
4.1 d
56.0 a
0.0 b
6.0 c
4.2 d
52.9 a
0.0 b
6.4 c
4.4 d
66.6 a
0.0 b
6.3 c
60.5 a
0.0 b
6.5 c
4.7 d
56.0 a
0.0 b
6.4 c
4.9 d
  51.5 a
0.0 b
5.5 c
3.0 d
56.6 a
0.0 b
5.4 c
2.8 d
46.3 a
0.0 b
5.8 c
3.5 d
  56.6 a
0.0 b
5.4 c
2.8 d
mPW1PW91 43.5 a
0.0 b
5.8 c
4.6 d
79.5 a
0.0 b
13.1 c
16.1 d
79.3 a
0.0 b
13.0 c
15.8 d
54.8 a
0.0 b
6.9 c
5.7 d
57.2 a
0.0 b
6.6 c
5.3 d
51.8 a
0.0 b
6.6 c
5.5 d
48.7 a
0.0 b
7.0 c
5.8 d
62.5 a
0.0 b
6.9 c
5.2 d
56.5 a
0.0 b
7.1 c
5.9 d
52.0 a
0.0 b
6.9 c
5.8 d
  47.6 a
0.0 b
6.2 c
4.3 d
52.6 a
0.0 b
6.0 c
4.0 d
42.7 a
0.0 b
6.4 c
4.6 d
  52.6 a
0.0 b
6.0 c
4.0 d
PBEPBE
0.0 b
5.6 c
5.1 d
83.3 a
0.0 b
11.9 c
14.5 d
83.3 a
0.0 b
11.8 c
14.5 d
62.1 a
0.0 b
6.8 c
5.8 d
60.8 a
0.0 b
6.4 c
5.5 d
55.4 a
0.0 b
6.4 c
5.5 d
53.5 a
0.0 b
6.9 c
5.8 d
66.1 a
0.0 b
6.5 c
4.8 d
60.1 a
0.0 b
6.8 c
5.7 d
54.6 a
0.0 b
6.9 c
6.5 d
54.9 a
0.0 b
6.8 c
5.8 d
49.7 a
0.0 b
5.6 c
3.9 d
56.2 a
0.0 b
5.9 c
4.3 d
45.3 a
0.0 b
6.2 c
4.7 d
  56.2 a
0.0 b
5.9 c
4.3 d
PBEPBEultrafine         60.6 a
0.0 b
6.2 c
5.4 d
                     
Moller Plesset perturbation MP2
0.0 b
9.5 c
10.6 d
178.2 a
0.0 b
20.3 c
27.3 d
178.2 a
0.0 b
20.3 c
27.3 d
154.8 a
0.0 b
16.0 c
20.0 d
  112.8 a
0.0 b
15.8 c
20.0 d
  120.8 a
0.0 b
17.6 c
22.0 d
112.6 a
0.0 b
16.7 c
21.5 d
  a
  c
  d
  110.3 a
0.0 b
15.5 c
19.3 d
       
MP2=FULL           a
  c
  d
    120.5 a
0.0 b
18.0 c
22.6 d
112.1 a
0.0 b
17.0 c
22.0 d
             
MP3         87.1 a
0.0 b
12.0 c
12.9 d
                     
Quadratic configuration interaction QCISD  
NC
                           

Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 75.6 a
0.0 b
8.9 c
8.4 d
98.3 a
0.0 b
9.5 c
9.0 d
71.7 a
0.0 b
7.9 c
6.1 d
100.6 a
0.0 b
8.4 c
6.5 d
73.2 a
0.0 b
7.3 c
5.6 d
73.3 a
0.0 b
7.5 c
5.8 d
density functional B1B95 51.8 a
0.0 b
7.9 c
9.0 d
57.1 a
0.0 b
9.0 c
10.7 d
       
B3LYP 68.9 a
0.0 b
8.1 c
8.8 d
75.4 a
0.0 b
9.2 c
10.3 d
61.7 a
0.0 b
7.1 c
6.2 d
75.5 a
0.0 b
7.9 c
7.4 d
62.6 a
0.0 b
6.9 c
6.6 d
62.7 a
0.0 b
6.8 c
6.6 d
Moller Plesset perturbation MP2 158.4 a
0.0 b
18.4 c
25.2 d
123.5 a
0.0 b
20.1 c
27.1 d
150.7 a
0.0 b
20.1 c
27.1 d
119.7 a
0.0 b
22.0 c
29.1 d
158.0 a
0.0 b
17.4 c
24.1 d
158.7 a
0.0 b
17.7 c
24.6 d

Single point energy calculations (select basis sets)
cc-pVDZ cc-pVTZ aug-cc-pVDZ cc-pV(T+d)Z
Moller Plesset perturbation MP2FC// HF/6-31G* 265.6 a
0.0 b
61.8 c
61.1 d
224.8 a
0.0 b
46.5 c
47.1 d
  224.8 a
0.0 b
46.5 c
47.1 d
MP2FC// B3LYP/6-31G* 106.4 a
0.0 b
15.0 c
18.3 d
     
MP2FC// MP2FC/6-31G*     -249.7 a
0.0 b
-333.3 c
-327.4 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 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.