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

Isomers of C2H4O2

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a CHOCH2OH 141468 hydroxy acetaldehyde   sketch of hydroxy acetaldehyde
b C2H4O2 61233190 1,3-dioxetane   sketch of 1,3-dioxetane
c CH3COOH 64197 Acetic acid 0.0 sketch of Acetic acid
d CH3OCHO 107313 methyl formate 79.9 sketch of methyl formate
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical AM1 -209.2 a
-381.2 d
PM6 115.3 a
200.5 b
0.0 c
72.5 d
MNDOd
0.0 c
65.2 d
composite G1 115.1 a
233.4 b
0.0 c
69.4 d
G2MP2 111.6 a
229.2 b
0.0 c
68.7 d
G2 112.3 a
230.6 b
0.0 c
69.2 d
G3 113.5 a
235.4 b
0.0 c
71.8 d
G3B3 111.2 a
230.8 b
0.0 c
70.7 d
G3MP2 112.4 a
235.3 b
0.0 c
72.1 d
G4 111.6 a
227.2 b
0.0 c
69.9 d
CBS-Q 112.3 a
232.7 b
0.0 c
70.7 d
molecular mechanics DREIDING
0.0 c
MM3
0.0 c
-54.9 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 98.6 a
0.0 c
28.0 d
129.6 a
0.0 c
54.5 d
129.6 a
0.0 c
54.5 d
116.5 a
0.0 c
75.5 d
  123.5 a
0.0 c
70.2 d
  123.5 a
0.0 c
57.8 d
120.9 a
0.0 c
70.9 d
121.8 a
0.0 c
68.0 d
116.6 a
0.0 c
67.7 d
121.5 a
0.0 c
71.3 d
118.4 a
0.0 c
69.0 d
112.6 a
0.0 c
74.6 d
116.1 a
0.0 c
68.8 d
118.4 a
0.0 c
69.0 d
density functional LSDA 117.9 a
0.0 c
7.0 d
131.2 a
0.0 c
52.5 d
131.2 a
0.0 c
52.5 d
124.9 a
0.0 c
69.6 d
121.6 a
0.0 c
57.0 d
120.8 a
0.0 c
67.8 d
118.0 a
0.0 c
74.2 d
126.1 a
0.0 c
62.1 d
122.9 a
0.0 c
75.1 d
117.4 a
0.0 c
66.3 d
  118.8 a
0.0 c
71.5 d
117.9 a
0.0 c
74.5 d
111.4 a
0.0 c
77.1 d
  117.9 a
0.0 c
74.5 d
BLYP 118.8 a
0.0 c
5.9 d
124.6 a
0.0 c
37.0 d
124.6 a
0.0 c
37.0 d
116.7 a
0.0 c
52.6 d
  115.3 a
0.0 c
54.6 d
111.8 a
0.0 c
61.4 d
  a
  d
117.7 a
0.0 c
61.6 d
112.8 a
0.0 c
53.7 d
  114.0 a
0.0 c
58.4 d
113.6 a
0.0 c

0.0 c
65.6 d
  113.6 a
0.0 c
B1B95 118.7 a
0.0 c
18.7 d
140.1 a
0.0 c
50.8 d
140.1 a
0.0 c
50.8 d
132.8 a
0.0 c
66.9 d
121.2 a
0.0 c
55.2 d
130.9 a
0.0 c
65.9 d
127.9 a
0.0 c
70.3 d
134.6 a
0.0 c
57.5 d
131.9 a
0.0 c
70.5 d

0.0 c
64.7 d
  128.5 a
0.0 c
69.1 d
116.9 a
0.0 c
69.9 d

0.0 c
74.6 d
  116.9 a
0.0 c
69.9 d
B3LYP 113.5 a
0.0 c
12.8 d
126.6 a
0.0 c
45.8 d
126.6 a
0.0 c
45.8 d
117.4 a
0.0 c
61.7 d
118.4 a
0.0 c
50.4 d
118.1 a
0.0 c
61.3 d
114.1 a
0.0 c
66.7 d
121.6 a
0.0 c
54.7 d
119.2 a
0.0 c
66.9 d
115.6 a
0.0 c
60.0 d

0.0 c
66.0 d
116.5 a
0.0 c
115.4 a
0.0 c
66.1 d
109.0 a
0.0 c
88.8 d
112.3 a
0.0 c
66.9 d
115.4 a
0.0 c
66.1 d
B3LYPultrafine         118.4 a
0.0 c
50.4 d
                     
B3PW91 118.3 a
0.0 c
19.1 d
131.2 a
0.0 c
54.2 d
131.2 a
0.0 c
54.2 d
121.0 a
0.0 c
68.5 d
122.1 a
0.0 c
56.7 d
121.6 a
0.0 c
67.9 d
117.4 a
0.0 c
71.9 d
123.8 a
0.0 c
59.3 d
121.3 a
0.0 c
72.2 d
118.8 a
0.0 c
66.6 d
  119.5 a
0.0 c
70.3 d
117.5 a
0.0 c
71.4 d

0.0 c
75.0 d
  117.5 a
0.0 c
71.4 d
mPW1PW91 116.4 a
0.0 c
20.6 d
126.9 a
0.0 c
55.3 d
131.3 a
0.0 c
55.4 d
121.0 a
0.0 c
70.2 d
118.6 a
0.0 c
57.7 d
118.2 a
0.0 c
69.2 d
114.2 a
0.0 c
73.2 d
120.2 a
0.0 c
60.0 d
121.5 a
0.0 c
73.3 d
119.2 a
0.0 c
67.8 d
  115.8 a
0.0 c
71.4 d
114.0 a
0.0 c
72.5 d

0.0 c
76.2 d
  114.0 a
0.0 c
72.5 d
PBEPBE 123.1 a
0.0 c
13.0 d
129.0 a
0.0 c
47.6 d
129.0 a
0.0 c
47.6 d
121.2 a
0.0 c
62.1 d
119.9 a
0.0 c
52.6 d
119.4 a
0.0 c
63.4 d
115.9 a
0.0 c
69.3 d
123.1 a
0.0 c
56.8 d
120.5 a
0.0 c
69.3 d
116.3 a
0.0 c
62.4 d

0.0 c
69.1 d
117.5 a
0.0 c
82.9 d
116.3 a
0.0 c
69.0 d

0.0 c
72.6 d
113.2 a
0.0 c
70.0 d
116.3 a
0.0 c
69.0 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) cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
Moller Plesset perturbation MP2 103.7 a
0.0 c
17.6 d
129.2 a
0.0 c
49.1 d
  a
  d
120.0 a
0.0 c
69.4 d
  124.4 a
0.0 c
67.8 d
    123.5 a
0.0 c
75.3 d
    123.8 a
0.0 c
73.4 d
  113.4 a
0.0 c
75.7 d
  119.7 a
0.0 c
73.1 d
MP2=FULL NC 129.2 a
0.0 c
49.1 d
NC NC   125.0 a
0.0 c
67.9 d
119.8 a
0.0 c
71.2 d
130.7 a
0.0 c
62.8 d
123.9 a
0.0 c
75.9 d
    124.1 a
0.0 c
73.4 d
      NC
MP3        
0.0 c
63.1 d
                     
MP4   NC     122.1 a
0.0 c
55.7 d
                     
Configuration interaction CID   NC NC NC 123.1 a
0.0 c
85.9 d
    NC                
CISD   NC NC NC 123.5 a
0.0 c
85.0 d
    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) cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
Quadratic configuration interaction QCISD NC 120.2 a
0.0 c
71.5 d
NC NC   117.8 a
0.0 c
64.9 d
113.0 a
0.0 c
67.8 d
123.5 a
0.0 c
59.9 d
116.7 a
0.0 c
71.0 d
    NC        
QCISD(T)         NC   NC   NC              
Coupled Cluster CCD NC NC NC NC   NC NC NC NC NC   NC        
CCSD             NC   NC              
CCSD(T)         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) cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z

Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 102.9 a
0.0 c
71.6 d
116.4 a
0.0 c
55.0 d
102.3 a
0.0 c
74.2 d
116.0 a
0.0 c
59.1 d
106.1 a
0.0 c
77.8 d
106.4 a
0.0 c
78.0 d
density functional B1B95 112.1 a
0.0 c
66.2 d
118.9 a
0.0 c
56.3 d
       
B3LYP 107.3 a
0.0 c
60.4 d
113.5 a
0.0 c
51.0 d
104.7 a
0.0 c
61.4 d
111.9 a
0.0 c
54.4 d
110.0 a
0.0 c
66.4 d
110.3 a
0.0 c
66.2 d
Moller Plesset perturbation MP2 107.9 a
0.0 c
65.0 d
121.4 a
0.0 c
58.6 d
106.2 a
0.0 c
65.4 d
120.1 a
0.0 c
61.3 d
110.0 a
0.0 c
68.6 d
110.2 a
0.0 c
68.7 d

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* 119.2 a
0.0 c
72.6 d

0.0 c
76.2 d
120.5 a
0.0 c
74.3 d

0.0 c
75.7 d
120.5 a
0.0 c
74.3 d
MP2FC// B3LYP/6-31G*
0.0 c
123.5 a
0.0 c
74.1 d
118.8 a
0.0 c
73.1 d

0.0 c
76.2 d
118.8 a
0.0 c
73.1 d
MP2FC// MP2FC/6-31G*  
0.0 c
74.2 d
119.1 a
0.0 c
73.2 d
112.7 a
0.0 c
76.2 d
119.1 a
0.0 c
73.2 d
MP4// HF/6-31G* 115.7 a
0.0 c
68.7 d

0.0 c
72.8 d
116.8 a
0.0 c
70.8 d
  116.8 a
0.0 c
70.8 d
MP4// B3LYP/6-31G*   119.0 a
0.0 c
69.0 d
115.4 a
0.0 c
69.2 d
  115.4 a
0.0 c
69.2 d
MP4// MP2/6-31G*     115.4 a
0.0 c
69.1 d
  115.4 a
0.0 c
69.1 d
Coupled Cluster CCSD// HF/6-31G*  
0.0 c
72.8 d

0.0 c
72.1 d
 
0.0 c
72.1 d
CCSD(T)// HF/6-31G*  
0.0 c
71.7 d

0.0 c
71.3 d
 
0.0 c
71.3 d
CCSD// B3LYP/6-31G*
0.0 c

0.0 c
70.5 d
     
CCSD(T)// B3LYP/6-31G*
0.0 c

0.0 c
69.3 d
     
CCSD(T)//B3LYP/6-31G(2df,p)     113.8 a
0.0 c
69.4 d
  113.8 a
0.0 c
69.4 d
CCSD// MP2FC/6-31G*  
0.0 c
70.6 d

0.0 c
70.8 d
106.2 a
0.0 c
73.0 d

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

0.0 c
69.7 d
106.9 a
0.0 c
71.8 d

0.0 c
69.7 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.