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

Isomers of C2H3N

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a CHNCH2 157164 2H-Azirine   sketch of 2H-Azirine
b CHNHCH 157175 1H-Azirine   sketch of 1H-Azirine
c H2CCNH 17619226 Ethenimine   sketch of Ethenimine
d HCCNH2 52324046 Ethynamine   sketch of Ethynamine
e H2CNCH 88333022 methyleneaminomethylene   sketch of methyleneaminomethylene
f CH3CN 75058 Acetonitrile 0.0 sketch of Acetonitrile
g CH3NC 593759 methyl isocyanide 99.1 sketch of methyl isocyanide
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical AM1 367.9 a
422.5 b
214.6 c
252.0 d
328.4 e
0.0 f
243.6 g
PM3 324.3 a
370.8 b
212.7 c
233.0 d
178.5 e
0.0 f
131.4 g
PM6 223.5 a
263.1 b
73.0 c
153.7 d
17.1 e
0.0 f
102.3 g
MNDOd
0.0 f
composite G1 200.3 a
338.5 b
111.0 c
178.0 d
229.4 e
0.0 f
100.7 g
G2MP2 196.5 a
332.2 b
109.2 c
176.9 d
225.0 e
0.0 f
96.2 g
G2 197.3 a
333.9 b
109.8 c
177.1 d
226.4 e
0.0 f
98.3 g
G3 201.6 a
337.4 b
108.2 c
174.4 d
228.0 e
0.0 f
101.7 g
G3B3 200.6 a
333.5 b
108.9 c
171.0 d
229.5 e
0.0 f
102.7 g
G3MP2
0.0 f
99.9 g
G4 197.7 a
332.3 b
110.4 c
173.9 d
228.7 e
0.0 f
100.0 g
CBS-Q 200.9 a
335.0 b
107.9 c
175.0 d
224.8 e
0.0 f
98.3 g
molecular mechanics MM3
0.0 f

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 cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
hartree fock HF
0.0 f
99.8 g

0.0 f
84.6 g

0.0 f
84.6 g

0.0 f
84.0 g
 
0.0 f
88.0 g

  g

0.0 f
85.3 g

0.0 f
85.8 g

0.0 f
83.9 g

0.0 f
83.6 g

0.0 f
87.3 g

0.0 f
84.3 g

0.0 f
-0.0 g

0.0 f
85.1 g

0.0 f
83.8 g

0.0 f
84.3 g
density functional LSDA
NC

NC

NC

NC

NC

NC

NC

NC

NC

NC
 
NC

NC
 
NC
 
NC
BLYP
0.0 f
120.2 g

0.0 f
112.1 g

0.0 f
112.1 g

0.0 f
106.9 g
 
0.0 f
103.3 g

0.0 f
95.5 g

0.0 f
102.8 g

0.0 f
103.6 g

0.0 f
97.7 g
 
0.0 f
100.5 g

0.0 f
101.8 g
 
0.0 f
 
0.0 f
101.8 g
B1B95
0.0 f
122.3 g

0.0 f
109.2 g

0.0 f
109.2 g

0.0 f
106.1 g

0.0 f
96.5 g

0.0 f
103.0 g

0.0 f
95.8 g

0.0 f
100.9 g

0.0 f
101.6 g

0.0 f
 
0.0 f
101.1 g

0.0 f
93.5 g
 
0.0 f
 
0.0 f
93.5 g
B3LYP
0.0 f
118.5 g

0.0 f
109.2 g

0.0 f
109.2 g

0.0 f
104.3 g

0.0 f
100.8 g

0.0 f
101.7 g

0.0 f
94.0 g

0.0 f
100.6 g

0.0 f
101.3 g

0.0 f
96.1 g

0.0 f

0.0 f
99.5 g

0.0 f
99.5 g
 
0.0 f
96.1 g

0.0 f
98.7 g

0.0 f
99.5 g
B3LYPultrafine        
0.0 f
100.8 g
                       
B3PW91
0.0 f
125.1 g

0.0 f
111.8 g

0.0 f
111.8 g

0.0 f
107.1 g

0.0 f
103.1 g

0.0 f
104.0 g

0.0 f
97.3 g

0.0 f
102.6 g

0.0 f
103.3 g

0.0 f
99.6 g
 
0.0 f
102.3 g

0.0 f
101.7 g
 
0.0 f
 
0.0 f
101.7 g
mPW1PW91
0.0 f
124.5 g

0.0 f
107.6 g

0.0 f
110.8 g

0.0 f
106.5 g

0.0 f
99.8 g

0.0 f
100.7 g

0.0 f
94.0 g

0.0 f
99.1 g

0.0 f
102.8 g

0.0 f
99.4 g
 
0.0 f
99.0 g

0.0 f
98.3 g
 
0.0 f
 
0.0 f
98.3 g
PBEPBE
0.0 f
130.2 g

0.0 f
116.6 g

0.0 f
116.6 g

0.0 f
112.6 g

0.0 f
107.1 g

0.0 f
108.0 g

0.0 f
100.8 g

0.0 f
106.6 g

0.0 f
107.3 g

0.0 f
103.3 g
 
0.0 f
105.8 g

0.0 f
105.5 g
 
0.0 f

0.0 f
104.5 g

0.0 f
105.5 g
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 cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
Moller Plesset perturbation MP2
0.0 f
167.8 g

0.0 f
131.1 g

0.0 f
131.1 g

0.0 f
134.5 g
 
0.0 f
119.6 g

0.0 f
110.9 g
 
0.0 f
116.7 g
   
0.0 f
117.4 g
   
0.0 f
113.0 g
 
0.0 f
114.5 g
MP2=FULL
NC

0.0 f
130.8 g

NC

NC
 
0.0 f
120.0 g

0.0 f
110.8 g

0.0 f
118.1 g

0.0 f
117.4 g
   
0.0 f
117.4 g
       
NC
MP3        
0.0 f
                       
MP4  
NC
   
0.0 f
107.9 g
                       
Configuration interaction CID  
NC

NC

NC

0.0 f
101.4 g
   
NC
                 
CISD  
  g

NC

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 cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
Quadratic configuration interaction QCISD
NC

0.0 f
112.8 g

NC

NC
 
0.0 f
104.6 g

0.0 f
96.1 g

0.0 f
101.2 g

0.0 f
100.5 g
   
0.0 f
101.3 g
       
NC
QCISD(T)        
0.0 f
106.3 g
 
NC
 
NC
               
Coupled Cluster CCD
NC

NC

NC

NC
 
NC

NC

NC

NC

NC
 
0.0 f
102.3 g

NC
     
NC
CCSD(T)        
0.0 f
106.5 g

0.0 f

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 cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z

Methods with effective core potentials (select basis sets)
daug-cc-pVDZ daug-cc-pVTZ daug-cc-pVQZ Sadlej_pVTZ CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF        
0.0 f
65.9 g

0.0 f
74.5 g

0.0 f
68.7 g

0.0 f
79.7 g

0.0 f
72.8 g

0.0 f
72.9 g
density functional B1B95        
0.0 f
88.5 g

0.0 f
88.5 g
       
B3LYP        
0.0 f
79.6 g

0.0 f
82.5 g

0.0 f
81.6 g

0.0 f
87.9 g

0.0 f
89.5 g

0.0 f
89.7 g
Moller Plesset perturbation MP2        
0.0 f
111.9 g

0.0 f
104.0 g

0.0 f
115.3 g

0.0 f
108.6 g

0.0 f
121.4 g

0.0 f
121.4 g

Single point energy calculations (select basis sets)
6-311+G(3df,2p) cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
Moller Plesset perturbation MP2FC// HF/6-31G*
0.0 f
107.7 g

0.0 f

0.0 f
110.3 g

0.0 f

0.0 f

0.0 f
110.3 g
MP2FC// B3LYP/6-31G*
0.0 f
110.6 g

0.0 f
115.1 g

0.0 f
113.2 g

0.0 f

0.0 f

0.0 f
113.2 g
MP2FC// MP2FC/6-31G*
0.0 f

0.0 f

0.0 f
114.3 g

0.0 f
112.7 g
 
0.0 f
114.3 g
MP4// HF/6-31G*
0.0 f
99.8 g

0.0 f

0.0 f
102.6 g
   
0.0 f
102.6 g
MP4// B3LYP/6-31G*  
0.0 f
103.2 g

0.0 f
104.5 g
   
0.0 f
104.5 g
MP4// MP2/6-31G*
0.0 f
 
0.0 f
105.3 g
   
0.0 f
105.3 g
Coupled Cluster CCSD// HF/6-31G*
0.0 f

0.0 f

0.0 f

0.0 f

0.0 f

0.0 f
CCSD(T)// HF/6-31G*
0.0 f

0.0 f

0.0 f

0.0 f

0.0 f

0.0 f
CCSD// B3LYP/6-31G*
0.0 f
97.8 g

0.0 f

0.0 f
   
0.0 f
CCSD(T)// B3LYP/6-31G*
0.0 f
98.9 g

0.0 f

0.0 f
   
0.0 f
CCSD(T)//B3LYP/6-31G(2df,p)    
0.0 f
101.7 g
   
0.0 f
101.7 g
CCSD// MP2FC/6-31G*
0.0 f

0.0 f

0.0 f

0.0 f
97.9 g
 
0.0 f
CCSD(T)// MP2FC/6-31G*
0.0 f

0.0 f

0.0 f

0.0 f
99.1 g
 
0.0 f
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.