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

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

Isomers of C2H5N

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a CH2CHNH2 593679 aminoethene   sketch of aminoethene
b CH3CHNH 20729413 ethanimine 0.0 sketch of ethanimine
c CH2NCH3 1761677 N-methylmethanimine 20.0 sketch of N-methylmethanimine
d C2H5N 151564 Aziridine 102.0 sketch of Aziridine
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical AM1
0.0 b
-136.4 c
-240.7 d
PM3
0.0 b
-153.4 c
-75.5 d
PM6 -163.3 a
0.0 b
-130.4 c
-86.3 d
MNDOd
104.6 d
composite G1 -179.2 a
0.0 b
31.3 c
296.2 d
G2MP2 -179.3 a
0.0 b
32.1 c
292.6 d
G2 -179.2 a
0.0 b
32.6 c
293.5 d
G3 -181.8 a
0.0 b
33.2 c
294.9 d
G3B3 -168.6 a
0.0 b
-147.3 c
-92.1 d
G3MP2 -179.2 a
0.0 b
36.4 c
298.8 d
G4 -166.1 a
0.0 b
-146.5 c
-92.2 d
CBS-Q -180.4 a
0.0 b
-160.8 c
-106.0 d
molecular mechanics MM3
-0.0 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 cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
hartree fock HF
  d

  d

  d

  d
 
  d
 
  d

  d

  d

NC

  d

  d

  d

  d

  d

NC
density functional LSDA
  d

  d

  d

  d

  d

  d

  d

  d

  d

  d
 
  d

  d
 
  d
 
NC
BLYP
  d

  d

  d

  d

  d

  d

  d

  d

  d

  d
 
  d

  d
 
NC
 
NC
B1B95
  d

  d

  d

  d

  d

  d

  d

  d

  d

  d
 
  d

  d
 
  d
 
NC
B3LYP
  d

  d

  d

  d

  d

  d

  d

  d

  d

  d

NC

  d

  d
 
  d

  d

NC
B3LYPultrafine        
  d
                       
B3PW91
  d

  d

  d

  d

  d

  d

  d

  d

  d

  d
 
  d

  d
 
NC
 
NC
mPW1PW91
  d

  d

  d

  d

  d

  d

  d

  d

  d

  d
 
  d

  d
 
  d
 
NC
PBEPBE
  d

  d

  d

  d

  d

  d

  d

  d

  d

  d

NC

  d

  d
 
  d

  d

NC
Moller Plesset perturbation MP2
  d

  d

  d

  d
 
  d
 
  d

  d

  d
 
  d

  d
 
  d
 
NC
MP2=FULL  
  d
   
  d

  d

  d

  d

  d
   
  d
         
MP3        
  d
                       
MP4        
  d
                       
Configuration interaction CID        
  d
                       
CISD  
  d
   
  d

NC
                     
Quadratic configuration interaction QCISD  
  d
   
  d

  d

  d

  d

  d
   
  d
         
QCISD(T)        
  d
                       
Coupled Cluster CCD        
  d
           
  d
         
CCSD        
  d
                       
CCSD(T)        
  d

NC
                     

Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF
  d

  d

  d

  d

  d

  d
density functional B1B95
-63003.9 d

-63136.3 d
       
B3LYP
  d

  d

  d

  d

  d

  d
Moller Plesset perturbation MP2
  d

  d

  d

  d

  d

  d

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*
NC

NC

NC

NC

NC

NC
MP2FC// B3LYP/6-31G*
NC

NC

  d

NC

NC

NC
MP2FC// MP2FC/6-31G*
NC

NC

NC

NC
 
NC
MP4// HF/6-31G*
NC

NC

NC
   
NC
MP4// B3LYP/6-31G*  
NC

NC
   
NC
MP4// MP2/6-31G*
NC
 
NC
   
NC
Coupled Cluster CCSD// HF/6-31G*
NC

NC

NC

NC
 
NC
CCSD(T)// HF/6-31G*
NC

NC

NC

NC
 
NC
CCSD// B3LYP/6-31G*  
NC

NC
   
NC
CCSD(T)// B3LYP/6-31G*  
NC

  d
   
NC
CCSD(T)//B3LYP/6-31G(2df,p)    
NC
   
NC
CCSD// MP2FC/6-31G*
NC

NC

NC

NC
 
NC
CCSD(T)// MP2FC/6-31G*
NC

NC

NC

NC
 
NC
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.