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

Isomers of CH2N

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a H2CN+ 9000286 hydrocyanonium cation   sketch of hydrocyanonium cation
b CNH2+ 9000317 N-protonated hydrogen isocyanide   sketch of N-protonated hydrogen isocyanide
c HCNH+ 54980119 N-protonated HCN   sketch of N-protonated HCN
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical PM3 1239.6 a
1169.9 b
893.5 c
composite G1 NC
NC
NC
G2MP2 NC
NC
NC
G2 NC
NC
NC
G3 NC
NC
NC
G3B3 NC
NC
NC
G4 NC
NC
NC
CBS-Q NC
NC
NC

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 cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ daug-cc-pVTZ
hartree fock HF NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
  NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
ROHF NC NC NC NC NC NC NC NC NC NC     NC NC   NC NC    
density functional LSDA NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
   
NC
NC

NC
NC
 
NC
NC

NC
NC
   
BLYP NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
   
NC
NC

NC
NC
         
B1B95 NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
   
NC
NC

NC
NC
 
NC
NC

NC
   
B3LYP NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
 
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
 
B3LYPultrafine        
NC
NC
                     
NC
NC
   
B3PW91 NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
   
NC
NC

NC
NC
         
mPW1PW91 NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
   
NC
NC

NC
NC
 
NC
NC

NC
NC
   
M06-2X     NC
NC
NC
                               
PBEPBE NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
   
NC
NC

NC
NC
 
NC
NC

NC
NC
   
PBE1PBE        
NC
NC
                           
TPSSh        
NC
 
NC
   
NC
NC
     
NC
         
wB97X-D     NC
NC
NC
 
NC
NC
 
NC
NC
 
NC
   
NC
NC

NC
NC

NC
NC
   
NC
NC
   
B97D3   NC
NC
NC
   
NC
NC
 
NC
NC
 
NC
NC
 
NC
NC

NC
NC
 
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) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ daug-cc-pVTZ
Moller Plesset perturbation MP2 NC
NC
NC

NC
NC

NC
NC
NC
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
 
NC
NC

NC
NC

NC
NC

NC

NC
NC

NC
NC

NC
 
MP2=FULL NC
NC
NC

NC
NC

NC
NC
NC
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
   
NC
NC

NC
NC

NC

NC
NC

NC
NC

NC
NC
 
ROMP2 NC     NC                              
MP3        
NC
NC
                           
MP3=FULL        
NC
 
NC
                       
MP4   NC
NC
NC
   
NC
NC
     
NC
NC
       
NC
NC
         
B2PLYP                          
NC
NC
         
Configuration interaction CID   NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC
   
NC
NC
                     
CISD   NC
NC
NC
NC
NC
NC
NC
NC
NC

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) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ daug-cc-pVTZ
Quadratic configuration interaction QCISD   NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
   
NC
NC

NC
NC
 
NC
NC

NC
   
QCISD(T)        
NC
NC
             
NC
NC

NC
NC
         
Coupled Cluster CCD   NC
NC
NC
NC
NC
NC
NC
NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC

NC
NC
   
NC
NC

NC
NC
 
NC
NC
NC
NC
   
CCSD        
NC
NC
             
NC
NC

NC
NC
         
CCSD(T)        
NC
NC
             
NC
NC

NC
NC

NC

NC
NC

NC

NC
 
CCSD(T)=FULL         NC
NC
NC
             
NC
NC

NC
NC

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) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ daug-cc-pVTZ

Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD cc-pVTZ-PP aug-cc-pVTZ-PP Def2TZVPP
hartree fock HF -41567.3 a
-41674.4 b
-41839.5 c
-41694.6 a
-41783.8 b
-41946.1 c
-41578.7 a
-41686.9 b
-41848.5 c
-41711.9 a
-41800.3 b
-41969.0 c
NC
NC
NC
NC
NC
NC
    NC
NC
NC
density functional B3LYP -42625.3 a
-42711.8 b
-42911.2 c

-42784.6 b
-42970.0 c
-42640.5 a
-42726.7 b
-42920.7 c

-42802.4 b
-42991.1 c
NC
NC
NC
NC
NC
NC
   
NC
NC
PBEPBE                
NC
NC
Moller Plesset perturbation MP2 -41965.7 a
-42080.4 b
-42330.2 c

-42408.5 b
-42639.2 c

-42137.7 b
-42389.3 c

-42466.1 b
-42700.2 c

NC
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 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.