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

Isomers of CH2O2

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a CH2O2 157266 Dioxirane   sketch of Dioxirane
b H2COO 56077920 Dioxymethyl radical   sketch of Dioxymethyl radical
c HCOOH 64186 Formic acid 0.0 sketch of Formic acid
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical AM1
0.0 c
PM3 201.2 a
0.0 c
PM6
0.0 c
MNDOd
0.0 c
composite G1 262.2 a
357.0 b
0.0 c
G2MP2 261.8 a
356.7 b
0.0 c
G2 262.4 a
358.8 b
0.0 c
G3 264.4 a
363.3 b
0.0 c
G3B3 273.3 a
371.4 b
0.0 c
G3MP2 281.3 a
0.0 c
G4 269.5 a
370.6 b
0.0 c
CBS-Q 168.6 a
367.6 b
0.0 c
molecular mechanics MM3
0.0 c

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) 6-311+G(3df,2pd) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ Sadlej_pVTZ daug-cc-pVTZ
hartree fock HF   a
  b
  a
  b
  a
  b
  a
  b

  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b

0.0 c
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b

  b
420.2 a
0.0 c
   
0.0 c
  a
  b
density functional LSDA
  b

  b

  b

  b

  b

  b

  b

  b

  b

  b

  b
 
  b

  b

  b
 
  b

  b
           
BLYP   a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b

  b
 
  b
  a
  b
  a
  b
 
  b

  b
  370.9 a
0.0 c
       
B1B95   a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b

  b

  b
 
  b
  a
  b
  a
  b
 
  b
  a
  b
  362.7 a
0.0 c
       
B3LYP   a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b

  b

0.0 c
  a
  b
  a
  b
  a
  b

  b
  a
  b
  a
  b

  b
384.3 a
0.0 c
   
0.0 c
 
B3LYPultrafine  
  b
      a
  b

  b

  b

  b
   
  b
 
  b

  b
  a
  b
 
  b
  a
  b
           
B3PW91   a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b

  b
 
  b
  a
  b
  a
  b
 
  b
  a
  b
  378.3 a
0.0 c
       
mPW1PW91   a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b

  b
 
  b
  a
  b
  a
  b
 
  b

  b
  376.6 a
0.0 c
       
M06-2X
  b

  b
  a
  b

  b
  a
  b

  b

  b

  b

  b
  a
  b

  b
 
  b

  b
  a
  b
 
  b
  a
  b
           
PBEPBE   a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b

  b

0.0 c

  b
  a
  b
  a
  b
 
  b
  a
  b
  365.9 a
0.0 c
   
0.0 c
 
PBEPBEultrafine  
  b
      a
  b

  b

  b

  b
   
  b
 
  b

  b

  b
 
  b

  b
           
PBE1PBE
  b

  b

  b

  b
  a
  b

  b

  b

  b

  b

  b

  b
 
  b

  b

  b
 
  b

  b
           
HSEh1PBE
  b
  a
  b

  b

  b
  a
  b

  b
  a
  b

  b

  b

  b

  b
 
  b

  b
  a
  b
 
  b

  b
           
TPSSh
  b

  b

  b

  b
  a
  b

  b
  a
  b

  b

  b
  a
  b

  b
 
  b

  b
  a
  b

  b

  b

  b

  b
         
wB97X-D
  b

  b
  a
  b

  b
  a
  b

  b
  a
  b

  b
  a
  b

  b

  b
    a
  b
  a
  b
  a
  b

  b

  b
  a
  b

  b
         
B97D3
  b
  a
  b

  b

  b
  a
  b

  b
  a
  b

  b
  a
  b

  b
  a
  b
    a
  b

  b
  a
  b

  b

  b
  a
  b

  b
         
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) 6-311+G(3df,2pd) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ Sadlej_pVTZ daug-cc-pVTZ
Moller Plesset perturbation MP2   a   a
  b
  a
  b
  a
  b
  a
  b
  a
  b

  b
  a
  b
  a
  b
  a
  b

  b

0.0 c
  a
  b
  a
  b

  b

  b
  a
  b
  a
  b

520.2 b
0.0 c

0.0 c
   
0.0 c
 
MP2=FULL   a   a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b

  b
 
  b
  a
  b
  a
  b

  b

  b
  a
  b

  b
NC    
0.0 c
 
MP3        
  b
 
  b
     
  b
 
  b

  b

  b
                 
MP3=FULL  
  b

  b

  b
  a
  b

  b
  a
  b

  b

  b

  b

  b
 
  b

  b

  b
 
  b

  b
           
MP4     a
  b
      a
  b
     
  b
 
  b
 
  b

  b

  b
 
  b

  b
           
MP4=FULL  
  b
   
  b
     
  b
 
  b
   
  b

  b
 
  b

  b
           
B2PLYP
  b

  b

  b

  b
  a
  b

  b

  b

  b

  b
  a
  b

  b
 
  b

  b
  a
  b
 
  b

  b
           
B2PLYP=FULL
  b

  b

  b

  b

  b

  b

  b

  b

  b

  b

  b
 
  b

  b

  b
 
  b

  b
           
Configuration interaction CID     a
  b
  a
  b
  a
  b
  a
  b
      a
  b
   
  b
                         
CISD     a
  b
  a
  b
  a
  b
  a
  b
      a
  b
   
  b
                         
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) 6-311+G(3df,2pd) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ Sadlej_pVTZ daug-cc-pVTZ
Quadratic configuration interaction QCISD NC   a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b

  b
 
  b
  a
  b
  a
  b
 
  b
  a
  b
 
0.0 c
       
QCISD(T)           a
  b
  NC
  b
NC  
  b
 
  b

  b

  b
 
  b

  b
           
QCISD(T)=FULL        
  b
 
  b
     
  b
   
  b

  b

  b

  b

  b
           
QCISD(TQ)        
0.0 c
 
484.1 b
0.0 c
           
492.9 b
0.0 c

  b
 
484.8 b
0.0 c
             
QCISD(TQ)=FULL        
481.6 b
0.0 c
 
484.8 b
0.0 c
           
493.4 b
0.0 c
   
485.7 b
0.0 c
             
Coupled Cluster CCD NC   a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b

  b
 
  b
  a
  b

  b
 
  b

  b
           
CCSD           a
  b
    a     a   a
  b

  b
 
  b

  b
  a
  b

  b

  b
  a
  b
           
CCSD=FULL           a
  b
          a
  b

  b
 
  b

  b
  a
  b

  b

  b
  a
  b
           
CCSD(T)           a
  b

  b
  a
  b
  a
  b

  b
   
  b

  b

  b
 
  b

  b
 
0.0 c

0.0 c

0.0 c
   
CCSD(T)=FULL        
  b
         
  b
 
  b

  b

  b

  b

  b

  b
 
0.0 c

0.0 c

0.0 c
   
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) 6-311+G(3df,2pd) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ Sadlej_pVTZ 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   a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
      a
  b
density functional B1B95 353.2 a
0.0 c
353.5 a
0.0 c
             
B3LYP   a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
      a
  b
PBEPBE                   a
  b
wB97X-D
  b

  b

  b

  b

  b

  b
     
Moller Plesset perturbation MP2   a
  b
  a
  b
  a
  b
  a
  b
  a
  b
  a
  b
      a
  b

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 c
MP2FC// B3LYP/6-31G*          
0.0 c
MP2FC// MP2FC/6-31G*
0.0 c

0.0 c

0.0 c
   
0.0 c
MP4// HF/6-31G*  
0.0 c
     
0.0 c
MP4// B3LYP/6-31G*          
0.0 c
MP4// MP2/6-31G*
0.0 c
       
0.0 c
Coupled Cluster CCSD// HF/6-31G*
0.0 c

0.0 c

0.0 c

0.0 c

0.0 c

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

0.0 c

0.0 c
   
0.0 c
CCSD(T)// B3LYP/6-31G*          
0.0 c
CCSD(T)//B3LYP/6-31G(2df,p)     288.0 a
0.0 c
    288.0 a
0.0 c
CCSD// MP2FC/6-31G*
0.0 c

0.0 c

0.0 c

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

0.0 c

0.0 c
 
0.0 c
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.