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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   sketch of dioxymethyl
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 585.3 a
0.0 c
PM6 451.8 a
0.0 c
MNDOd
0.0 c
composite G1 375.1 a
0.0 c
G2MP2 374.5 a
0.0 c
G2 375.2 a
0.0 c
G3 377.4 a
0.0 c
G3B3 378.1 a
0.0 c
G3MP2 377.5 a
0.0 c
G4 374.1 a
0.0 c
CBS-Q 374.9 a
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) cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ
hartree fock HF 148.3 a
0.0 c
385.1 a
0.0 c
385.1 a
0.0 c
422.3 a
0.0 c
  419.8 a
0.0 c
  414.9 a
0.0 c
427.4 a
0.0 c
417.3 a
0.0 c
425.2 a
0.0 c

0.0 c
423.4 a
0.0 c
420.2 a
0.0 c
423.1 a
0.0 c
424.7 a
0.0 c
420.6 a
0.0 c
420.2 a
0.0 c
   
density functional LSDA 173.6 a
0.0 c
362.5 a
0.0 c
362.5 a
0.0 c
380.8 a
0.0 c
363.9 a
0.0 c
373.7 a
0.0 c
380.7 a
0.0 c
381.6 a
0.0 c
393.8 a
0.0 c
371.9 a
0.0 c
    380.8 a
0.0 c
382.9 a
0.0 c
  380.9 a
0.0 c
  382.9 a
0.0 c
   
BLYP 161.6 a
0.0 c
330.9 a
0.0 c
330.9 a
0.0 c
349.4 a
0.0 c
  358.6 a
0.0 c
367.3 a
0.0 c
366.2 a
0.0 c
377.0 a
0.0 c
359.7 a
0.0 c
    365.2 a
0.0 c
370.9 a
0.0 c
 
0.0 c
  370.9 a
0.0 c
   
B1B95 153.8 a
0.0 c
343.4 a
0.0 c
343.4 a
0.0 c
368.1 a
0.0 c
347.6 a
0.0 c
368.5 a
0.0 c
375.9 a
0.0 c
371.4 a
0.0 c
383.5 a
0.0 c

0.0 c
    374.2 a
0.0 c
362.7 a
0.0 c
 
0.0 c
  362.7 a
0.0 c
   
B3LYP 155.2 a
0.0 c
345.0 a
0.0 c
345.1 a
0.0 c
368.0 a
0.0 c
363.7 a
0.0 c
373.8 a
0.0 c
382.5 a
0.0 c
379.3 a
0.0 c
390.8 a
0.0 c
374.2 a
0.0 c

0.0 c

0.0 c
379.5 a
0.0 c
384.3 a
0.0 c
  383.2 a
0.0 c
384.1 a
0.0 c
384.3 a
0.0 c
   
B3LYPultrafine         363.7 a
0.0 c
                             
B3PW91 156.5 a
0.0 c
347.1 a
0.0 c
347.1 a
0.0 c
370.1 a
0.0 c
361.6 a
0.0 c
372.1 a
0.0 c
379.1 a
0.0 c
375.0 a
0.0 c
387.2 a
0.0 c
370.7 a
0.0 c
    376.8 a
0.0 c
378.3 a
0.0 c
 
0.0 c
  378.3 a
0.0 c
   
mPW1PW91 154.5 a
0.0 c
345.8 a
0.0 c
349.4 a
0.0 c
373.1 a
0.0 c
360.2 a
0.0 c
370.9 a
0.0 c
378.3 a
0.0 c
373.1 a
0.0 c
388.6 a
0.0 c
372.3 a
0.0 c
    375.5 a
0.0 c
376.6 a
0.0 c
 
0.0 c
  376.6 a
0.0 c
   
PBEPBE 165.8 a
0.0 c
335.0 a
0.0 c
334.9 a
0.0 c
354.8 a
0.0 c
348.0 a
0.0 c
358.0 a
0.0 c
365.6 a
0.0 c
363.0 a
0.0 c
374.8 a
0.0 c
356.8 a
0.0 c

0.0 c

0.0 c
364.3 a
0.0 c
366.0 a
0.0 c
 
0.0 c
365.2 a
0.0 c
366.0 a
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) cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ
Moller Plesset perturbation MP2 169.6 a
0.0 c
345.3 a
0.0 c
345.3 a
0.0 c
368.7 a
0.0 c
  381.7 a
0.0 c
    399.7 a
0.0 c
   
0.0 c
394.0 a
0.0 c
    390.2 a
0.0 c
 
0.0 c
   
MP2=FULL NC 345.4 a
0.0 c
NC NC   382.5 a
0.0 c
388.6 a
0.0 c
386.7 a
0.0 c
400.3 a
0.0 c
      394.4 a
0.0 c
        NC    
MP3        
0.0 c
                             
MP4   NC     365.4 a
0.0 c
                             
Configuration interaction CID   NC NC NC 382.2 a
0.0 c
    NC                        
CISD     a NC NC 381.3 a
0.0 c
    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) 6-311+G(3df,2pd) cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ
Quadratic configuration interaction QCISD NC 332.7 a
0.0 c
NC NC   378.3 a
0.0 c
384.4 a
0.0 c
380.3 a
0.0 c
392.3 a
0.0 c
      387.1 a
0.0 c
             
QCISD(T)         362.5 a
0.0 c
  NC   NC                      
Coupled Cluster CCD NC NC NC NC   NC NC NC NC NC     386.1 a
0.0 c
             
CCSD             NC   NC                      
CCSD(T)         361.6 a
0.0 c

0.0 c
NC   NC        
0.0 c
 
0.0 c

0.0 c

0.0 c
   
CCSD(T)=FULL        
0.0 c
             
0.0 c

0.0 c
 
0.0 c

0.0 c

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

Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 399.9 a
0.0 c
394.0 a
0.0 c
398.6 a
0.0 c
401.5 a
0.0 c
410.3 a
0.0 c
410.2 a
0.0 c
density functional B1B95 353.3 a
0.0 c
353.6 a
0.0 c
       
B3LYP 343.7 a
0.0 c
351.2 a
0.0 c
343.8 a
0.0 c
357.6 a
0.0 c
359.2 a
0.0 c
359.4 a
0.0 c
Moller Plesset perturbation MP2 349.7 a
0.0 c
361.0 a
0.0 c
350.2 a
0.0 c
367.0 a
0.0 c
363.0 a
0.0 c
362.7 a
0.0 c

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

0.0 c

0.0 c

0.0 c

0.0 c

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

0.0 c

0.0 c

0.0 c

0.0 c

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

0.0 c

0.0 c

0.0 c
 
0.0 c
MP4// HF/6-31G*
0.0 c

0.0 c

0.0 c
   
0.0 c
MP4// B3LYP/6-31G*  
0.0 c

0.0 c
   
0.0 c
MP4// MP2/6-31G*
0.0 c
 
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

0.0 c

0.0 c

0.0 c

0.0 c

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

0.0 c

0.0 c
   
0.0 c
CCSD(T)//B3LYP/6-31G(2df,p)     376.0 a
0.0 c
    376.0 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
 
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.