return to home page Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
You are here: Comparisons > Energy > Similar molecules > Isomers OR FAQ Help > List > Similar molecules > Isomers

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

Isomers of CHO

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a HCO+ 2597446 Formyl cation   sketch of Formyl cation
b COH+ 71080927 Carbon Monoxide, protonated   sketch of Carbon Monoxide, protonated
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical AM1 827.4 a
PM3 740.1 a
PM6 802.6 a
composite G1 NC
NC
G2MP2 NC
NC
G2 NC
NC
G3 NC
NC
G3B3 NC
NC
G3MP2 NC
G4 NC
NC
CBS-Q 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
hartree fock HF
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
BLYP
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
B3LYP
NC

NC

NC

NC

NC

NC

NC

NC

NC

NC
 
NC

NC

NC

NC

NC

NC

NC
B3LYPultrafine  
NC
   
NC

NC

NC

NC
     
NC

NC

NC
 
NC

NC
 
B3PW91
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
 
M06-2X
NC

NC

NC

NC

NC

NC

NC

NC

NC

NC
 
NC

NC

NC
 
NC

NC
 
PBEPBE
NC

NC

NC

NC

NC

NC

NC

NC

NC

NC
 
NC

NC

NC
NC
NC

NC
NC
PBEPBEultrafine  
NC
   
NC

NC

NC

NC
     
NC

NC

NC
 
NC

NC
 
PBE1PBE
NC

NC

NC

NC

NC

NC

NC

NC

NC

NC
 
NC

NC

NC
 
NC

NC
 
HSEh1PBE
NC

NC

NC

NC

NC

NC

NC

NC

NC

NC
 
NC

NC

NC
 
NC

NC
 
TPSSh
NC

NC

NC

NC

NC

NC

NC

NC

NC

NC
 
NC

NC

NC

NC

NC

NC

NC
wB97X-D
NC

NC

NC

NC

NC

NC

NC

NC

NC

NC
 
NC

NC

NC

NC

NC

NC

NC
B97D3                    
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
Moller Plesset perturbation MP2
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
MP3        
NC
 
NC
       
NC

NC

NC
       
MP3=FULL  
NC

NC

NC
NC
NC

NC
NC
NC

NC

NC

NC
 
NC

NC

NC
 
NC

NC
 
MP4  
NC
   
NC
     
NC
     
NC
NC
NC
   
NC
 
MP4=FULL  
NC
   
NC
     
NC
     
NC

NC
   
NC
 
B2PLYP
NC

NC

NC

NC

NC

NC

NC

NC

NC

NC
 
NC

NC

NC
 
NC

NC
 
B2PLYP=FULL
NC

NC

NC

NC

NC

NC

NC

NC

NC

NC
 
NC

NC

NC
 
NC

NC
 
Configuration interaction CID  
NC

NC

NC

NC
   
NC
                   
CISD  
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
Quadratic configuration interaction QCISD  
NC

NC

NC

NC
   
NC

NC

NC
   
NC

NC
       
QCISD(T)        
NC
   
NC
       
NC

NC
   
NC
 
QCISD(T)=FULL        
NC
 
NC
         
NC

NC

NC
 
NC

NC
QCISD(TQ)        
NC
 
NC
         
NC

NC

NC
 
NC
 
QCISD(TQ)=FULL        
NC
 
NC
         
NC

NC

NC
 
NC
 
Coupled Cluster CCD  
NC

NC

NC

NC

NC

NC

NC

NC

NC
   
NC

NC
   
NC
 
CCSD        
NC
       
NC
   
NC

NC

NC
 
NC

NC
CCSD=FULL        
NC
       
NC
   
NC

NC

NC
 
NC

NC
CCSD(T)        
NC

NC
 
NC
       
NC

NC

NC
 
NC

NC
CCSD(T)=FULL        
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

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
-55910.7 b

-56056.6 b

-55924.3 b

-56069.8 b

NC

NC
     
density functional B3LYP
-57052.3 b

-57153.9 b

-57066.8 b

-57167.0 b

NC

NC
   
NC
PBEPBE                
NC
wB97X-D
-57048.2 b

-57156.4 b

-57062.8 b

-57170.2 b

NC

NC
     
Moller Plesset perturbation MP2
-56355.2 b

-56735.6 b

-56419.9 b

-56790.2 b

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.