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XVII.C.1.

Calculated Ionization Energy for CH3 (Methyl radical)

Experimental Ionization Energy is 9.84 ± 0.01 eV
Please note! These calculated ionizataion energies have the vibrational zero-point energy (zpe) included, but the zpe has NOT been scaled. Click on an entry for more details, including the ionization energy with a scaled zpe.
Original data displayed. Press to display differences.
Differences displayed. Press to display original data.

Ionization Energies in eV
Methods with predefined basis sets
semi-empirical PM6  
composite G3B3 9.905
G4 9.901

Ionization Energies in eV
Methods with standard basis sets
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) TZVP cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
hartree fock HF   9.132     9.010 9.044           9.039   9.044 9.039
density functional LSDA 9.201 10.380 10.380 10.356 10.355 10.495 10.487 10.501 10.374   10.417 10.527 10.511   10.527
B1B95   9.724     9.676 9.778           9.786     9.786
B3LYP   9.834     9.788 9.910     9.798 9.932   9.932   9.946 9.932
B3LYPultrafine                           9.946  
PBEPBE   9.893     9.867 9.999           10.017     10.017
HSEh1PBE         10.733                    
TPSSh         9.813 9.903           9.919      
Moller Plesset perturbation MP2   9.357     9.397 9.553       9.597   9.737   9.770 9.737
MP2=FULL   9.358     9.403 9.560           9.753   9.786  
MP3=FULL         9.382 9.540                  
MP4                       10.609      
B2PLYP                       9.787      
Coupled Cluster CCSD(T)         9.403 9.554           9.750   9.787 9.750
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.