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XVII.C.1.

Calculated Ionization Energy for H2CO (Formaldehyde)

Experimental Ionization Energy is 10.885 ± 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 AM1  
PM3  
PM6  
composite G4 10.818
CBS-Q 10.900

Ionization Energies in eV
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) TZVP cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
hartree fock HF 6.937 9.242 9.242 9.358 9.340 9.324 9.423 9.358 9.345 9.284 9.400 9.281 9.359 9.392 9.394 9.359
density functional LSDA 9.107 11.042 11.041 11.231 11.152 11.134 11.320 11.235 11.210 11.084   11.067 11.246 11.276   11.246
SVWN   11.041     11.153   11.321                  
BLYP 8.441 10.284 10.284 10.483 10.410 10.392 10.621 10.501 10.482 10.338   10.339 10.537     10.537
B1B95 8.644 10.464 10.464 10.622 10.486 10.532 10.686 10.592 10.572 10.481   10.471 10.539 10.577 10.586 10.539
B3LYP 8.649 10.540 10.540 10.722 10.649 10.632 10.821 10.719 10.700 10.577 10.797 10.574 10.744 10.781 10.799 10.744
B3LYPultrafine         10.649                   10.799  
B3PW91 8.695 10.593 10.593 10.729 10.655 10.637 10.784 10.703 10.683 10.579   10.576 10.707     10.707
mPW1PW91 8.646 10.533 10.558 10.689 10.591 10.572 10.721 10.637 10.640 10.537   10.516 10.642     10.642
M06-2X         10.758                      
PBEPBE 8.549 10.419 10.419 10.579 10.501 10.481 10.673 10.568 10.545 10.426   10.429 10.591     10.591
PBE1PBE         10.575                      
HSEh1PBE         10.573                      
TPSSh             10.650                  
Moller Plesset perturbation MP2 7.933 10.430 10.430 10.711 10.790 10.848 11.028 10.816 10.890 10.956 10.987 10.779 11.147 11.100 11.260 11.147
MP2=FULL 7.934 10.432 10.432 10.713 10.793 10.851 11.031 10.822 10.896 10.959   10.782 11.152      
MP3         10.489   10.770                  
MP3=FULL         10.491   10.703                  
MP4   10.296     10.564       10.710              
B2PLYP         10.576                      
Configuration interaction CID   10.110 10.110 10.324 10.339     10.354                
CISD     9.987 10.191 10.242     10.267                
Quadratic configuration interaction QCISD   10.006 10.006 10.227 10.297 10.375 10.529 10.324 10.415 10.475   10.318 10.635     10.635
QCISD(T)         10.339             10.364        
Coupled Cluster CCD   10.242 10.242 10.478 10.508 10.572 10.721 10.527 10.607 10.675   10.515 10.826 10.787 10.918  
CCSD(T)         10.346             10.370 10.723 10.664 10.825 10.723
CCSD(T)=FULL         10.348                      

Ionization Energies in eV
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 9.355 9.340 9.359 9.362 9.383 9.383
density functional B3LYP 10.740 10.649 10.765 10.695 10.808 10.800
Moller Plesset perturbation MP2 10.746 10.826 10.822 10.877 10.825 10.829
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.