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Calculated Ionization Energy for I2 (Iodine diatomic)

Experimental Ionization Energy is 9.3074 ± 0.0002 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  

Ionization Energies in eV
Methods with standard basis sets
3-21G 3-21G* Def2TZVPP
hartree fock HF 9.611 8.973 9.057
density functional B3LYP 9.598 9.252 9.431
B3PW91 9.715 9.333  
mPW1PW91 9.749 9.344  
M06-2X   9.575  
PBEPBE 9.377 9.063 9.216
wB97X-D   9.357  
B97D3 9.333    
3-21G 3-21G* Def2TZVPP
Moller Plesset perturbation MP2 9.104 9.156 9.513
MP2=FULL 9.096 9.149  
MP4 9.138    
Configuration interaction CID 9.256 9.144  
CISD 9.240 9.128  
3-21G 3-21G* Def2TZVPP
Quadratic configuration interaction QCISD 9.209 9.156  
Coupled Cluster CCD 9.230 9.183  
3-21G 3-21G* Def2TZVPP

Ionization Energies in eV
Methods with effective core potentials (select basis sets)
daug-cc-pVDZ daug-cc-pVTZ daug-cc-pVQZ Sadlej_pVTZ CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF         9.724   9.724   9.837 9.808
density functional B3LYP         9.873   9.873   9.942 9.966
Moller Plesset perturbation MP2         9.297   9.297   9.337 9.334
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.