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Calculated Ionization Energy for Li2 (Lithium diatomic)

20 09 09 14 00
Experimental Ionization Energy is 5.1127 ± 0.0003 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
composite G4 5.119

Ionization Energies in eV
Methods with standard basis sets
3-21G 3-21G* 6-31G* 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP cc-pVDZ cc-pVTZ aug-cc-pVTZ cc-pV(T+d)Z daug-cc-pVTZ
hartree fock HF     4.191           4.305       4.232 4.231
density functional BLYP     5.150                      
B3LYP                 5.276       5.227  
B3LYPultrafine                       5.228    
mPW1PW91                         5.091  
M06-2X   5.326                        
PBEPBE                         5.157  
HSEh1PBE 5.087                   5.100      
TPSSh     5.173 5.178     5.160       5.170      
wB97X-D   4.997 4.971 4.977   5.008     5.075 4.977 5.005 5.002    
B97D3 5.118   5.077 5.085   5.102   5.095 5.180   5.091 5.085    
3-21G 3-21G* 6-31G* 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP cc-pVDZ cc-pVTZ aug-cc-pVTZ cc-pV(T+d)Z daug-cc-pVTZ
Moller Plesset perturbation MP2     4.699   4.758               4.900  
MP2=FULL                         4.823  
MP3=FULL     4.871 4.883                    
3-21G 3-21G* 6-31G* 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP cc-pVDZ cc-pVTZ aug-cc-pVTZ cc-pV(T+d)Z daug-cc-pVTZ
Quadratic configuration interaction QCISD                         5.089  
3-21G 3-21G* 6-31G* 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP cc-pVDZ cc-pVTZ aug-cc-pVTZ cc-pV(T+d)Z daug-cc-pVTZ

Ionization Energies in eV
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                 4.285
density functional B3LYP                 5.277
PBEPBE                 5.209
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.