return to home page

XVII.C.1.

Calculated Ionization Energy for Li2 (Lithium diatomic)

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 G2 5.208
G3 5.204
G3B3 5.209
G4 5.119
CBS-Q 5.111

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 cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pV(T+d)Z
hartree fock HF 3.601 4.217 4.217 4.208 4.191 4.191 4.208 4.247 4.247 4.170 4.305 4.211 4.232 4.230 4.218 4.231 4.230 4.232
density functional SVWN   5.567     5.596   5.602                      
B1B95 4.538 4.995 4.995 5.032 5.031 5.031 5.038 5.024 5.024 5.009   5.024            
B3LYP 4.776 5.237 5.237 5.251 5.236 5.236 5.245 5.241 5.241 5.222 5.276 5.237 5.227 5.229 5.236 5.228 5.228 5.227
B3LYPultrafine         5.236                          
mPW1PW91 4.582 5.085 5.085 5.104 5.090 5.090 5.096 5.104 5.104 5.077   5.091 5.091         5.091
M06-2X         5.334                          
PBEPBE 4.684 5.153 5.153 5.181 5.169 5.169 5.175 5.169 5.169 5.157   5.164 5.157         5.157
PBE1PBE         5.103                          
HSEh1PBE         5.102                          
TPSSh             5.178                      
Moller Plesset perturbation MP2 4.034 4.639 4.639 4.671 4.709 4.709 4.710 4.758 4.758 4.753 4.584 4.799 4.900 5.183 4.750 4.925 4.832 4.900
MP2=FULL 4.041 4.648 4.648 4.637 4.702 4.702 4.716 4.770 4.770 4.774   4.738 4.823 4.885     4.887 4.823
MP3=FULL         4.871   4.883                      
MP4   4.883     4.938       4.996       5.022          
Quadratic configuration interaction QCISD   4.947 4.947 4.937 4.998 4.998 5.009 5.060 5.060 5.031   5.043 5.089         5.089
Coupled Cluster CCD   4.941 4.941 4.929 4.996 4.996 5.006 5.057 5.057 5.028   5.040 5.084   5.049 5.085    
CCSD(T)=FULL         5.004                 5.158     5.155  

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 4.116 4.086 4.297 4.257 4.238 4.253
density functional B3LYP 4.960 4.933 5.115 5.084 5.252 5.240
Moller Plesset perturbation MP2 4.575 4.602 4.773 4.768 4.650 4.728
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.