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XVII.C.1.

Calculated Ionization Energy for Na2 (Sodium diatomic)

Experimental Ionization Energy is 4.892 ± 0.003 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 CBS-Q 4.792
Ionization Energies in eV
Methods with standard basis sets
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 3.955 3.905 3.988 3.964 3.964 3.966 3.981 3.981 3.960 4.008 3.950 3.958 3.958   3.959 3.958 3.958
density functional LSDA 5.411 5.901 5.610 5.602 5.602 5.603 5.607 5.607 5.616   5.582 5.583   5.588     5.583
SVWN 5.508     5.602   5.603                      
BLYP 5.099 5.379 5.093 5.083 5.083 5.084 5.086 5.086 5.086                
B1B95 4.672 4.912 4.870 4.827 4.858           4.838 4.778         4.778
B3LYP 5.141 5.377 5.150 5.138 5.138 5.138 5.135 5.135 5.134 5.150 5.123 5.116 5.124   5.117 5.126 5.116
B3LYPultrafine       5.138                          
B3PW91 4.859 4.973 4.901 4.885 4.885 4.885 4.884 4.884 4.875                
mPW1PW91 4.876 4.896 4.904 4.861 4.861 4.862 4.860 4.885 4.874     4.859         4.859
M06-2X       5.254                          
PBEPBE 5.063 5.279 5.076 5.062 5.062 5.062 5.063 5.063 5.051   5.043 5.040         5.040
HSEh1PBE       4.948                          
Moller Plesset perturbation MP2FC 4.339 4.346 3.973 4.430 4.430 4.370 4.435 4.435 4.424 4.374 4.420 4.489 4.494 4.432 4.482   4.489
MP2FU 4.346     4.458 4.458 4.460 4.505 4.505                  
MP4       4.616               4.651          
B2PLYP       4.909   4.885                      
Configuration interaction CID       4.655     4.668                    
CISD       4.660                          
Quadratic configuration interaction QCISD 4.589     4.660 4.660 4.661 4.672 4.672     4.668 4.698         4.698
QCISD(T)       4.660                          
Coupled Cluster CCD       4.655     4.668       4.664            
CCSD       4.660                          
CCSD(T)                     4.668 4.698   4.673     4.698
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     4.011 3.984 3.853 4.043
density functional B3LYP     4.802   4.686 5.178
Moller Plesset perturbation MP2FC           4.437
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.