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III.D.6.a. (XVII.D.)

Calculated Electron Affininty for Si2 (Silicon diatomic)

Experimental Electron Affinity is 2.202 ± 0.01 eV
Please note! These calculated electron affinity 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
Electron Affinities in eV
Methods with predefined basis sets
semi-empirical PM3  
composite G2 2.312
G3 2.300
G4 2.251
CBS-Q 2.257
Electron Affinities 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) 6-311+G(3df,2p) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ daug-cc-pVTZ
hartree fock HF -5.953 0.730 0.459 0.720 0.983 0.983 1.186 1.070 1.070 0.850   0.990 0.794 0.307 0.454 0.482 1.061 1.059 1.060
density functional LSDA -3.588 6.552 2.606 2.692 2.609 2.609 2.827 2.780 2.780 2.555     2.471 2.617   2.745      
BLYP -4.257 1.746 1.601 1.777 1.710 1.624 1.911 1.814 1.866 1.579     1.485 1.647          
B1B95 -4.242   1.812 1.891 1.810 1.795 1.971 1.889 1.889 1.811     1.649 1.850   1.886      
B3LYP -4.381 1.940 1.735 1.864 1.751 1.893 2.144 2.026 1.917 1.837   1.974 1.765 1.730 1.873 1.901 1.936 2.096  
B3LYPultrafine         1.751                       1.935    
B3PW91 -4.256 2.095 1.896 2.002 2.013 2.013 2.042 1.996 2.103 1.939     1.731 1.978          
mPW1PW91 -5.444 2.077 1.866 1.980 1.994 1.880 2.013 2.106 2.079 1.758     1.696 1.947          
M06-2X     1.838   1.930           2.072                
PBEPBE -3.967 2.031 1.913 2.034 1.964 1.913 2.186 2.047 2.073 1.843     1.768 1.951          
PBE1PBE         1.986                            
HSEh1PBE   2.045     1.971   2.157             1.928          
TPSSh         1.998   2.164     1.918       1.951          
wB97X-D     1.966   1.980   2.172   2.068     2.025 2.172 1.931     2.101    
B97D3   1.886     1.823   2.075   1.955   2.020 1.907   1.825     2.034   2.033
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ daug-cc-pVTZ
Moller Plesset perturbation MP2 -5.090 1.865 1.705 1.905 1.566 1.694 1.942 1.632 1.797 1.952   1.814 1.722 2.012 2.227 2.134 2.287 2.324  
MP2=FULL   1.867 1.716 1.908 1.769 1.694 1.941 1.794 1.794       1.726 2.034 2.241        
MP3         1.470                            
MP3=FULL         1.468   1.732                        
MP4   1.698     1.686                 1.978          
B2PLYP         1.806                 1.786          
B2PLYP=FULLultrafine         1.706               1.609 1.788     2.050    
Configuration interaction CID   1.318 1.195 1.425 1.370     1.469                      
CISD   1.316 1.232 1.462 1.384                            
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ daug-cc-pVTZ
Quadratic configuration interaction QCISD   1.434 1.452 1.684 1.499   1.760 1.629 1.633       1.519 1.644          
QCISD(T)         1.587               1.584 1.944   2.064      
Coupled Cluster CCD     1.374 1.608 1.421   1.723 1.593         1.486 1.566   1.680      
CCSD         1.514                            
CCSD(T)                         1.563 1.937   2.059      
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ daug-cc-pVTZ
Electron Affinities 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 0.988 0.364 1.057 0.855 1.009 0.639     0.923
density functional B3LYP 1.908 1.794 1.958 1.848 1.921 1.792     1.845
PBEPBE                 1.992
Moller Plesset perturbation MP2 1.537 1.640 1.684 1.707 1.496 1.782     2.087
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.