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

Calculated Electron Affininty for C2H (Ethynyl radical)

Experimental Electron Affinity is 2.923 ± 0.037 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  
PM6  
composite G4 2.853
CBS-Q 2.935

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) cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ
hartree fock HF -3.642 0.455 0.455 0.534 2.469 0.679 1.537 1.136 1.140 0.735 1.027 1.299 1.415 1.546 1.522 1.515
density functional LSDA -1.130 2.491 2.491 2.629 2.658 2.664 3.673 3.198 3.213 2.749 3.021 3.398   3.705    
BLYP -1.736 1.705 1.705 1.834 1.827 1.834 2.938 2.385 2.392 1.927 2.195 2.603        
B1B95 -1.601 1.901 1.901 2.019 2.075 2.039 2.924 2.501 2.504 2.109 2.377 2.661   2.958    
B3LYP -1.563 1.951 1.951 2.083 2.067 2.079 3.050 2.599 2.612 2.208   2.812 2.943 3.092 3.078 3.092
B3LYPultrafine         2.068                      
B3PW91 -1.583 1.997 1.997 2.098 2.106 2.133 2.996 2.582 2.588 2.185 2.455 2.740        
mPW1PW91 -1.646 1.978 1.956 2.053 2.102 2.115 2.973 2.554 2.537 2.139 2.433 2.708        
PBEPBE -1.671 1.871 1.871   1.976 1.982 2.981 2.473 2.473 2.056 2.322 2.661        
PBE1PBE         2.053                      
TPSSh             2.857                  
Moller Plesset perturbation MP2 -2.190 1.782 1.782 2.076 2.260 2.290 3.277 2.813 2.838 2.595 2.775 3.224   3.559 3.581  
MP2=FULL   1.785     2.252 2.281 3.267 2.814 2.838   2.773 3.193        
MP3         2.064                      
MP3=FULL         2.055   2.999                  
MP4         2.203                      
B2PLYP                       2.730        
Configuration interaction CID         1.843     2.362                
CISD         1.664                      
Quadratic configuration interaction QCISD   0.980     1.588 1.614 2.554 2.147     2.073 2.549        
QCISD(T)         1.625                      
Coupled Cluster CCD         2.020     2.564     2.530          
CCSD         1.589                      
CCSD(T)                       2.642        

Electron Affinities in eV
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 1.092 1.261 1.156 1.318 1.046 1.051
density functional B3LYP 2.777 2.903   2.693 2.639 2.643
Moller Plesset perturbation MP2 2.852 3.043 2.905 3.014 2.708 2.722
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.