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XVII.C.1.

Calculated Ionization Energy for C2H4 (Ethylene)

Experimental Ionization Energy is 10.5138 ± 0.0006 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 10.533
G4 10.429
CBS-Q 10.537

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 aug-cc-pVDZ aug-cc-pVTZ
hartree fock HF 7.383 8.896 8.896 8.739 8.647 8.643 8.747 8.726 8.733 8.611 8.770 8.702 8.738 8.720 8.746
density functional SVWN   11.068     10.935   11.096                
BLYP 8.873 10.008 10.008 9.929 9.893 9.900 10.078 10.096 10.106 9.906   10.006 10.134    
B1B95 9.102 10.205 10.205 9.682 10.061 10.077 10.197 10.205 10.210 10.080   10.152 10.205 10.188  
B3LYP 9.014 10.206 10.206 10.106 10.064 10.069 10.219 10.238 10.248 10.072 10.293 10.163 10.272 10.241 10.285
B3LYPultrafine         10.064                   10.294
B3PW91 9.084 10.271 10.271 10.143 10.099 10.104 10.216 10.236 10.244 10.099   10.174 10.254    
mPW1PW91 9.030 10.213 10.237 10.105 10.033 10.037 10.154 10.165 10.196 10.054   10.110 10.186    
M06-2X         10.049                    
PBEPBE 9.049 10.195 10.195 10.099 10.061 10.063 10.211 10.223 10.228 10.064   10.153 10.250    
PBE1PBE         10.040                    
HSEh1PBE         11.332                    
TPSSh             10.089                
Moller Plesset perturbation MP2 8.243 9.933 9.933 9.840 9.944 10.025 10.167 10.140 10.246 10.205 10.248 10.165 10.436 10.306 10.494
MP2=FULL 8.245 9.935 9.935 9.842 9.958 10.039 10.179 10.154 10.259 10.226   10.175 10.466 10.316 10.523
MP3         9.803   10.046                
MP3=FULL         9.814   10.022                
MP4   9.973     9.952       10.236       10.402    
Configuration interaction CID   9.742 9.742 9.620 9.625     9.769              
CISD     9.761 9.645 9.643     9.785              
Quadratic configuration interaction QCISD   9.934 9.934 9.833 9.863 9.936 10.052 10.017 10.109 10.061   10.042 10.250    
QCISD(T)         9.957             10.148 10.393    
Coupled Cluster CCD   9.913 9.913 9.805 9.821 9.897 10.011 9.978 10.072 10.029   10.008 10.218    
CCSD(T)         9.956             10.147 10.392 10.277 10.438
CCSD(T)=FULL         9.966               10.420 10.284  

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 8.620 8.520 8.759 8.682 8.819 8.823
density functional B3LYP 9.935 9.876 10.088 10.051 10.181 10.175
Moller Plesset perturbation MP2 9.687 9.813 9.898 10.017 9.938 9.944
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.