return to home page

XVII.C.1.

Calculated Ionization Energy for CH2 (Methylene)

Experimental Ionization Energy is 10.396 ± 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 AM1  
PM3  
PM6  
composite G3 10.378
G3B3 10.371
G4 10.348
CBS-Q 10.320

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 8.578 9.813 9.813 9.715 9.652 9.637 9.690 9.684 9.677 9.622 9.691 9.652 9.674 9.680 9.671 9.678 9.681 9.674
ROHF   9.722 9.722 9.750 9.579 9.565 9.620 9.611 9.751     9.583 9.606 9.763 9.746 9.760 9.764 9.606
density functional LSDA 9.505 10.950 10.950 10.898 10.894 10.896 11.039 11.031 11.034 10.895   10.961 11.058   11.051 11.076   11.058
SVWN   10.950     10.894   11.039                      
BLYP 8.862 10.120 10.120 10.082 10.062 10.062 10.229 10.200 10.203 10.061   10.142 10.234         10.234
B1B95 9.060 10.265 10.265 10.203 10.192 10.184 10.300 10.383 10.275 10.183   10.237 10.297   10.307 10.313   10.297
B3LYP 9.081 10.325 10.325 10.272 10.247 10.244 10.376 10.356 10.358 10.241 10.392 10.309 10.380 10.395 10.389 10.398 10.402 10.380
B3LYPultrafine         10.247                     10.398    
B3PW91 9.266 10.513 10.513 10.431 10.412 10.408 10.511 10.493 10.492 10.402   10.453 10.509         10.509
mPW1PW91 9.261 10.484 10.501 10.419 10.381 10.375 10.481 10.457 10.472 10.386   10.422 10.476         10.476
M06-2X         10.217                          
PBEPBE 9.124 10.414 10.414 10.364 10.350 10.346 10.491 10.456 10.456 10.344   10.413 10.488         10.488
PBE1PBE         10.370                          
HSEh1PBE         10.360                          
TPSSh         10.306   10.405           10.404          
Moller Plesset perturbation MP2 8.459 9.994 9.994 9.934 9.992 10.041 10.124 10.102 10.166 10.146 10.157 10.128 10.281 10.319 10.212 10.306 10.329 10.281
MP2=FULL 8.457 9.993 9.993 9.933 9.998 10.049 10.131 10.110 10.173 10.156   10.132 10.297 10.338   10.323 10.348  
ROMP2 8.479 9.723 9.723 9.623 9.573 9.560 9.616 9.606 9.602 9.549   9.580 9.602   9.600      
MP3         9.981                          
MP3=FULL         9.987   10.125                      
MP4   9.975     9.978       10.161       10.296          
B2PLYP         10.070               10.248          
Configuration interaction CID   9.962 9.962 9.906 9.945     10.050                    
CISD     9.966 9.910 9.953     10.060                    
Quadratic configuration interaction QCISD   9.977   9.923 9.971 10.016 10.100 10.083 10.140 10.129   10.104 10.258         10.258
QCISD(T)         9.978             10.115 10.291   10.223 10.323   10.291
Coupled Cluster CCD   9.971 9.971 9.918 9.962 10.007 10.089 10.071 10.129 10.116   10.095 10.243   10.187 10.268   10.243
CCSD         9.970                          
CCSD(T)         9.313             10.115 10.291   10.222 10.321   10.291
CCSD(T)=FULL         12.522                          

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 9.686 9.613 9.737 9.648 9.782 9.780
density functional B3LYP 10.243 10.207 10.288 10.253 10.404 10.391
Moller Plesset perturbation MP2 9.902 9.964 9.965 10.015 10.021 10.019
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.