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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  
composite G2 10.296
G3 10.378
G3B3 10.371
G3MP2 10.380
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) 6-311+G(3df,2p) TZVP Def2TZVPP 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 9.626 9.637 9.690 9.684 9.677 9.622   9.691 9.681 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 9.748 9.611 9.751     9.761   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   11.066   10.961 11.058   11.051 11.076   11.058
BLYP 8.862 10.120 10.120 10.082 10.062 10.062 10.229 10.200 10.203 10.061   10.249   10.142 10.234   10.250 10.260   10.234
B1B95 9.045 10.261 10.261 10.202 10.189 10.278 10.295 10.379 10.271 10.177   10.306   10.229 10.292   10.300 10.308   10.297
B3LYP 9.081 10.325 10.325 10.272 10.263 10.244 10.376 10.356 10.358 10.241   10.392 10.394 10.309 10.425 10.395 10.389 10.398 10.402 10.380
B3LYPultrafine   10.325     10.247 10.244 10.376 10.356       10.392   10.309 10.381   10.389 10.398    
B3PW91 9.266 10.513 10.513 10.431 10.412 10.408 10.511 10.493 10.492 10.402   10.520   10.453 10.509   10.508 10.522   10.509
mPW1PW91 9.261 10.484 10.501 10.419 10.381 10.375 10.481 10.457 10.472 10.386   10.506   10.422 10.476   10.492 10.506   10.476
M06-2X 9.061 10.298 10.306 10.223 10.217 10.203 10.312 10.325 10.320 10.214   10.332   10.240 10.341   10.313 10.355    
PBEPBE 9.124 10.414 10.414 10.364 10.350 10.346 10.491 10.456 10.456 10.344   10.502 10.504 10.413 10.488   10.499 10.511   10.488
PBEPBEultrafine   10.415     10.350 10.346 10.492 10.456       10.502   10.413 10.487   10.499 10.512    
PBE1PBE 9.195 10.462 10.462 10.391 10.370 10.370 10.470 10.445 10.444 10.358   10.477   10.411 10.465   10.468 10.480    
HSEh1PBE 9.187 10.458 10.458 10.382 10.360 10.354 10.461 10.437 10.436 10.349   10.470   10.401 10.459   10.458 10.473    
TPSSh   10.405 10.405 10.327 10.306 10.299 10.405 10.382   10.292   10.414   10.339 10.404   10.396 10.419    
wB97X-D     10.348   10.215   10.317   10.288     10.318   10.317 10.298     10.362    
B97D3   10.347     10.247   10.358   10.327   10.372       10.360     10.447    
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 Def2TZVPP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pV(T+d)Z
Moller Plesset perturbation MP2 8.459 9.994 9.994 9.934 9.970 10.041 10.124 10.102 10.166 10.146   10.157 10.294 10.128 10.297 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   10.166   10.132 10.297 10.338 10.216 10.323 10.348  
ROMP2 8.411 9.961 9.961 9.901 9.977 10.030 10.114 10.091 10.158 10.141   10.149   10.118 10.280   10.205      
MP3         9.981   10.035         10.150   10.132 10.287          
MP3=FULL         9.987   10.125         10.158   10.136 10.303          
MP4   9.975     9.979       10.161     10.152   10.122 10.296   10.226 10.324    
MP4=FULL   9.975     9.985       10.169         10.126 10.313   10.231 10.343    
B2PLYP 8.791 10.127 10.127 10.071 10.070 10.082 10.193 10.174 10.195 10.115   10.214   10.153 10.248   10.234 10.268    
B2PLYP=FULL 8.790 10.127 10.127 10.071 10.072 10.085 10.195 10.176 10.197 10.118   10.216   10.155 10.253   10.235 10.273    
B2PLYP=FULLultrafine 8.836 10.069 10.069 10.000 9.959 9.952 10.049 10.034 10.033 9.944   10.057   9.999 10.045   10.051 10.056    
Configuration interaction CID   9.962 9.962 9.906 9.945     10.050                        
CISD     9.966 9.910 9.953     10.060                        
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 Def2TZVPP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pV(T+d)Z
Quadratic configuration interaction QCISD   9.977 15.499 9.923 9.971 10.016 10.100 10.083 10.140 10.129   10.131   10.104 10.258   10.201 10.285   10.258
QCISD(T)         9.978     10.095       10.149   10.115 10.291   10.223 10.322   10.291
QCISD(T)=FULL         9.984   10.121             10.120 10.309 10.354 10.227 10.341 10.365  
QCISD(TQ)         9.978   10.114             10.117 10.293 10.335 10.225 10.324 10.345  
QCISD(TQ)=FULL         9.984   10.121             10.121 10.311 10.356 10.230 10.342 10.366  
Coupled Cluster CCD   9.971 9.971 9.918 9.962 10.007 10.089 10.071 10.129 10.116   10.117   10.095 10.243   10.187 10.268   10.243
CCSD         9.970         10.128   10.129   10.103 10.283 10.293 10.199 10.314 10.302  
CCSD=FULL         9.977         10.139   10.138   10.107 10.275 10.314 10.203 10.302 10.322  
CCSD(T)         9.977 10.025   10.094       10.148   10.115 10.291 10.333 10.222 10.321 10.344 10.291
CCSD(T)=FULL         9.984             10.157   10.119 10.309 10.354 10.226 10.340    
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 Def2TZVPP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pV(T+d)Z

Ionization Energies in eV
Methods with effective core potentials (select basis sets)
daug-cc-pVDZ daug-cc-pVTZ daug-cc-pVQZ Sadlej_pVTZ 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.