National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 17bSeptember 2015
NIST Standard Reference Database 101
IIntroduction
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
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IXFeedback
XOlder CCCBDB versions
XIIGeometries
XIII Vibrations
XIVReaction data
XVEntropy data
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XVIIIon data
XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers
XXIOddities

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XVII.C.1. (III.D.6.)

Calculated Ionization Energy for CO2 (Carbon dioxide)

Experimental Ionization Energy is 13.777 ± 0.001 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 PM3  
PM6  
composite G4 13.693
CBS-Q 13.557

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
hartree fock HF 8.326 11.963 11.963 12.131 12.313 12.313 12.386 12.334 12.334 12.226 12.342 12.256 12.309 12.327 12.337 12.329 12.331
density functional LSDA 11.441 14.077 14.077 14.355 14.293 14.293 14.489 14.456 14.456 14.227   14.244 14.443 14.473 14.456 14.478 14.484
SVWN   14.077         14.489       14.505            
BLYP 10.429 12.972 12.972 13.279 13.219 13.219 13.473 13.378 13.378 13.146   13.171 13.393        
B1B95 10.787 13.469 13.469 13.722 13.538 13.667 13.822 13.752 13.752 13.581   13.610 13.608 13.638 13.648 13.644 13.648
B3LYP 10.637 13.301 13.301 13.583 13.551 13.551 13.752 13.675 13.675 13.473 13.749 13.495 13.679 13.716 13.716 13.724 13.728
B3LYPultrafine         13.551                        
B3PW91 10.742 13.435 13.435 13.641 13.608 13.608 13.752 13.699 13.699 13.519   13.556 13.677        
mPW1PW91 10.681 13.372 13.406 13.603 13.547 13.547 13.694 13.630 13.660 13.487   13.495 13.612        
M06-2X     13.760   13.760                        
PBEPBE 10.642 13.209 13.209 13.452 13.389 13.389 13.593 13.511 13.511 13.308   13.348 13.515 13.556     13.571
PBE1PBE         13.545                        
HSEh1PBE   13.356     13.536   13.686           13.613        
TPSSh         13.396   13.547     13.307     13.478        
wB97X-D     13.476   13.659       13.723       13.669     13.697  
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
Moller Plesset perturbation MP2 10.261 13.514 13.514 14.031 14.073 14.073 14.238 14.070 14.070 14.175 14.149 13.962 14.346   14.309 14.469  
MP2=FULL 10.262 13.516 13.516 14.033 14.075 14.075 14.241 14.077 14.077 14.177   13.966 14.352     14.472  
MP3         13.444                        
MP3=FULL         13.448   13.574                    
MP4   13.268     13.644       13.688       13.955        
B2PLYP         13.566                        
Configuration interaction CID   12.707 12.707 13.097 13.281     13.279                  
CISD     12.575 12.908 13.203     13.223                  
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
Quadratic configuration interaction QCISD   12.414 12.414 12.758 13.146 13.146 13.284 13.182 13.182 13.317   13.065 13.445        
QCISD(T)         13.210             13.131 13.531   13.445 13.646  
Coupled Cluster CCD   12.795 12.795 13.243 13.453 13.454 13.590 13.450 13.450 13.586   13.352 13.709   13.653 13.811  
CCSD         13.171                        
CCSD=FULL                                 13.685
CCSD(T)                       13.151 13.555   13.466 13.669  
CCSD(T)=FULL         13.237                       13.776
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

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 12.056 12.249 11.998 12.288 12.054 12.052
density functional B3LYP 13.596 13.511 13.522 13.546 13.659 13.642
Moller Plesset perturbation MP2 14.109 14.099 14.109 14.132 14.152 14.153
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.