National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 19April 2018
NIST Standard Reference Database 101
IIntroduction
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
VIInput and output files
VIITutorials and Units
VIIILinks to other sites
IXFeedback
XOlder CCCBDB versions
XIIGeometries
XIII Vibrations
XIVReaction data
XVEntropy data
XVIBibliographic data
XVIIIon data
XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers
XXIOddities

NIST policy on privacy, security, and accessibility.

Please rate our products
© 2013 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved.

The National Institute of Standards and Technology (NIST) is an agency of the U.S. Department of Commerce.

Please send questions, comments, corrections, additions and suggestions to cccbdb@nist.gov.

return to home page

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

Calculated Ionization Energy for HOCO (Hydrocarboxyl radical)

Experimental Ionization Energy is 8.2 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 G2 7.971
G3 8.006
G3B3 8.015
G4 8.064
CBS-Q 8.012

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
hartree fock HF 5.987 7.818 7.818 8.242 7.716 7.693 7.831 7.640 7.630 7.468   7.715 7.626 7.605 7.610 7.623 7.742 7.654 7.638
ROHF   7.721 7.721 8.143 7.607 7.584 7.542 7.528 7.518         7.491 7.493 7.507 7.631 7.539 7.522
density functional LSDA 6.402 8.080 8.080 8.545 8.317 8.302 8.632 8.381 8.385 8.157       8.279 8.425   8.589    
BLYP 5.989 7.660 7.660 8.086 7.841 7.822 8.159 7.907 7.899 7.660       7.800 7.941        
B1B95 6.174 7.816 7.816 8.185 7.883 7.712 8.087 7.880 7.875 7.682       7.818 7.881   8.024 7.946  
B3LYP 6.302 7.949 7.949 8.369 8.082 8.062 8.339 8.108 8.101 7.884   8.227 8.156 8.026 8.123 8.161 8.285 8.200 8.189
B3LYPultrafine         8.082                         8.200  
B3PW91 6.303 8.000 8.000 8.367 8.081 8.061 8.280 8.085 8.078 7.883       8.021 8.078        
mPW1PW91 6.317 8.019 8.019 8.383 8.086 8.064 8.286 8.080 8.073 7.883       8.023 8.074        
M06-2X     8.013   7.979                            
PBEPBE 5.986 7.760 7.760 8.136 7.895 7.876 8.169 7.942 7.935 7.717     8.006 7.856 7.967        
PBE1PBE         8.034                            
HSEh1PBE   7.951     8.031   8.238               8.036        
TPSSh         8.033   8.237     7.835         8.044        
wB97X-D     7.934   8.024   8.217   7.995     8.074   8.217 7.966     8.024  
B97D3   7.859     7.925   8.160   7.944   8.016       7.950     8.031  
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
Moller Plesset perturbation MP2   7.026 7.026 7.494 7.465 7.477 7.737 7.421 7.464 7.409   7.602 7.699 7.397 7.669   7.768 7.796  
MP2=FULL   7.024 7.024 7.491 7.447 7.459 7.717 7.410 7.453 7.341       7.390 7.626     7.737  
ROMP2 10.679 16.837 16.837 17.465 20.451 20.546 20.888 21.402 21.575 22.865       20.702 24.021   21.591    
MP3         7.724                            
MP3=FULL         7.706   7.934                        
MP4   7.082     7.513       7.524                    
B2PLYP         7.832                   7.924        
Configuration interaction CID   7.450 7.450 7.934 7.695     7.627                      
CISD   7.449 7.449 7.937 7.691     7.626                      
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
Quadratic configuration interaction QCISD   7.422 7.422 7.939 7.724 7.731 7.981 7.681 7.715 7.659       7.651 7.901        
QCISD(T)         7.660                 7.599 7.877   7.983 8.011  
Coupled Cluster CCD   7.391 7.391 7.887 7.699 7.706 7.935 7.647 7.680 7.625       7.616 7.861   7.948 7.969  
CCSD         7.725                            
CCSD(T)                           7.600 7.877   7.981 8.008  
CCSD(T)=FULL         7.643                            
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

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         8.434 7.905 8.413 7.863 8.238 8.237
density functional B3LYP         8.738 8.410 8.719 8.393 8.480 8.470
Moller Plesset perturbation MP2         7.744 7.714 7.737 7.731 7.540 7.537
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.