National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 18October 2016
NIST Standard Reference Database 101
IIntroduction
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
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XOlder CCCBDB versions
XIIGeometries
XIII Vibrations
XIVReaction data
XVEntropy data
XVIBibliographic data
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 NH2CONH2 (Urea)

Experimental Ionization Energy is 9.7 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 PM6  
composite G3B3 9.708
G4 9.643

Ionization Energies in eV
Methods with standard basis sets
3-21G 3-21G* 6-31G* 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) TZVP cc-pVDZ cc-pVTZ aug-cc-pVTZ
hartree fock HF     7.901         9.644      
density functional SVWN 9.815     10.579       10.226      
BLYP     8.884                
B3LYP             9.191 9.457     9.586
M06-2X   -24.041 9.990                
PBE1PBE     9.217                
HSEh1PBE 10.804   10.807             11.012  
TPSSh     9.308 9.625     9.007     9.242  
wB97X-D   8.922 9.355 9.638   9.488   9.583 9.638 9.485 9.575
B97D3 8.730   9.065     9.212          
3-21G 3-21G* 6-31G* 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) TZVP cc-pVDZ cc-pVTZ aug-cc-pVTZ
Moller Plesset perturbation MP2     9.914   10.076     10.318      
MP3       10.120              
MP3=FULL     10.031 10.372              
B2PLYP     9.715             10.069  
3-21G 3-21G* 6-31G* 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) TZVP cc-pVDZ cc-pVTZ aug-cc-pVTZ
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.