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
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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 C2Cl2 (dichloroacetylene)

Experimental Ionization Energy is 9.9 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
composite G2 10.020
G3 10.006
G4 10.021

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 aug-cc-pVDZ aug-cc-pVTZ
hartree fock HF 8.883 10.060 9.570 9.836 9.226 9.226 9.266 9.263 9.263 9.048   9.304 9.098 9.226 9.129 9.211 9.130
density functional LSDA 9.534 10.597 10.262 10.436 10.089 10.089 10.186 10.249 10.249         10.144 10.194 10.222  
BLYP 8.737 9.764 9.434 9.620 9.272 9.272 9.410 9.459 9.459 9.215       9.320 9.387    
B1B95 9.151   9.873 10.126 9.639 9.672 9.747 9.780 9.780 9.589       9.716 9.662    
B3LYP 9.239 10.228 9.849 10.069 9.656 9.656 9.760 9.804 9.804 9.579   9.805 9.689 9.700 9.726 9.778 9.739
B3LYPultrafine         9.656                       9.739
B3PW91 9.351 10.327 9.944 10.132 9.712 9.712 9.776 9.805 9.805 9.627       9.760 9.733    
mPW1PW91 9.387 10.313 9.962 10.117 9.680 9.680 9.746 9.768 9.812 9.633       9.723 9.691    
M06-2X     10.201   9.988                        
PBEPBE 8.937 9.965 9.628 9.798 9.441 9.441 9.543 9.574 9.574 9.378     9.479 9.487 9.510    
PBE1PBE         9.700                        
HSEh1PBE   10.304     9.679   9.749               9.701    
TPSSh         9.569   9.637     9.492         9.599    
wB97X-D     10.070   9.808   9.867   9.894     9.906   9.867 9.807   9.810
B97D3   9.946     9.389   9.485   9.512   9.451       9.447   9.465
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 aug-cc-pVDZ aug-cc-pVTZ
Moller Plesset perturbation MP2 9.184 10.426 9.985   9.855         10.034   9.995 10.123 9.981 10.155    
MP2=FULL   10.426 9.982   9.841 9.841   9.956 9.956         9.977 10.147    
MP3         9.695                        
MP3=FULL         9.693   9.754                    
MP4   10.217                              
B2PLYP         9.667                   9.804    
Configuration interaction CID         9.610                        
CISD         9.578                        
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 aug-cc-pVDZ aug-cc-pVTZ
Quadratic configuration interaction QCISD   10.119 9.844 9.943 9.593 9.593   9.681 9.681         9.700 9.885    
Coupled Cluster CCD   10.405 9.961 10.253 9.761 9.761   9.848           9.869      
CCSD         9.643                        
CCSD(T)                             9.920    
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 aug-cc-pVDZ aug-cc-pVTZ

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         9.692 9.078   9.278 9.996 9.892
density functional B3LYP         10.010 9.586   9.707 10.221 10.128
Moller Plesset perturbation MP2           9.888     10.515 10.410
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.