National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 17bSeptember 2015
NIST Standard Reference Database 101
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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 SiH2 (silicon dihydride)

Experimental Ionization Energy is 8.92 ± 0.07 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 G3 9.215
G3B3 9.203
G4 9.222
CBS-Q 9.127

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 5.380 7.977 7.944 7.936 7.910 7.891 7.908 7.921 7.894 7.880   7.918 7.899 7.887 7.905 7.894 7.887
density functional LSDA 7.101 11.663 9.567 9.485 9.543 9.530 9.561 9.573 9.556 9.549   9.562 9.589   9.576 9.584  
SVWN   9.508     9.543   9.561       9.566            
BLYP 6.604 8.856 8.872 8.847 8.859 8.841 8.886 8.902 8.880 8.854   8.872 8.904        
B1B95 6.580 6.934 8.906 8.864 8.902 8.879 8.907 9.009 8.900 8.889   8.908 8.920   8.922    
B3LYP 6.730 9.012 9.033 8.995 9.014 8.995 9.030 9.046 9.023 9.008   9.028 9.048 9.039 9.047 9.046 9.040
B3LYPultrafine         9.015                     9.046  
B3PW91 6.708 8.982 9.007 8.954 8.978 8.963 8.986 8.999 8.976 8.968   8.987 8.992        
mPW1PW91 6.646 8.915 8.959 8.910 8.916 8.901 8.925 8.939 8.933 8.922   8.921 8.929        
M06-2X     8.913   8.913                        
PBEPBE 6.624 8.919 8.948 8.902 8.927 8.910 8.944 8.956 8.932 8.920   8.936 8.954        
PBE1PBE         8.912                        
HSEh1PBE   8.908     8.911               8.928        
TPSSh         8.902   8.908     8.883     8.902        
wB97X-D     9.015   8.995       9.001       9.016     9.011  
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 5.551 8.258 8.473 8.231 8.447 8.491 8.515 8.475 8.549 8.718 8.601 8.644 8.817   8.703 8.840  
MP2=FULL   8.262     8.459 8.504 8.528 8.490 8.564     8.650          
MP3         8.574                        
MP3=FULL         8.581   8.655                    
MP4   8.356     8.621                        
B2PLYP         8.782                        
Configuration interaction CID         8.566     8.584                  
CISD         8.565                        
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   8.375     8.629 8.678 8.701 8.651 8.730     8.847 9.004        
QCISD(T)         8.643             8.870 9.051        
Coupled Cluster CCD   8.367     8.625 8.673 8.696 8.646       8.845 9.005        
CCSD         8.627                        
CCSD(T)                       8.869 9.050        
CCSD(T)=FULL         8.647                        
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 7.976 7.908 7.948 7.917 8.041 7.969
density functional B3LYP 9.016 8.998 8.980 8.994 9.078 9.007
Moller Plesset perturbation MP2 8.252 8.514 8.253 8.558 8.311 8.254
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.