National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 22May 2022
NIST Standard Reference Database 101
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XXIOddities

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

Calculated Ionization Energy for SiO (Silicon monoxide)

Experimental Ionization Energy is 11.49 ± 0.2 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 PM3  
composite G2 11.558
G3 11.519
G3B3 11.565
G4 11.600
CBS-Q 11.519

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 cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ daug-cc-pVTZ
hartree fock HF 6.424 9.797 10.072 9.917 10.365 10.365 10.467 10.376 10.376 10.344   10.382 10.252 10.344 10.386 10.370 10.373 10.391 10.374
density functional LSDA 8.785 9.204 11.772 11.972 11.924 11.924 12.069 11.972 11.972 11.888     11.891 11.979   12.051      
BLYP 7.928 10.920 10.936 11.118 11.095 11.095 11.261 11.128 11.128 11.058     11.047 11.147          
B1B95 8.173   11.137 11.269 11.300 11.300 11.424 11.321 11.321 11.260     11.259 11.304          
B3LYP 8.147 11.167 11.209 11.345 11.372 11.372 11.518 11.403 11.403 11.336   11.467 11.323 11.410 11.446 11.490 11.457 11.459  
B3LYPultrafine         11.372                       11.457    
B3PW91 8.241 11.208 11.250 11.377 11.396 11.396 11.516 11.426 11.426 11.352     11.352 11.411          
mPW1PW91 8.199 11.181 11.232 11.350 11.384 11.384 11.506 11.409 11.409 11.339     11.333 11.391          
M06-2X     11.307   11.463           11.556                
PBEPBE 8.100 11.064 11.081 11.259 11.221 11.221 11.364 11.245 11.245 11.179     11.179 11.249          
PBE1PBE         11.350                            
HSEh1PBE   11.140     11.338   11.462             11.352          
TPSSh         11.271   11.391     11.222       11.281          
wB97X-D     11.300   11.447   11.574   11.480     11.513 11.769 11.457     11.491    
B97D3   11.025     11.175   11.309   11.208   11.269 11.257   11.201     11.243   11.243
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 cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ daug-cc-pVTZ
Moller Plesset perturbation MP2 8.074 11.492 11.541 11.660 11.845 11.845 12.007 11.851 11.851 12.008   11.968   12.083 12.219 12.086 12.191 12.262  
MP2=FULL 8.062 11.489 11.533 11.657 11.839 11.839 12.000 11.846 11.846 12.004     11.808 12.080 12.207     12.250  
MP3         11.371                            
MP3=FULL         11.361   11.503                        
MP4         11.699                 11.963          
B2PLYP         11.369                 11.467          
B2PLYP=FULLultrafine         11.369               11.342 11.468     11.531    
Configuration interaction CID   10.619 10.948   11.274     11.275                      
CISD   10.444 10.813 10.611 11.132     11.152                      
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 cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ daug-cc-pVTZ
Quadratic configuration interaction QCISD   10.337 10.766 10.548 11.071 11.071 11.227 11.084 11.084 11.287     11.070 11.333          
QCISD(T)         11.102               11.113 11.411   11.356 11.492    
Coupled Cluster CCD   10.732 11.074 10.907 11.419 11.419 11.577 11.422 11.422 11.622     11.390 11.662   11.633 11.743    
CCSD         11.101                            
CCSD(T)                         11.152 11.440   11.394 11.521    
CCSD(T)=FULL         11.139                            
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 cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ daug-cc-pVTZ

Ionization Energies in eV
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD cc-pVTZ-PP aug-cc-pVTZ-PP Def2TZVPP
hartree fock HF 10.189 10.487 9.977 10.406 10.505 10.039     10.402
density functional B3LYP 11.438 11.403 11.298 11.344 11.668 11.378     11.444
PBEPBE                 11.272
Moller Plesset perturbation MP2 11.813 12.007 11.730 11.974 12.060 11.757     12.123
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.