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XVII.C.1.

Calculated Ionization Energy for HNO2 (Nitrous acid)

Experimental Ionization Energy is 11.3 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  
PM6  
composite G4 10.947
CBS-Q 10.882

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
hartree fock HF 7.280     10.452 9.974 9.960 10.080 9.966 9.962 9.810 10.015 9.881 9.890 9.905 10.008 9.938
density functional LSDA 8.609 11.005 11.005 11.330 11.008 11.001 11.302 11.126 11.126 10.884   10.889 11.122   11.252  
SVWN   11.005     11.008   11.302                  
BLYP 8.103 10.375 10.375 10.782 10.429 10.422 10.778 10.550 10.548 10.298   10.311 10.571      
B1B95 8.528 10.868 10.868 11.134 10.540 10.698 10.932 10.763 10.759 10.562   10.598 10.561   10.700  
B3LYP 8.454 10.714 10.714 11.050   10.677 10.963 10.767 10.763 10.545 10.898 10.569 10.763   10.909 10.866
B3LYPultrafine         10.686                      
B3PW91 8.471 10.794 10.794 11.035 10.647 10.636 10.857 10.704 10.700 10.500   10.544 10.664      
mPW1PW91 8.470 10.759 10.797 11.021 10.593 10.581 10.806 10.640 10.667 10.475   10.490 10.599      
M06-2X         10.817                      
PBEPBE 8.149 10.510 10.510 10.816 10.426 10.417 10.722 10.519 10.517 10.297   10.327 10.524      
PBE1PBE         10.564                      
HSEh1PBE         10.564                      
TPSSh             10.741                  
Moller Plesset perturbation MP2   10.754 10.754 11.240 10.741 10.757 11.037 10.661 10.698   10.879 10.556 10.917   11.047  
MP2=FULL   10.754       10.749   10.677 10.692     10.552        
MP3         10.727                      
MP3=FULL         10.720   10.951                  
MP4   10.321     10.704                      
B2PLYP         10.558               10.676      
Quadratic configuration interaction QCISD       10.662 10.497 10.513 10.759 10.467 10.499     10.362 10.704      
QCISD(T)         10.529                      
Coupled Cluster CCD       11.121 10.745 10.758 10.984 10.679       10.578 10.888      
CCSD         10.519                      

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 10.471 10.035 10.439 10.025 10.402 10.402
density functional B3LYP     11.207 10.854 11.133 11.121
Moller Plesset perturbation MP2 11.695 11.014 11.644 10.997 11.547 11.550
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.