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Release 22May 2022
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XVII.C.1. (III.D.6.)

Calculated Ionization Energy for H2S2 (Disulfane)

Experimental Ionization Energy is 9.3 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
composite G2 9.103
G3 9.110
G3B3 9.113
G4 9.097
CBS-Q 9.099
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 cc-pV(T+d)Z aug-cc-pV(T+d)Z cc-pCVTZ daug-cc-pVTZ
hartree fock HF 5.849 9.306 8.556 9.148 8.497 8.488 8.473 8.489 8.481 8.286   8.408 8.382 8.262 8.243 8.365 8.267 8.246 8.234 8.239 8.235 8.265
density functional LSDA 6.133   9.438 9.647 9.404 9.402 9.420 9.441 9.445 9.338   9.409 9.316 9.386   9.408 9.399   9.378 9.391 9.372  
BLYP 5.559 8.985 8.686 8.926 8.673 8.668 8.721 8.759 8.760 8.594   8.692 8.575 8.653   8.703 8.683   8.644 8.674 8.638  
B1B95 6.052   8.976 9.276 8.922 9.087   9.170 8.934 8.824   8.881 8.837 8.834   8.883 8.850   8.821 8.837 8.817  
B3LYP 6.012 9.413 9.019 9.326 8.991 8.986 9.013 9.042 9.042 8.892   8.982 8.895 8.928 8.928 8.981 8.948 8.936 8.915 8.934 8.911  
B3LYPultrafine   9.412     8.990 8.984 9.012 9.041       8.980 8.893 8.926   8.979 8.946   8.913 8.932 8.909  
B3PW91 6.074 9.494 9.092 9.368 9.029 9.024 9.023 9.031 9.031 8.921   8.986 8.950 8.931   8.985 8.940   8.918 8.927 8.913  
mPW1PW91 6.099 9.517 9.090 9.388 9.027 9.022 9.024 9.036 9.035 8.911   8.981 8.946 8.920   8.981 8.933   8.906 8.919 8.902  
M06-2X 6.255 9.629 9.183 9.565 9.181 9.168 9.168 9.186 9.176 9.065 9.060 9.132 9.048 9.079   9.092 9.087   9.066 9.075 9.067  
PBEPBE 5.670 9.161 8.853 9.076 8.818 8.812 8.838 8.863 8.864 8.730   8.798 8.727 8.760   8.809 8.785   8.752 8.777 8.746  
PBEPBEultrafine   9.164     8.818 8.813 8.838 8.864       8.799 8.727 8.760   8.810 8.785   8.752 8.777 8.746  
PBE1PBE 6.018   9.055 9.361 9.001 9.001 8.996 9.010 9.009 8.884   8.951 8.911 8.891   8.948 8.906   8.878 8.892 8.874  
HSEh1PBE 6.010 9.465 9.045 9.346 8.990 8.984 8.987 9.003 9.002 8.876   8.945 8.901 8.886   8.942 8.899   8.872 8.886 8.868  
TPSSh 5.957 9.390 8.997 9.273 8.939 8.932 8.934 8.958 8.953 8.830   8.895 8.852 8.841 8.836 8.886 8.856 8.845 8.830 8.845 8.824  
wB97X-D 6.208 9.625 9.179 9.485 9.109 9.108 9.105 9.100 9.105 8.996   9.066 7.926 8.995 8.992 9.075 9.003 8.998 8.977 8.985 8.972  
B97D3 5.860 9.157 8.824 9.052 8.776 8.772 8.799 8.827 8.828 8.688 8.751 8.771 8.701 8.728 8.732 8.782 8.750 8.742       8.747
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 cc-pV(T+d)Z aug-cc-pV(T+d)Z cc-pCVTZ daug-cc-pVTZ
Moller Plesset perturbation MP2 5.160 8.865 8.654 8.814 8.634 8.670 8.672 8.653 8.708 8.883   8.693 8.677 8.934 9.030 8.887 9.009 9.062 8.922 8.999 8.927  
MP2=FULL 5.151 8.863 8.653 8.813 8.632 8.668 8.670 8.653 8.708 8.881   8.687 8.677 8.926 9.031 8.888 9.001 9.064 8.920 8.996 8.942  
MP3         8.663   8.607         8.725 8.715 8.975         8.963 9.034 8.967  
MP3=FULL   8.984 8.686 8.909 8.659 8.695 8.696 8.675 8.733 8.916   8.717 8.713 8.961   8.916 9.030   8.946 9.016 8.968  
MP4   8.927     8.615       8.687     8.669 8.655 8.943   8.881 9.027   8.933 9.018 8.937  
MP4=FULL   8.925     8.611       8.683       8.652 8.930   8.881 9.014   8.919 9.004 8.940  
B2PLYP 5.719 9.203 8.855 9.130 8.830 8.836 8.854 8.866 8.881 8.837   8.834 8.775 8.871   8.902 8.910   8.858 8.898 8.857  
B2PLYP=FULL 5.716 9.202 8.855 9.130 8.829 8.836 8.853 8.866 8.881 8.836   8.832 8.775 8.868   8.902 8.908   8.856 8.897 8.860  
B2PLYP=FULLultrafine 5.714 9.202 8.853 9.130 8.828 8.834 8.852 8.864 8.880 8.835   8.831 8.773 8.867   8.901 8.907   8.855 8.896 8.859  
Configuration interaction CID   9.073 8.684 8.980 8.647     8.655                     8.805 8.853 8.808  
CISD   9.050 8.667 8.961 8.629     8.639                     8.781 8.830    
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 cc-pV(T+d)Z aug-cc-pV(T+d)Z cc-pCVTZ daug-cc-pVTZ
Quadratic configuration interaction QCISD   8.996 8.690 8.924 8.660 8.693 8.696 8.675 8.729 8.896   8.715 8.703 8.939   8.887 9.003   8.924 8.989 8.927  
QCISD(T)         8.614     8.630       8.666 8.652 8.925   8.869 9.006   8.913 8.995 8.917  
QCISD(T)=FULL         8.610   8.650           8.649 8.913 9.020 8.869 8.993 9.050 8.899 8.980 8.919  
QCISD(TQ)         8.611   8.650           8.648 8.922   8.864            
QCISD(TQ)=FULL         8.607   8.646           8.645                  
Coupled Cluster CCD   9.033 8.719 8.954 8.691 8.725 8.725 8.703 8.758 8.940   8.747 8.736 8.983   8.922 9.047   8.969 9.034 8.973  
CCSD         8.663         8.901   8.719 8.708 8.943 9.027 8.891 9.007   8.928 8.993 8.932  
CCSD=FULL         8.660         8.892   8.712 8.706 8.931 9.020 8.891 8.994   8.915 8.979 8.939  
CCSD(T)         8.617 8.651 8.657 8.633 8.688 8.878   8.669 8.655 8.928 9.030 8.872 9.009 9.060 8.916 8.998 8.920  
CCSD(T)=FULL         8.613             8.661 8.652 8.916 9.023 8.872 8.996   8.903 8.983 8.924  
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 cc-pV(T+d)Z aug-cc-pV(T+d)Z cc-pCVTZ 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 9.080 8.386 9.054 8.380 9.275 9.215     8.231
density functional B3LYP 9.307 8.929 9.270 8.915 9.437 9.358     8.907
PBEPBE                 8.746
wB97X-D 9.390 8.962 9.353 8.949 9.604 9.583      
Moller Plesset perturbation MP2 8.760 8.618 8.764 8.641 8.854 8.777     8.923
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.