National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 22May 2022
NIST Standard Reference Database 101
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XIXIndex of properties
XXH-bond dimers
XXIOddities

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

Calculated Ionization Energy for Al (Aluminum atom)

Experimental Ionization Energy is 5.98577 eV
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  
PM6  
composite G1 5.929
G2MP2 5.881
G2 5.930
G3 5.959
G3B3 5.962
G3MP2 5.938
G4 5.979
CBS-Q 5.915

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) 6-311+G(3df,2pd) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ daug-cc-pVTZ
hartree fock HF -0.590 5.517 5.593 5.500 5.557 5.557 5.557 5.562 5.562 5.602 5.605 5.605 5.548 5.583 5.597 5.607 5.595 5.598 5.607 5.598
ROHF   5.516 5.532 5.500 5.497 5.497 5.498 5.502 5.502   5.501   5.482 5.491 5.490 5.500 5.496 5.492 5.500  
density functional LSDA 0.809 6.489 6.489 6.450 6.455 6.455 6.462 6.456 6.456 6.463 6.457 6.457 6.448 6.460 6.453 6.456 6.466 6.456 6.457  
BLYP 0.204 5.871 5.892 5.859 5.863 5.863 5.875 5.861 5.861 5.875 5.869 5.869 5.856 5.872 5.859 5.869 5.886 5.866 5.870  
B1B95 0.230   5.907 5.866 5.879 5.879 5.885 5.872 5.872 5.885 5.884 5.877 5.860 5.877 5.865 5.880 5.885 5.870 5.881  
B3LYP 0.345 6.022 6.048 6.010 6.017 6.017 6.024 6.014 6.014 6.030 6.022 6.022 6.007 6.026 6.014 6.022 6.035 6.017 6.023  
B3LYPultrafine 0.345 6.022 6.048 6.010 6.017 6.017 6.024 6.014 6.014 6.030 6.022 6.022 6.007 6.026 6.014 6.022 6.035 6.017 6.023  
B3PW91 0.431 6.120 6.156 6.097 6.118 6.118 6.122 6.112 6.112 6.132 6.121 6.121 6.102 6.124 6.116 6.125 6.128 6.118 6.126  
mPW1PW91 0.398 6.104 6.143 6.088 6.113 6.113 6.116 6.105 6.105 6.126 6.117 6.117 6.095 6.117 6.111 6.123 6.122 6.113 6.123  
M06-2X 0.091 5.767 5.788 5.759 5.774 5.774 5.783 5.776 5.776 5.783 5.783 5.782 5.736 5.751 5.749 5.786 5.764 5.757 5.787  
PBEPBE 0.341 6.069 6.102 6.054 6.072 6.072 6.079 6.064 6.064 6.083 6.072 6.072 6.059 6.077 6.066 6.075 6.085 6.070 6.076  
PBEPBEultrafine 0.341 6.069 6.102 6.054 6.072 6.072 6.079 6.064 6.064 6.083 6.072 6.072 6.059 6.077 6.066 6.075 6.085 6.070 6.076  
PBE1PBE 0.328   6.120 6.065 6.088 6.088 6.092 6.082 6.082 6.103 6.092 6.092 6.073 6.095 6.087 6.096 6.099 6.089 6.097  
HSEh1PBE 0.331 6.076 6.115 6.056 6.078 6.078 6.082 6.073 6.073 6.093 6.082 6.082 6.064 6.086 6.077 6.086 6.090 6.079 6.087  
TPSSh 0.418 6.140 6.188 6.117 6.151 6.151 6.153 6.144 6.144 6.162     6.126 6.148 6.143 6.159 6.149 6.144 6.161  
wB97X-D 0.349 6.029 6.060 5.979 5.993 5.993 5.997 5.989 5.989 6.007     5.979 6.004 5.992 5.998 6.010 5.994 6.000  
B97D3   5.972     5.971   5.974   5.966   5.971   5.942   5.955     5.959    
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) 6-311+G(3df,2pd) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ daug-cc-pVTZ
Moller Plesset perturbation MP2 -0.806 5.395 5.681 5.376 5.647 5.647 5.648 5.657 5.657 5.808 5.818 5.818 5.658 5.734 5.817 5.848 5.753 5.823 5.852  
MP2=FULL -0.842 5.393 5.673 5.373 5.640 5.640 5.640 5.650 5.650 5.801 5.797 5.797 5.648 5.732 5.813 5.833 5.751 5.818 5.837  
ROMP2 -0.806   5.676 5.376 5.643 5.643 5.644 5.652 5.652 5.812 5.823   5.653 5.731 5.823   5.751      
MP3 -0.902 5.330 5.716 5.309 5.682 5.682 5.684 5.695 5.695 5.882 5.892 5.892 5.703 5.799 5.895 5.920 5.821 5.900 5.921  
MP3=FULL   5.328 5.707 5.306 5.674 5.674 5.674 5.686 5.686 5.873     5.691 5.796 5.887   5.818 5.891    
MP4 -0.939 5.302 5.732 5.281 5.698 5.698 5.700 5.712 5.712 5.913 5.908 5.924 5.724 5.828 5.928 5.951 5.853 5.933 5.952  
MP4=FULL -0.973 5.301 5.723 5.279 5.689 5.689 5.690 5.703 5.703 5.905 5.904 5.904 5.712 5.824 5.920 5.935 5.849 5.925 5.936  
B2PLYP -0.116 5.735 5.855 5.722 5.823 5.823 5.828 5.823 5.823 5.891 5.888 5.888 5.818 5.861 5.882 5.899 5.874 5.886 5.900  
B2PLYP=FULL -0.128 5.735 5.853 5.722 5.821 5.821 5.826 5.822 5.822 5.890     5.816 5.860 5.882   5.873 5.886    
Configuration interaction CID -0.945 5.292 5.711 5.272 5.677 5.677 5.679 5.689 5.689 5.880 5.889 5.890 5.701 5.805 5.893 5.913 5.830 5.898 5.914  
CISD -0.945 5.292 5.722 5.272 5.688 5.688 5.689 5.700 5.700 5.897 5.907 5.907 5.712 5.818 5.911 5.931 5.845 5.916 5.932  
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) 6-311+G(3df,2pd) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ daug-cc-pVTZ
Quadratic configuration interaction QCISD -0.945 5.292 5.722 5.272 5.688 5.688 5.690 5.700 5.700 5.898 5.908 5.908 5.713 5.818 5.912 5.932 5.846 5.916 5.933  
QCISD(T) -0.945 5.295 5.736 5.275 5.702 5.702 5.704 5.715 5.715 5.925 5.938 5.938 5.728 5.836 5.942 5.966 5.866 5.947 5.967  
QCISD(T)=FULL         5.694   5.695             5.833 5.935 5.951 5.863 5.940 5.953  
QCISD(TQ)=FULL         5.698   5.699             5.840 5.943 5.958 5.870 5.948 5.959  
Coupled Cluster CCD -0.945 5.292 5.711 5.272 5.677 5.677 5.679 5.689 5.689 5.880 5.889 5.890 5.701 5.805 5.894 5.913 5.830 5.898 5.914  
CCSD   5.292 5.721 5.272 5.687 5.687 5.688 5.699 5.699 5.895 5.905 5.905 5.711 5.816 5.909 5.929 5.843 5.914 5.930  
CCSD=FULL -0.976 5.292 5.714 5.271 5.681 5.681 5.682 5.696 5.696 5.891 5.893 5.893 5.704 5.813 5.905 5.917 5.840 5.909 5.918  
CCSD(T)   5.295 5.735 5.275 5.701 5.701 5.703 5.714 5.714 5.923 5.936 5.936 5.727 5.835 5.940 5.964 5.865 5.946 5.965  
CCSD(T)=FULL -0.978 5.294 5.727 5.273 5.693 5.693 5.418 5.706 5.706 5.917 5.919 5.919 5.716 5.832 5.933 5.949 5.861 5.938 5.951  
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) 6-311+G(3df,2pd) 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 5.637 5.718 5.493 5.574 5.674 5.438     5.596
density functional LSDA 6.487 6.503 6.327 6.344 6.539 6.390      
BLYP 5.997 6.026 5.827 5.856 6.054 5.771      
B1B95 5.998 6.021 5.816 5.847 6.053 5.793      
B3LYP 6.141 6.171 5.970 6.000 6.196 5.929     6.014
B3LYPultrafine 6.141 6.171 5.970 6.000 6.196 5.929      
B3PW91 6.223 6.258 6.036 6.074 6.287 6.038      
mPW1PW91 6.210 6.249 6.029 6.070 6.269 6.022      
M06-2X 5.660 5.623 5.375 5.388 5.731 5.704      
PBEPBE 6.171 6.207 5.995 6.033 6.231 5.974     6.065
PBEPBEultrafine 6.171 6.207 5.995 6.033 6.231 5.974      
PBE1PBE 6.180 6.219 6.003 6.044 6.238 5.995      
HSEh1PBE 6.176 6.215 5.999 6.040 6.233 5.987      
wB97X-D 6.105 6.126 5.922 5.946 6.171 5.904      
Moller Plesset perturbation MP2 5.489 5.842 5.361 5.709 5.517 5.319     5.813
MP2=FULL 5.489 5.842 5.361 5.709 5.517 5.308      
MP3 5.415 5.900 5.294 5.771 5.441 5.258      
MP4 5.387 5.928 5.267 5.800 5.413 5.234      
MP4=FULL 5.387 5.928 5.267 5.800 5.413 5.226      
B2PLYP 5.849 5.994 5.695 5.838 5.892 5.649      
Configuration interaction CID 5.384 5.911 5.260 5.776 5.410 5.226      
CISD 5.385 5.925 5.261 5.791 5.411 5.224      
Quadratic configuration interaction QCISD 5.385 5.926 5.262 5.791 5.411 5.224      
QCISD(T) 5.386 5.942 5.265 5.809 5.412 5.228      
Coupled Cluster CCD 5.384 5.911 5.260 5.776 5.410 5.226      
CCSD 5.385 5.924 5.262 5.789 5.411 5.224      
CCSD=FULL 5.385 5.924 5.262 5.789 5.411 5.223      
CCSD(T) 5.386 5.941 5.265 5.808 5.412 5.228      
CCSD(T)=FULL 5.386 5.941 5.265 5.808 5.412 5.221      
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.