National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 17bSeptember 2015
NIST Standard Reference Database 101
IIntroduction
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
VIInput and output files
VIITutorials and Units
VIIILinks to other sites
IXFeedback
XOlder CCCBDB versions
XIIGeometries
XIII Vibrations
XIVReaction data
XVEntropy data
XVIBibliographic data
XVIIIon data
XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers
XXIOddities

NIST policy on privacy, security, and accessibility.

Please rate our products
© 2013 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved.

The National Institute of Standards and Technology (NIST) is an agency of the U.S. Department of Commerce.

Please send questions, comments, corrections, additions and suggestions to cccbdb@nist.gov.

return to home page

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

Calculated Ionization Energy for Si (Silicon atom)

Experimental Ionization Energy is 8.15169 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 PM6  
composite G1 8.096
G2MP2 8.031
G2 8.098
G3 8.127
G3B3 8.129
G3MP2 8.073
G4 8.140
CBS-Q 8.068

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
hartree fock HF 3.715 7.682 7.678 7.657 7.633 7.633 7.633 7.636 7.636 7.639 7.640 7.640 7.632 7.643 7.641 7.637 7.651 7.640 7.637
ROHF 3.715 7.921 7.848 7.834 7.823 7.823 7.857 7.777 7.777 7.996 8.014 7.824 7.791 7.811 7.851 7.855 7.835 7.941 7.786
density functional LSDA 4.962 6.973 8.700 8.666 8.658 8.658 8.673 8.671 8.671 8.665 8.670 8.670 8.675 8.666 8.675 8.670 8.684 8.678 8.670
SVWN 4.962 8.696 8.700 8.666 8.658 8.658 8.673 8.671 8.671 8.665 8.670 8.670 8.675 8.666 8.675 8.670 8.684 8.678 8.670
BLYP 4.253 7.958 7.957 7.942 7.927 7.927 7.952 7.936 7.936 7.934 7.942 7.942 7.942 7.931 7.935 7.941 7.963 7.947 7.943
B1B95 4.521 6.608 8.085 8.045 8.037 8.037 8.048 8.032 8.032 8.040     8.037 8.040 8.031 8.038 8.054   8.039
B3LYP 4.443 8.141 8.142 8.121 8.106 8.106 8.122 8.111 8.111 8.113 8.114 8.114 8.115 8.113 8.112 8.114 8.134 8.118 8.115
B3LYPultrafine 4.443 8.141 8.142 8.121 8.106 8.106 8.122 8.111 8.111 8.113 8.114 8.114 8.115 8.113 8.112 8.114 8.134 8.118 8.115
B3PW91 4.591 8.289 8.290 8.254 8.244 8.244 8.250 8.247 8.247 8.249 8.245 8.245 8.246 8.253 8.246 8.244 8.260 8.247 8.245
mPW1PW91 4.573 8.276 8.276 8.248 8.237 8.237 8.244 8.240 8.240 8.242 8.241 8.241 8.238 8.242 8.237 8.241 8.252 8.240 8.243
M06-2X 4.342 8.007 7.974 7.980 7.974 7.974 7.986 7.985 7.985 7.982 7.988 7.988 7.980 7.951 7.960 7.984 7.971 7.967 7.984
PBEPBE 4.483 8.217 8.218 8.199 8.190 8.190 8.205 8.194 8.194 8.196 8.198 8.198 8.196 8.191 8.192 8.196 8.211 8.200 8.198
PBEPBEultrafine 4.482 8.217 8.218 8.199 8.190 8.190 8.205 8.194 8.194 8.196 8.198 8.198 8.196 8.191 8.192 8.196 8.211 8.200 8.198
PBE1PBE 4.516 8.252 8.253 8.227 8.216 8.216 8.224 8.219 8.219 8.222 8.220 8.220 8.219 8.221 8.218 8.219 8.231 8.221 8.220
HSEh1PBE 4.509 8.244 8.245 8.216 8.204 8.204 8.212 8.208 8.208 8.210 8.208 8.208 8.207 8.211 8.206 8.207 8.221 8.208 8.208
TPSSh         8.221   8.226     8.225         8.213        
wB97X-D     8.176   8.108       8.112           8.113     8.115  
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
Moller Plesset perturbation MP2 3.503 7.592 7.830 7.569 7.791 7.791 7.792 7.801 7.801 8.017 8.032 8.032 7.871 7.920 8.042 8.070 7.962 8.051 8.076
MP2=FULL 3.482 7.590 7.824 7.566 7.786 7.786 7.787 7.798 7.798 8.017 8.026 8.026 7.862 7.919 8.040 8.062 7.961 8.049 8.067
ROMP2 3.914 6.971 9.026 8.223 8.974 8.974 9.029 8.978 8.978 9.519       9.117 9.492   9.199    
MP3 3.408 7.533 7.839 7.512 7.803 7.803 7.805 7.815 7.815 8.084 8.101 8.101 7.908 7.970 8.112 8.134 8.024 8.120 8.137
MP3=FULL         7.795   7.796                        
MP4 3.368 7.504 7.831 7.485 7.794 7.794 7.796 7.808 7.808 8.092 8.112 8.112 7.904 7.967 8.122 8.146 8.026 8.132 8.149
MP4=FULL 3.348 7.502 7.822 7.482 7.786 7.786 7.788 7.801 7.801 8.086 8.098 8.098 7.891 7.963 8.114 8.131 8.022 8.124 8.134
Configuration interaction CID 3.350 7.486 7.803 7.466 7.766 7.766 7.768 7.779 7.779 8.033 8.050 8.050 7.870 7.931 8.059 8.076 7.983 8.067 8.079
CISD 3.350 7.486 7.804 7.467 7.766 7.766 7.768 7.780 7.780 8.030 8.047 8.047 7.869 7.929 8.057 8.073 7.980 8.063 8.076
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
Quadratic configuration interaction QCISD 3.350 7.487 7.811 7.468 7.772 7.772 7.775 7.787 7.787 8.042 8.060 8.060 7.878 7.939 8.070 8.087 7.991 8.077 8.089
QCISD(T) 3.350 7.488 7.817 7.470 7.779 7.779 7.782 7.794 7.794 8.075 8.097 8.097 7.887 7.948 8.107 8.131 8.008 8.117 8.135
QCISD(TQ) 5.459 7.488 39.937 7.470 36.309 36.199 33.188 96.034 96.171 85.925 -1246.222 -1247.546 49.390 21.067 87.111 -70.520 14.544 -94.946 -213.611
Coupled Cluster CCD 3.350 7.488 7.809 7.467 7.772 7.772 7.774 7.785 7.785 8.044 8.062 8.062 7.878 7.940 8.071 8.089 7.993 8.079 8.091
CCSD 3.350 7.487 7.810 7.468 7.772 7.772 7.775 7.786 7.786 8.043 8.060 8.060 7.878 7.939 8.070 8.087 7.991 8.077 8.090
CCSD=FULL 3.331 7.485 7.804 7.465 7.767 7.767 7.768 7.784 7.784 8.040 8.052 8.052 7.866 7.935 8.064 8.076 7.988 8.071 8.079
CCSD(T) 3.350 7.488 7.817 7.470 7.779 7.779 7.782 7.794 7.794 8.075 8.098 8.098 7.887 7.948 8.107 8.133 8.008 8.117 8.135
CCSD(T)=FULL 3.330 7.486 7.810 7.467 7.773 7.773 7.775 7.788 7.788 8.071 8.087 8.087 7.875 7.945 8.100 8.119 8.004 8.110 8.123
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

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 7.781 7.756 7.658 7.634 8.032 7.645
ROHF 7.929 8.046 8.174 7.926 8.292 7.855
density functional LSDA 8.669 8.667 8.539 8.537 8.916 8.649
SVWN 8.669 8.667 8.539 8.537 8.916 8.649
BLYP 8.034 8.023 7.898 7.888 8.281 7.905
B1B95 8.081 8.074 7.942 7.935 8.341 8.024
B3LYP 8.212 8.201 8.074 8.064 8.466 8.092
B3LYPultrafine 8.212 8.201 8.074 8.064 8.466 8.092
B3PW91 8.338 8.330 8.186 8.179 8.609 8.244
mPW1PW91 8.336 8.327 8.186 8.178 8.600 8.233
M06-2X 7.829 7.801 7.626 7.554 8.042 7.956
PBEPBE 8.283 8.276 8.137 8.131 8.535 8.169
PBEPBEultrafine 8.283 8.276 8.137 8.131 8.535 8.169
PBE1PBE 8.314 8.305 8.167 8.159 8.575 8.209
HSEh1PBE 8.308 8.298 8.161 8.152 8.568 8.198
Moller Plesset perturbation MP2 7.653 7.991 7.557 7.889 7.880 7.552
MP2=FULL 7.653 7.991 7.557 7.889 7.880 7.534
MP3 7.584 8.028 7.498 7.931 7.802 7.493
MP4 7.554 8.024 7.472 7.927 7.768 7.465
MP4=FULL 7.554 8.024 7.472 7.927 7.768 7.448
Configuration interaction CID 7.539 7.995 7.454 7.891 7.752 7.447
CISD 7.541 7.994 7.456 7.890 7.753 7.447
Quadratic configuration interaction QCISD 7.542 8.003 7.458 7.899 7.754 7.448
QCISD(T) 7.543 8.010 7.460 7.910 7.754 7.449
QCISD(TQ) 7.544 28.306 36.356 52.538 7.753 35.722
Coupled Cluster CCD 7.540 8.003 7.455 7.900 7.753 7.448
CCSD 7.542 8.003 7.457 7.900 7.754 7.448
CCSD=FULL 7.542 8.003 7.457 7.900 7.754 7.435
CCSD(T) 7.543 8.011 7.460 7.910 7.754 7.449
CCSD(T)=FULL 7.543 8.011 7.460 7.910 7.754 7.434
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.