National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 18October 2016
NIST Standard Reference Database 101
IIntroduction
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
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IXFeedback
XOlder CCCBDB versions
XIIGeometries
XIII Vibrations
XIVReaction data
XVEntropy data
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XVIIIon data
XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers
XXIOddities

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

Calculated Ionization Energy for Be (Beryllium atom)

Experimental Ionization Energy is 9.32263 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 9.441
G2MP2 9.445
G2 9.413
G3 9.458
G3B3 9.471
G3MP2 9.552
G4 9.357
CBS-Q 9.367

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 6.913 8.078 8.078 7.928 8.066 7.930 8.006 8.046 8.046 7.934 8.047 8.047 7.862 8.079 8.045 8.043 8.075 8.044 8.043
density functional LSDA 8.387 9.499 9.499 9.382 9.392 9.392 9.446 9.456 9.456 9.396 9.458 9.458 9.287 9.492 9.456 9.458 9.488 9.456 9.458
SVWN 8.387 9.499 9.499 9.382 9.392 9.392 9.446 9.456 9.456 9.396 9.458 9.458 9.287 9.492 9.456 9.458 9.488 9.456 9.458
BLYP 7.997 9.047 9.047 8.919 8.920 8.920 8.986 8.978 8.978 8.925 8.982 8.982 8.824 9.028 8.977 8.976 9.026 8.977 8.976
B1B95 7.937 8.924 8.924 8.822 8.837 8.837 8.892 8.892 8.892 8.824 8.887 8.893 8.739 8.932 8.898 8.882 8.936 8.892 8.883
B3LYP 8.130 9.179 9.179 9.049 9.049 9.049 9.110 9.113 9.113 9.054 9.116 9.116 8.942 9.161 9.110 9.109 9.158 9.110 9.110
B3LYPultrafine 8.130 9.179 9.179 9.049 9.049 9.049 9.110 9.113 9.113 9.054 9.116 9.116 8.942 9.161 9.110 9.109 9.158 9.110 9.110
B3PW91 8.006 9.053 9.053 8.944 8.951 8.951 8.996 9.002 9.002 8.949 9.002 9.002 8.812 9.042 8.997 9.001 9.038 8.997 9.001
mPW1PW91 7.978 9.021 9.032 8.917 8.912 8.912 8.963 8.972 8.983 8.919 8.984 8.984 8.793 9.020 8.977 8.979 9.016 8.977 8.980
M06-2X 8.144 9.118 8.999 8.999 9.372 8.999 9.064 9.062 9.062 8.988 9.065 9.065 8.910 9.108 9.064 9.057 9.107 9.063 9.057
PBEPBE 7.991 9.044 9.044 8.940 8.948 8.948 9.003 9.002 9.002 8.942 9.004 9.004 8.842 9.043 8.995 8.997 9.040 8.995 8.997
PBEPBEultrafine 7.991 9.044 9.044 8.940 8.948 8.948 9.003 9.002 9.002 8.942 9.004 9.004 8.842 9.043 8.995 8.997 9.040 8.995 8.997
PBE1PBE 7.961 9.018 9.018 8.909 8.916 8.916 8.967 8.977 8.977 8.912 8.978 8.978 8.796 9.015 8.970 8.972 9.012 8.970 8.973
HSEh1PBE 7.957 8.765 9.016 8.905 8.912 8.912 8.962 8.973 8.973 8.908 8.974 8.974 8.791 9.011 8.718 8.968 9.007 8.966 8.968
TPSSh         9.004   9.047     9.001         9.056        
wB97X-D     8.887   8.766   8.818   8.830       8.643 8.818 8.837     8.837  
B97D3   9.301     9.124   9.182   9.216                 9.228  
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 7.560 8.689 8.689 8.561 8.646 8.646 8.709 8.772 8.772 8.702 8.807 8.807 8.491 8.776 8.811 8.844 8.776 8.815 8.846
MP2=FULL 7.567 8.697 8.697 8.569 8.650 8.650 8.713 8.785 8.785 8.708 8.822 8.822 8.493 8.782 8.823 8.866 8.782 8.827 8.869
MP3 7.943 8.995 8.995 8.886 8.933 8.932 8.984 9.044 9.044 8.961 9.051 9.051 8.799 9.052 9.053 9.063 9.049 9.054 9.063
MP3=FULL         8.931   8.983                        
MP4 8.154 9.151 9.150 9.051 9.072 9.071 9.117 9.167 9.167 9.084 9.167 9.167 8.954 9.177 9.168 9.177 9.173 9.169 9.177
MP4=FULL   9.152 9.152 9.053 9.068 9.068 9.114 9.169 9.169 9.084 9.171 9.171 8.951 9.178 9.171 9.187 9.174 9.171 9.187
B2PLYP         8.906                            
Configuration interaction CID 8.313 9.266 9.266 9.173 9.188 9.188 9.226 9.270 9.268 9.197 9.270 9.270 9.062 9.278 9.271 9.279 9.274 9.271 9.279
CISD 8.313 9.273 9.273 9.180 9.196 9.196 9.240 9.282 9.280 9.205 9.284 9.284 9.079 9.290 9.284 9.294 9.286 9.285 9.295
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 8.313 9.273 9.273 9.180 9.196 9.196 9.240 9.282 9.280 9.205 9.284 9.284 9.079 9.290 9.284 9.294 9.286 9.285 9.295
QCISD(T) 8.313 9.272 9.272 9.180 9.196 9.196 9.239 9.281 9.280 9.205 9.284 9.284 9.079 9.290 9.284 9.294 9.286 9.285 9.295
Coupled Cluster CCD 8.313 9.266 9.266 9.173 9.188 9.188 9.226 9.270 9.268 9.197 9.270 9.270 9.062 9.278 9.271 9.279 9.274 9.271 9.279
CCSD   9.272 9.272 9.180 9.196 9.196 9.239 9.281 9.280 9.205 9.284 9.284 9.079 9.290 9.284 9.294 9.286 9.285 9.295
CCSD=FULL   9.270 9.270 9.177 9.188 9.188 9.231 9.271 9.271 9.201 9.277 9.277 9.070 9.289 9.278 9.289 9.285 9.279 9.290
CCSD(T)   9.272 9.272 9.180 9.196 9.196 9.239 9.281 9.280 9.205 9.284 9.284 9.079 9.289 9.284 9.295 9.286 9.284 9.295
CCSD(T)=FULL   9.271 9.271 9.178 9.191 9.191 9.146 9.278 9.278 9.205 9.286 9.286 9.074 9.289 9.284 9.302 9.286 9.285 9.303
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 8.211 8.206 8.065 8.060 8.065 8.034
density functional LSDA 9.464 9.466 9.335 9.337 9.480 9.442
SVWN 9.464 9.466 9.335 9.337 9.480 9.442
BLYP 8.968 8.962 8.837 8.830 9.020 8.967
B1B95 8.942 8.937 8.806 8.801 8.901 8.859
B3LYP 9.133 9.128 8.997 8.991 9.150 9.100
B3LYPultrafine 9.133 9.128 8.997 8.991 9.150 9.100
B3PW91 9.139 9.140 8.997 8.998 9.024 8.976
mPW1PW91 9.068 9.069 8.926 8.927 9.002 8.955
M06-2X 9.167 9.186 9.084 9.101 9.080 9.043
PBEPBE 8.998 8.998 8.862 8.861 9.029 8.980
PBEPBEultrafine 8.998 8.998 8.862 8.861 9.029 8.980
PBE1PBE 9.019 9.020 8.879 8.879 8.999 8.953
HSEh1PBE 9.012 9.011 8.871 8.870 8.995 8.949
Moller Plesset perturbation MP2 8.833 8.931 8.718 8.815 8.676 6.519
MP2=FULL 8.833 8.931 8.718 8.815 8.680 8.653
ROMP2 8.211   8.065   8.065 8.036
MP3 9.163 9.220 9.048 9.102 8.990 8.967
MP4 9.332 9.354 9.213 9.233 9.149 9.126
MP4=FULL 9.332 9.354 9.213 9.233 9.149 9.123
Configuration interaction CID 9.443 9.456 9.317 9.330 9.257 9.233
CISD 9.454 9.467 9.334 9.348 9.269 9.244
Quadratic configuration interaction QCISD 9.454 9.467 9.334 9.348 9.269 9.244
QCISD(T) 9.454 9.467 9.334 9.348 9.269 9.244
Coupled Cluster CCD 9.443 9.456 9.317 9.330 9.257 9.233
CCSD 9.454 9.467 9.334 9.348 9.269 9.244
CCSD=FULL 9.454 9.467 9.334 9.348 9.267 9.237
CCSD(T) 9.454 9.467 9.334 9.348 9.269 9.244
CCSD(T)=FULL 9.454 9.467 9.334 9.348 9.267 9.240
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.