return to home page Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
You are here: Home > Geometry > Experimental > Same bond/angle many molecules OR Comparisons > Geometry > Bonds, angles > Same bond/angle many molecules

Comparison of experiment and theory for rBeBe

18 10 23 14 56
Species with coordinate rBeBe
Species Name
Be2 Beryllium diatomic
The small prefix is the number of bonds with completed calculations.
Click on an entry for a histogram of the difference distribution.
rms differences (calculated - experiment) in Å
Methods with predefined basis sets
semi-empirical AM1 1 0.352
PM3 1 0.255
PM6 1 0.956
composite G2 1 0.196
G3 1 0.196
G3B3 1 0.901
G4 1 0.037
CBS-Q 1 0.194

rms differences (calculated - experiment) in Å
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 daug-cc-pVTZ
hartree fock HF 1 1.070 1 2.500 1 2.500 1 2.173 1 2.155 1 2.155 1 3.583 1 3.929 1 3.929 1 2.053   1 2.520 1 3.931 1 4.461 1 4.460 1 4.462 1 4.461 1 4.460 1 0.412
density functional LSDA 1 0.158 1 0.040 1 0.040 1 0.050 1 0.060 1 0.060 1 0.067 1 0.078 1 0.078 1 0.072   1 0.160 1 0.062 1 0.079   1 0.062 1 0.078    
BLYP 1 0.103 1 0.025 1 0.025 1 0.011 1 0.521 1 0.005 1 0.016 1 0.028 1 0.028 1 0.021   1 0.114 1 0.011 1 0.037          
B1B95 1 0.038 1 0.194 1 0.194 1 0.118 1 0.094 1 0.094 1 0.079 1 0.087 1 0.087 1 0.071   1 0.066 1 0.089 1 0.082   1 0.085 1 0.080    
B3LYP 1 0.067 1 0.119 1 0.119 1 0.081 1 0.054 1 0.054 1 0.037 1 0.032 1 0.032 1 0.033 1 0.021 1 0.097 1 0.048 1 0.023 1 0.023 1 0.043 1 0.022 1 0.022  
B3LYPultrafine         1 0.054             1 0.097 1 0.048 1 0.023   1 0.043 1 0.022    
B3PW91 1 0.075 1 0.114 1 0.114 1 0.073 1 0.052 1 0.052 1 0.040 1 0.040 1 0.040 1 0.040   1 0.106 1 0.046 1 0.030          
mPW1PW91 1 0.067 1 0.136 1 0.136 1 0.089 1 0.065 1 0.065 1 0.051 1 0.056 1 0.056 1 0.053   1 0.099 1 0.059 1 0.045   1 0.057 1 0.045    
M06-2X 1 0.069 1 0.453 1 0.451 1 0.341 1 0.307 1 0.307 1 0.288 1 0.287 1 0.287 1 0.271 1 0.454 1 0.015 1 0.309 1 0.288   1 0.294 1 0.283    
PBEPBE 1 0.119 1 0.013 1 0.013 1 0.002 1 0.013 1 0.013 1 0.021 1 0.026 1 0.026 1 0.022 1 0.033 1 0.122 1 0.018 1 0.035   1 0.020 1 0.035    
PBEPBEultrafine         1 0.013             1 0.122 1 0.018 1 0.035   1 0.020 1 0.036    
PBE1PBE 1 0.072 1 0.122 1 0.122 1 0.081 1 0.060 1 0.060 1 0.046 1 0.049 1 0.049 1 0.047   1 0.097 1 0.054 1 0.040   1 0.052 1 0.040    
HSEh1PBE 1 0.074 1 0.440 1 0.112 1 0.073 1 0.053 1 0.053 1 0.040 1 0.041 1 0.041 1 0.040   1 0.100 1 0.047 1 0.448   1 0.045 1 0.033    
TPSSh   1 0.119 1 0.119 1 0.054 1 0.521 1 0.027 1 0.521 1 0.023   1 0.521   1 0.118 1 0.023 1 0.521   1 0.022 1 0.008    
wB97X-D     1 0.521   1 0.521   1 0.521   1 0.521     1 0.521 1 0.521 1 0.521     1 0.521    
B97D3   1 0.521     1 0.521   1 0.521   1 0.521   1 0.521 1 0.422   1 0.521     1 0.423   1 0.423
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 daug-cc-pVTZ
Moller Plesset perturbation MP2 1 1.158 1 1.763 1 1.763 1 1.707 1 0.521 1 1.469 1 1.802 1 0.521 1 1.614 1 0.245   1 0.058 1 1.779 1 0.329 1 0.273 1 1.464 1 0.320 1 0.266  
MP2=FULL 1 1.156 1 1.751 1 1.751 1 1.692 1 1.442 1 1.442 1 1.762 1 0.457 1 0.457 1 0.164   1 0.054 1 1.754 1 0.005 1 0.163 1 1.407 1 0.009 1 0.149  
MP3         1 1.556   1 0.521         1 0.031 1 0.301 1 0.204          
MP3=FULL         1 0.521   1 0.260         1 0.028 1 0.273 1 0.059          
MP4   1 1.934     1 0.143       1 0.163     1 0.013 1 0.175 1 0.108   1 0.183 1 0.107    
MP4=FULL   1 1.920     1 0.119       1 0.145       1 0.157 1 0.098   1 0.163 1 0.096    
B2PLYP 1 0.026 1 0.703 1 0.703 1 0.250 1 0.099 1 0.099 1 0.078 1 0.089 1 0.089 1 0.068   1 0.074 1 0.107 1 0.071   1 0.099 1 0.068    
B2PLYP=FULL 1 0.026 1 0.711 1 0.711 1 0.251 1 0.096 1 0.096 1 0.075 1 0.086 1 0.086 1 0.056   1 0.075 1 0.103 1 0.018   1 0.095 1 0.012    
B2PLYP=FULLultrafine         1 0.451               1 0.437 1 0.456     1 0.455    
Configuration interaction CID   1 2.147 1 2.147 1 2.153 1 1.994     1 2.303                      
CISD   1 2.113 1 2.113 1 2.125 1 1.982     1 2.358                      
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 daug-cc-pVTZ
Quadratic configuration interaction QCISD   1 2.268 1 2.268 1 2.296 1 2.184 1 2.184 1 2.711 1 2.632 1 2.632 1 0.223   1 2.401 1 2.529 1 2.606   1 2.216 1 2.063    
QCISD(T)         1 0.151             1 0.071 1 0.149 1 0.060   1 0.151 1 0.057    
QCISD(TQ)         1 0.074                 1 0.029     1 0.027 1 0.003  
QCISD(TQ)=FULL                           1 0.137 1 0.053   1 0.133 1 0.061  
Coupled Cluster CCD   1 2.350 1 2.350 1 2.357 1 2.229 1 2.229 1 2.610 1 2.582 1 2.582 1 1.672   1 2.384 1 2.484 1 2.129   1 2.125 1 1.918    
CCSD         1 2.492             1 2.396 1 2.508 1 2.273 1 2.090 1 2.205 1 2.053 1 2.021  
CCSD=FULL         1 2.455             1 2.387 1 2.462 1 0.048 1 0.160 1 2.128 1 0.054 1 0.144  
CCSD(T)         1 1.974             1 0.088 1 0.175 1 0.076 1 0.041 1 0.175 1 0.072 1 0.041  
CCSD(T)=FULL         1 0.147             1 0.075 1 0.151 1 0.120 1 0.024 1 0.150 1 0.117 1 0.033  
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 daug-cc-pVTZ

rms differences (calculated - experiment) in Å
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 1 4.471 1 4.470 1 4.471 1 4.462 1 4.471 1 4.471     1 0.521
density functional B1B95 1 0.135                
B3LYP 1 0.167 1 0.131 1 0.148 1 0.101 1 0.091 1 0.096     1 0.521
PBEPBE                 1 0.521
Moller Plesset perturbation MP2 1 2.382 1 1.825 1 2.266 1 0.495 1 2.225 1 2.210     1 0.521
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.