return to home page Computational Chemistry Comparison and Benchmark DataBase Release 18 (October 2016) 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

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 3 0.514
PM3 3 0.609
PM6 2 0.899
composite G2 4 1.140
G3 3 0.428
G3B3 2 1.551
G4 2 0.369
CBS-Q 3 0.426

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 cc-pCVDZ cc-pCVTZ
hartree fock HF 2 0.795 3 1.513 3 1.513 3 1.335 5 1.443 3 1.327 3 2.118 3 2.315 3 2.293 3 1.267 1 0.680 2 1.807 3 3.212 3 2.598 3 2.597 2 3.168 3 2.597 2 3.167    
ROHF   1 0.415 1 0.415 1 0.414 1 0.417 1 0.417 1 0.407 1 0.411 1 0.411     1 0.421 1 0.400 1 0.411 1 0.415 1 0.399 1 0.411 1 0.414    
density functional LSDA 2 0.259 2 0.323 2 0.323 2 0.323 2 0.328 2 0.328 2 0.325 2 0.336 2 0.336 2 0.329   2 0.346 2 0.321 2 0.335   2 0.321 2 0.335      
SVWN   3 0.372     2 0.328 2 0.328 2 0.325 2 0.336 2 0.336 2 0.329   1 0.463 2 0.321 2 0.335   2 0.321 2 0.335      
BLYP 2 0.240 3 0.251 3 0.251 3 0.250 5 0.383 3 0.252 3 0.256 3 0.265 3 0.321 3 0.179   2 0.242 3 0.252 2 0.231   1 0.440        
B1B95 3 0.357 3 0.381 3 0.381 3 0.369 3 0.371 3 0.371 3 0.189 3 0.373 3 0.373 3 0.370   2 0.324 3 0.364 3 0.372   3 0.363 2 0.325      
B3LYP 3 0.356 3 0.374 3 0.374 3 0.369 3 0.371 3 0.371 3 0.366 3 0.373 3 0.373 3 0.263 1 0.021 2 0.329 3 0.260 3 0.373 2 0.326 2 0.317 3 0.265 3 0.266    
B3LYPultrafine         3 0.371             2 0.329 2 0.317 2 0.323   2 0.317 2 0.369      
B3PW91 2 0.241 3 0.365 3 0.365 3 0.362 3 0.364 3 0.364 3 0.361 3 0.367 3 0.367 3 0.259   2 0.328 3 0.358 3 0.367   1 0.437        
mPW1PW91 3 0.358 3 0.368 3 0.277 3 0.364 3 0.366 3 0.366 3 0.361 3 0.368 3 0.367 2 0.317   2 0.327 2 0.313 2 0.318   3 0.359 2 0.319      
M06-2X 2 0.238 2 0.452 4 0.488 2 0.397 3 0.410 2 0.386 2 0.375 2 0.379 2 0.379 2 0.372   2 0.318 2 0.381 2 0.379   2 0.376 2 0.377      
PBEPBE 2 0.242 3 0.170 2 0.208 2 0.208 3 0.172 3 0.172 3 0.175 3 0.180 3 0.314 3 0.173 1 0.033 2 0.240 3 0.305 3 0.182   2 0.213 2 0.223      
PBEPBEultrafine         3 0.172             2 0.240 2 0.211 2 0.222   2 0.213 2 0.223      
PBE1PBE 2 0.242 2 0.323 2 0.323 2 0.317 2 0.318 2 0.318 2 0.314 2 0.319 2 0.319 2 0.317   2 0.327 2 0.312 2 0.318   2 0.312 2 0.319      
HSEh1PBE 2 0.242 3 0.365 2 0.321 2 0.316 3 0.365 2 0.317 2 0.313 2 0.318 2 0.318 2 0.316   2 0.327 2 0.311 3 0.366   2 0.311 2 0.318      
TPSSh   2 0.311 2 0.311 2 0.303 2 0.521 2 0.304 2 0.521 2 0.306   2 0.521   2 0.322 2 0.299 2 0.521   2 0.299 2 0.307      
wB97X-D     2 0.521   2 0.521   2 0.521   2 0.521     2 0.521 2 0.521 2 0.521     2 0.521      
B97D3   2 0.521     2 0.521       2 0.521               2 0.521      
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-pCVDZ cc-pCVTZ
Moller Plesset perturbation MP2 2 0.853 3 1.110 3 1.110 3 1.080 5 0.818 3 0.966 3 1.136 5 0.869 3 0.997 3 0.466   3 0.349 3 1.082 3 0.406 2 0.371 3 0.911 3 0.403 2 0.367 1 0.423 1 0.443
MP2=FULL 2 0.852 3 1.104 2 1.273 2 1.232 3 0.954 3 0.954 3 1.116 3 0.530 3 0.443 2 0.342   2 0.304 3 1.070 3 0.376 2 0.350 2 1.038 4 0.395 2 0.345 1 0.428 1 0.451
ROMP2 1 0.338 1 0.406 1 0.406 1 0.405 1 0.434 1 0.434 1 0.426 1 0.420 1 0.420 1 0.429   1 0.414 1 0.407 1 0.426   1 0.404        
MP3         3 0.970   2 0.521         2 0.300 2 0.368 2 0.346            
MP3=FULL         2 0.521   2 0.366         2 0.301 2 0.359 2 0.333            
MP4   2 1.398     3 0.469     1 0.657 2 0.329     2 0.297 2 0.324 2 0.322   2 0.324 2 0.322      
MP4=FULL   2 1.388     2 0.331       2 0.327       2 0.322 2 0.337   2 0.321 2 0.333      
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      
Configuration interaction CID   2 1.545 2 1.545 2 1.550 3 1.242     3 1.407                        
CISD   2 1.521 2 1.521 2 1.528 3 1.233     2 1.694                        
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-pCVDZ cc-pCVTZ
Quadratic configuration interaction QCISD   3 1.378 2 1.628 2 1.648 3 1.341 2 1.575 3 1.623 3 1.585 2 1.885 2 0.346   2 1.722 2 1.812 2 1.868   2 1.594 2 1.490      
QCISD(T)         2 0.326             2 0.290 2 0.308 2 0.307   2 0.306 2 0.307      
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   2 1.687 2 1.687 2 1.691 3 1.368 2 1.607 2 1.872 3 1.560 2 1.852 2 1.224   2 1.712 2 1.782 2 1.538   2 1.532 2 1.392      
CCSD         3 1.510     1 0.659       2 1.719 2 1.797 2 1.636 2 1.510 2 1.586 2 1.484 2 1.463    
CCSD=FULL         2 1.764             2 1.712 2 1.765 2 0.326 2 0.347 2 1.533 2 0.322 2 0.341    
CCSD(T)         3 1.195 1 0.654   1 0.651     1 0.432 2 0.293 3 0.350 3 0.355 2 0.313 3 0.347 3 0.355 2 0.311 1 0.414 1 0.436
CCSD(T)=FULL         3 0.370             2 0.292 3 0.349 3 0.379 2 0.327 3 0.346 3 0.374 2 0.325 1 0.418 1 0.442
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-pCVDZ cc-pCVTZ

rms differences (calculated - experiment) in Å
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 3 2.597 3 2.596 3 2.600 3 2.597 3 2.601 3 2.611
density functional B1B95 1 0.135          
B3LYP 3 0.315 3 0.310 3 0.351 3 0.359 3 0.356 3 0.416
Moller Plesset perturbation MP2 3 1.403 3 1.098 3 1.347 3 0.454 3 1.323 3 1.336
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.