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IV.D.1. (XII.C.1.)

Geometry Comparison

C8H8 (cyclooctatetraene)


distance is atom 1 (C) to atom 2 (C)

Experimental bond length is 1.337  Å

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Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.335
PM6 1.339
composite G3 1.324
G3B3 1.342
G4 1.337

Calculated bond length 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 aug-cc-pVDZ aug-cc-pVTZ
hartree fock HF 1.316 1.320 1.320 1.329 1.324 1.323 1.326 1.322 1.322 1.320 1.320 1.320 1.327 1.320 1.328 1.320
density functional LSDA 1.347 1.339 1.339 1.346 1.342 1.342 1.344 1.337 1.337 1.338     1.345 1.334 1.345  
SVWN   1.339     1.342   1.344                  
BLYP 1.362 1.351 1.351 1.359 1.354 1.354 1.357 1.350         1.357 1.346 1.357  
B1B95 1.341 1.335 1.335 1.343 1.337 1.338 1.340 1.335 1.335 1.334     1.340 1.330 1.339  
B3LYP 1.347 1.339 1.339 1.347 1.342 1.342 1.345 1.338   1.338   1.337 1.345 1.335 1.345  
B3LYPultrafine                               1.334
B3PW91   1.339 1.339 1.346 1.341 1.341 1.343 1.338         1.344 1.334 1.344  
mPW1PW91   1.336 1.336 1.343 1.339 1.339 1.341 1.335 1.335       1.341 1.332    
M06-2X         1.337                      
PBEPBE                 1.348 1.348 1.346          
PBE1PBE         1.340                      
HSEh1PBE         1.340                      
TPSSh         1.342   1.343             1.334    
Moller Plesset perturbation MP2   1.350 1.350 1.361 1.348 1.347 1.351 1.349 1.349     1.344 1.357      
MP2=FULL   1.349 1.349 1.361 1.346 1.346 1.349 1.348         1.356      
MP3             1.340                  
MP3=FULL         1.339   1.342                  
B2PLYP         1.344                 1.334    
Configuration interaction CID   1.331     1.329                      
CISD   1.332     1.329                      

Calculated bond length in Å
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 1.355 1.349 1.342 1.331 1.338 1.337
density functional B1B95 1.371 1.367        
B3LYP 1.374 1.368 1.361 1.351 1.356 1.357
Moller Plesset perturbation MP2 1.396 1.377 1.378 1.358 1.376 1.375
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
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