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

Geometry Comparison

C4H6O (Cyclobutanone)


distance is atom 2 (C) to atom 3 (C)

Experimental bond length is 1.527  Å

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Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.528
PM6 1.525
composite G3 1.527
G3B3 1.540
G4 1.540
CBS-Q 1.530

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 1.549 1.543 1.543 1.522 1.527 1.526 1.525 1.528 1.527 1.529 1.525 1.526 1.528 1.525 1.528 1.525
density functional LSDA 1.567 1.543 1.543 1.522 1.522 1.522 1.518 1.520 1.520 1.522     1.523 1.516 1.519  
SVWN   1.542     1.522   1.518                  
BLYP 1.603 1.578 1.578 1.555 1.555 1.554 1.551 1.555 1.554 1.555     1.556 1.549 1.552  
B1B95 1.567 1.549 1.549 1.527 1.527 1.528 1.525 1.528 1.527 1.529     1.528 1.522 1.524  
B3LYP 1.581 1.560 1.560 1.539 1.540 1.539 1.536 1.539   1.540 1.534 1.535 1.541 1.534    
B3LYPultrafine         1.540                 1.535   1.535
B3PW91   1.554 1.554 1.533 1.534 1.533 1.530 1.533   1.535     1.534 1.529 1.532  
mPW1PW91   1.550 1.550 1.530 1.531 1.530 1.531 1.530 1.529 1.532     1.531   1.529  
M06-2X         1.533                      
PBEPBE   1.567     1.544 1.543 1.540 1.543 1.542 1.544 1.537   1.544 1.538    
PBEPBEultrafine         1.545                      
PBE1PBE         1.530                      
HSEh1PBE         1.530                      
TPSSh         1.541   1.538             1.536    
Moller Plesset perturbation MP2   1.572 1.572 1.551 1.537 1.533 1.532 1.538 1.539     1.534 1.544 1.534    
MP2=FULL   1.571 1.571 1.551 1.535 1.531 1.529 1.536         1.543 1.527    
MP3         1.533   1.535                  
MP3=FULL         1.535   1.533                  
MP4       1.551                        
B2PLYP         1.537                 1.535    
B2PLYP=FULLultrafine         1.539                      
Quadratic configuration interaction QCISD   1.575   1.554 1.537 1.537             1.547      
Coupled Cluster CCD       1.550 1.534                      

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 1.539 1.541 1.535 1.537 1.528 1.529
density functional B1B95 1.547 1.545        
B3LYP 1.559 1.556 1.555 1.553 1.545 1.545
Moller Plesset perturbation MP2 1.577 1.553 1.570 1.546 1.567 1.567
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
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