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

Geometry Comparison

C5H8 (Bicyclo[2.1.0]pentane)


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

Experimental bond length is 1.507  Å

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Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.525
PM6 1.541
composite G2 1.513
G3 1.513
G3B3 1.531
G4 1.527
CBS-Q 1.516

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 1.509 1.539 1.539 1.528 1.513 1.513 1.515 1.517 1.515 1.513 1.513 1.513 1.518 1.513 1.520 1.513
density functional LSDA 1.537 1.551 1.551 1.540 1.523 1.523 1.525 1.524 1.523 1.522     1.529 1.519 1.529  
SVWN   1.551     1.523   1.525                  
BLYP 1.563 1.576 1.576 1.565 1.548 1.548 1.551 1.550 1.548 1.547     1.553 1.544 1.554  
B1B95 1.533 1.550 1.550 1.539 1.520 1.521 1.523 1.524 1.522 1.521     1.526 1.518 1.525  
B3LYP 1.544 1.558 1.558 1.549 1.532 1.532 1.534 1.534   1.530 1.529 1.531 1.538 1.530 1.538  
B3LYPultrafine         1.532   1.534             1.530   1.525
B3PW91   1.555 1.555 1.544 1.528 1.527 1.529 1.529   1.526     1.532 1.525 1.533  
mPW1PW91   1.552 1.552 1.541 1.524 1.524 1.526 1.527 1.525 1.523     1.529 1.522 1.530  
M06-2X         1.521                      
PBEPBE   1.568     1.539 1.539 1.541 1.541 1.539 1.538 1.536   1.542 1.537    
PBEPBEultrafine         1.539                      
PBE1PBE         1.524                      
HSEh1PBE         1.524                      
TPSSh         1.527   1.528             1.525    
Moller Plesset perturbation MP2   1.569 1.569 1.561 1.524 1.527 1.531 1.537 1.536 1.531   1.529 1.545 1.527 1.550  
MP2=FULL   1.569 1.569 1.560 1.522 1.525 1.528 1.534         1.543 1.520    
MP3         1.527   1.524                  
MP3=FULL         1.523   1.524                  
B2PLYP         1.530                 1.526    
B2PLYP=FULLultrafine         1.530                      
Configuration interaction CID   1.553     1.516 1.515 1.517                  
CISD   1.555     1.516 1.516                    
Quadratic configuration interaction QCISD   1.572 1.572 1.563 1.529 1.528 1.531 1.537         1.544      
Coupled Cluster CCD   1.568 1.568 1.560 1.526 1.526 1.528 1.534         1.542      

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 1.544 1.529 1.542 1.525 1.536 1.536
density functional B1B95 1.558 1.542        
B3LYP 1.570 1.552 1.568 1.548 1.558 1.559
Moller Plesset perturbation MP2 1.592 1.554 1.583 1.545 1.582 1.581
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
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