return to home page

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

Geometry Comparison

C5H8 (Bicyclo[2.1.0]pentane)


distance is atom 3 (C) to atom 4 (C)

Experimental bond length is 1.565  Å

Display Options
Switch to bar chart display
Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.558
PM6 1.562
composite G2 1.558
G3 1.558
G3B3 1.567
G4 1.567
CBS-Q 2.480

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 1.562 1.583 1.583 1.568 1.558 1.558 1.558 1.558 1.559 1.558 1.556 1.558 1.558 1.556 1.560 1.556
density functional LSDA 1.567 1.572 1.572 1.561 1.548 1.548 1.549 1.546 1.547 1.548     1.548 1.544 1.549  
SVWN   1.572     1.548   1.549                  
BLYP 1.598 1.603 1.603 1.592 1.579 1.579 1.580 1.578 1.579 1.579     1.578 1.576 1.581  
B1B95 1.569 1.580 1.580 1.567 1.553 1.554 1.555 1.553 1.554 1.554     1.553 1.550 1.553  
B3LYP 1.583 1.590 1.590 1.578 1.566 1.566 1.567 1.565   1.567 1.564 1.565 1.566 1.563 1.567  
B3LYPultrafine         1.566   1.567             1.563   1.564
B3PW91   1.584 1.584 1.572 1.559 1.559 1.560 1.559   1.560     1.559 1.557 1.561  
mPW1PW91   1.582 1.582 1.569 1.557 1.557 1.558 1.556 1.557 1.558     1.556 1.554 1.558  
M06-2X         1.558                      
PBEPBE   1.593     1.567 1.567 1.569 1.566 1.567 1.568 1.565   1.567 1.565    
PBEPBEultrafine         1.567                      
PBE1PBE         1.556                      
HSEh1PBE         1.556                      
TPSSh         1.566   1.566             1.563    
Moller Plesset perturbation MP2   1.599 1.599 1.591 1.562 1.559 1.560 1.563 1.564 1.561   1.562 1.566 1.561 1.571  
MP2=FULL   1.598 1.598 1.590 1.560 1.557 1.559 1.561         1.565 1.554    
MP3         1.563   1.563                  
MP3=FULL         1.563   1.563                  
B2PLYP         1.563                 1.562    
B2PLYP=FULLultrafine         1.562                      
Configuration interaction CID   1.592     1.556 1.555 1.556                  
CISD   1.593     1.557 1.555                    
Quadratic configuration interaction QCISD   1.605 1.605 1.595 1.564 1.563 1.564 1.566         1.571      
Coupled Cluster CCD   1.602 1.602 1.593 1.563 1.562 1.563 1.566         1.570      

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 1.579 1.569 1.576 1.566 1.573 1.572
density functional B1B95 1.580 1.569        
B3LYP 1.593 1.582 1.590 1.578 1.582 1.582
Moller Plesset perturbation MP2 1.613 1.577 1.609 1.573 1.607 1.607
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
Please use the error report form to report problems.