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

Geometry Comparison

C5H6 (Bicyclo[2.1.0]pent-2-ene)


distance is atom 1 (C) to atom 3 (C)

Experimental bond length is 1.530  Å

original data displayed. press to display differences
differences displayed. press to display original data

Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.525
PM6 1.525
composite G2 1.518
G3 1.329
G3B3 1.522
CBS-Q 1.330

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 1.532 1.541 1.541 1.529 1.518 1.518 1.518 1.519 1.519 1.519 1.516 1.520 1.521 1.516 1.521 1.516
density functional LSDA 1.533 1.528 1.528 1.518 1.505 1.505 1.506 1.504 1.505 1.505     1.508 1.502 1.507  
SVWN   1.532     1.505   1.513                  
BLYP 1.561 1.553 1.553 1.544 1.531 1.532 1.532 1.531 1.532 1.532     1.534 1.355 1.534  
B1B95 1.536 1.535 1.535 1.525 1.510 1.512 1.512 1.511 1.511 1.512     1.513 1.508 1.512  
B3LYP 1.549 1.543 1.543 1.534 1.522 1.522 1.522 1.522   1.522 1.518 1.525 1.525 1.518    
B3LYPultrafine         1.522                      
B3PW91   1.539 1.539 1.529 1.517 1.517 1.517 1.516   1.517     1.519 1.514 1.518  
mPW1PW91   1.537   1.527 1.514 1.514 1.514 1.514 1.514 1.515     1.516   1.516  
M06-2X         1.522                      
PBEPBE   1.545     1.522 1.522 1.522 1.521 1.522 1.522 1.519   1.524 1.519    
PBEPBEultrafine         1.522                      
HSEh1PBE         1.520                      
Moller Plesset perturbation MP2FC   1.551 1.551 1.543 1.512 1.512 1.512 1.516 1.517     1.519 1.522      
MP2FU   1.551 1.551 1.542 1.511 1.510 1.511 1.515         1.521      
MP3         1.521                      
MP4       1.543                        
B2PLYP         1.524   1.524                  
Configuration interaction CID         1.515                      
CISD         1.337                      
Quadratic configuration interaction QCISD   1.560 1.560 1.551 1.522 1.521 1.522 1.526         1.532      
Coupled Cluster CCD   1.559 1.559 1.550 1.521 1.520 1.521 1.525         1.531      

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 1.540 1.529 1.538 1.526 1.534 1.534
density functional B1B95 1.541 1.528        
B3LYP 1.550 1.537 1.546 1.534 1.540 1.540
Moller Plesset perturbation MP2FC 1.566 1.531 1.557 1.524 1.557 1.557
Values that are outliers may reflect different atom numbering for different levels of theory.
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