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

Geometry Comparison

C4H6 (Bicyclo[1.1.0]butane)


distance is atom 3 (C) to atom 8 (H)

Experimental bond length is 1.093  Å

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Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.095
PM6 1.088
composite G2 1.079
G3 1.078
G3B3 1.090
G4 1.088
CBS-Q 1.081

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 1.083 1.074 1.074 1.075 1.078 1.079 1.079 1.078 1.079 1.078 1.077 1.077 1.086 1.076 1.084 1.076
density functional LSDA 1.099 1.095 1.095 1.096 1.098 1.097 1.098 1.096 1.095 1.096     1.104 1.093 1.101  
SVWN   1.095     1.098   1.098                  
BLYP 1.106 1.094 1.094 1.095 1.097 1.096 1.096 1.094 1.093 1.095     1.103 1.090 1.099  
B1B95             1.087                  
B3LYP 1.098 1.086 1.086 1.088 1.090 1.089 1.089 1.087   1.088 1.084 1.085 1.096 1.084 1.093 1.084
B3LYPultrafine                           1.084   1.084
B3PW91   1.087 1.087 1.088 1.090 1.089 1.089 1.088   1.088     1.095 1.085 1.093  
mPW1PW91   1.086   1.086 1.088 1.087 1.088 1.086 1.086 1.087     1.094 1.084 1.091  
M06-2X         1.088                      
PBEPBE   1.095     1.098 1.097 1.097 1.095 1.095 1.096 1.093   1.103 1.093   1.092
PBEPBEultrafine         1.098                      
PBE1PBE         1.089                      
HSEh1PBE         1.089                      
TPSSh         3.262   3.263             3.252    
Moller Plesset perturbation MP2   1.087 1.087 1.091 3.256 1.084 1.085 1.088 1.088 1.085   1.084 1.097 3.245 1.095  
MP2=FULL   1.087     3.253 1.083 1.084 1.087         1.096 3.233    
MP3         1.088   3.252                  
MP3=FULL         3.258   3.252                  
MP4         1.096                      
B2PLYP         1.088                 3.251    
B2PLYP=FULLultrafine         1.088                      
Configuration interaction CID         1.084                      
CISD         1.084                      
Quadratic configuration interaction QCISD   1.090     1.091     1.090 1.089              
Coupled Cluster CCD         1.090                      

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 1.081 1.085 1.078 1.081 1.075 1.075
density functional B1B95 1.094 1.096        
B3LYP 1.096 1.098 1.090 1.092 1.089 1.089
Moller Plesset perturbation MP2 1.104 1.099 1.095 1.090 1.097 1.096
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
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