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

Geometry Comparison

C3H4N2 (1H-Imidazole)


distance is atom 5 (C) to atom 6 (H)

Experimental bond length is 1.078  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 1.088
PM6 1.020
composite G3 1.070
G3B3 1.082
CBS-Q 1.073

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 1.079 1.062 1.062 1.064 1.070 1.070 1.070 1.070 1.070 1.070 1.068 1.050 1.077 1.068 1.075 1.068
density functional LSDA 1.096 1.086 1.086 1.087 1.091 1.091 1.091 1.090 1.089 1.089     1.098 1.087 1.095  
BLYP 1.103 1.083 1.083 1.084 1.089 1.088 1.087 1.087 1.085 1.086     1.095 1.083 1.092  
B1B95 1.093 1.074 1.074 1.075 1.080 1.080 1.079 1.079 1.078 1.078     1.086 1.075 1.083  
B3LYP 1.095 1.075 1.075 1.077 1.082 1.081   1.080   1.079 1.077 1.048 1.088 1.077    
B3LYPultrafine         1.082   1.081                  
B3PW91   1.076 1.076 1.077 1.082 1.081 1.081 1.081   1.080     1.088 1.078 1.086  
mPW1PW91   1.074   1.075 1.080 1.080 1.080 1.079 1.078 1.079     1.087   1.084  
M06-2X         1.049                      
PBEPBE   1.084     1.090 1.089 1.089 1.088 1.087 1.088 1.086   1.096 1.086    
PBEPBEultrafine         1.090                      
Moller Plesset perturbation MP2FC   1.077 1.077 1.081 1.082 1.077 1.077 1.081 1.080 1.078   1.047 1.090      
MP2FU         1.081 1.076 1.076 1.081                
MP3         1.081                      
Configuration interaction CID         1.075                      
CISD         1.075                      
Quadratic configuration interaction QCISD   1.080     1.083       1.081              
Coupled Cluster CCD         1.083                      

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 1.070 1.076 1.067 1.072 1.064 1.064
density functional B1B95 1.085 1.089        
B3LYP 1.085 1.090 1.080 1.084 1.079 1.079
Moller Plesset perturbation MP2FC 1.092 1.091 1.085 1.083 1.085 1.084
Values that are outliers may reflect different atom numbering for different levels of theory.
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