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

Geometry Comparison

C3H4N2 (1H-Imidazole)


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

Experimental bond length is 1.079  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 1.089
PM6 1.019
composite G3 1.068
G3B3 1.079
CBS-Q 1.071

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 1.063 1.063 1.064 1.068 1.069 1.069 1.068 1.068 1.068 1.067 1.048 1.076 1.066 1.074 1.066
density functional LSDA 1.095 1.085 1.085 1.086 1.089 1.088 1.089 1.088 1.086 1.087     1.095 1.085 1.093  
BLYP 1.102 1.082 1.082 1.084 1.087 1.086 1.086 1.085 1.083 1.084     1.093 1.081 1.090  
B1B95 1.092 1.074 1.074 1.075 1.077 1.077 1.078 1.077 1.076 1.076     1.084 1.073 1.081  
B3LYP 1.094 1.075 1.075 1.077 1.079 1.079   1.078   1.077 1.075 1.046 1.086 1.075    
B3LYPultrafine         1.079   1.079                  
B3PW91   1.076 1.076 1.077 1.080 1.079 1.079 1.079   1.078     1.086 1.076 1.084  
mPW1PW91   1.074   1.075 1.078 1.078 1.078 1.077 1.077 1.077     1.084   1.082  
M06-2X         1.047                      
PBEPBE   1.084     1.088 1.087 1.087 1.086 1.085 1.086 1.084   1.093 1.084    
PBEPBEultrafine         1.088                      
Moller Plesset perturbation MP2FC   1.077 1.077 1.082 1.080 1.075 1.076 1.080 1.079 1.076   1.045 1.088      
MP2FU         1.080 1.074 1.075 1.079                
MP3         1.079                      
Configuration interaction CID         1.074                      
CISD         1.074                      
Quadratic configuration interaction QCISD   1.080     1.081       1.080              
Coupled Cluster CCD         1.081                      

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 1.075 1.067 1.071 1.064 1.064
density functional B1B95 1.084 1.087        
B3LYP 1.084 1.088 1.079 1.082 1.078 1.078
Moller Plesset perturbation MP2FC 1.091 1.089 1.085 1.082 1.084 1.084
Values that are outliers may reflect different atom numbering for different levels of theory.
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