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

Geometry Comparison

C3H4N2 (1H-Pyrazole)


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

Experimental bond length is 1.083  Å

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Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.088
PM6 1.020
composite G3 1.071
G3B3 1.082
G4 1.081
CBS-Q 1.074

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 1.081 1.064 1.064 1.065 1.071 1.071 1.071 1.071 1.071 1.071 1.070 1.044 1.078 1.069 1.077 1.069
density functional LSDA 1.097 1.086 1.086 1.087 1.091 1.091 1.091 1.090 1.089 1.089     1.097 1.087 1.095  
BLYP 1.104 1.084 1.084 1.086 1.089 1.088 1.088 1.087 1.086 1.087     1.095 1.083 1.093  
B1B95 1.094 1.075 1.075 1.076 1.080 1.080 1.080 1.080 1.079 1.079     1.087 1.076 1.084  
B3LYP 1.096 1.077 1.077 1.078 1.082 1.082 1.081 1.081   1.080 1.078 1.043 1.088 1.077    
B3LYPultrafine         1.082   1.081             1.078   1.078
B3PW91   1.077 1.077 1.078 1.083 1.082 1.082 1.081   1.081     1.088 1.079 1.086  
mPW1PW91   1.076   1.076 1.081 1.080 1.080 1.080 1.079 1.079     1.087   1.085  
M06-2X         1.044                      
PBEPBE   1.086     1.090 1.090 1.089 1.089 1.088 1.088 1.086   1.096 1.086    
PBEPBEultrafine         1.091                      
PBE1PBE         1.082                      
TPSSh         1.083   1.082             1.079    
Moller Plesset perturbation MP2   1.078 1.078 1.082 1.082 1.077 1.078 1.081 1.081 1.078   1.042 1.090      
MP2=FULL         1.082 1.076 1.076 1.081                
MP3         1.081   1.076                  
MP3=FULL         1.082   1.075                  
B2PLYP                           1.076    
B2PLYP=FULLultrafine         1.081                      
Configuration interaction CID         1.076                      
CISD         1.076                      
Quadratic configuration interaction QCISD   1.082     1.084       1.082              
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 1.071 1.077 1.068 1.074 1.065 1.065
density functional B1B95 1.086 1.090        
B3LYP 1.087 1.091 1.081 1.085 1.080 1.080
Moller Plesset perturbation MP2 1.093 1.091 1.086 1.083 1.086 1.086
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
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