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

Geometry Comparison

C3H4N2 (1H-Pyrazole)


distance is atom 1 (H) to atom 2 (C)

Experimental bond length is 1.082  Å

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Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.089
PM6 1.018
composite G3 1.070
G3B3 1.081
G4 1.079
CBS-Q 1.072

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 1.065 1.065 1.066 1.070 1.070 1.070 1.070 1.070 1.070 1.068 1.043 1.077 1.068 1.075 1.068
density functional LSDA 1.096 1.086 1.086 1.087 1.090 1.089 1.090 1.089 1.087 1.088     1.096 1.086 1.094  
BLYP 1.103 1.084 1.084 1.085 1.088 1.087 1.087 1.086 1.084 1.085     1.094 1.082 1.091  
B1B95 1.093 1.075 1.075 1.076 1.079 1.079 1.079 1.078 1.077 1.077     1.085 1.074 1.082  
B3LYP 1.096 1.076 1.076 1.078 1.081 1.080 1.080 1.079   1.078 1.076 1.042 1.087 1.076    
B3LYPultrafine         1.081   1.080             1.076   1.076
B3PW91   1.077 1.077 1.078 1.081 1.080 1.081 1.080   1.079     1.087 1.077 1.085  
mPW1PW91   1.076   1.076 1.079 1.079 1.079 1.078 1.078 1.078     1.085   1.084  
M06-2X         1.043                      
PBEPBE   1.085     1.089 1.088 1.088 1.087 1.086 1.087 1.085   1.094 1.085    
PBEPBEultrafine         1.090                      
PBE1PBE         1.081                      
TPSSh         1.081   1.081             1.078    
Moller Plesset perturbation MP2   1.079 1.079 1.083 1.081 1.076 1.078 1.081 1.080 1.077   1.042 1.089      
MP2=FULL         1.081 1.075 1.076 1.080                
MP3         1.080   1.075                  
MP3=FULL         1.081   1.075                  
B2PLYP                           1.075    
B2PLYP=FULLultrafine         1.080                      
Configuration interaction CID         1.075                      
CISD         1.075                      
Quadratic configuration interaction QCISD   1.082     1.083       1.081              
Coupled Cluster CCD         1.082                      

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 1.076 1.068 1.073 1.065 1.065
density functional B1B95 1.085 1.089        
B3LYP 1.086 1.089 1.081 1.084 1.080 1.080
Moller Plesset perturbation MP2 1.092 1.090 1.086 1.083 1.085 1.085
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
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