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

Geometry Comparison

C3H4N2 (1H-Pyrazole)


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

Experimental bond length is 1.080  Å

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Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.086
PM6 1.016
composite G3 1.069
G3B3 1.080
G4 1.078
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 1.076 1.063 1.063 1.065 1.069 1.069 1.069 1.069 1.069 1.068 1.067 1.043 1.076 1.067 1.075 1.067
density functional LSDA 1.093 1.085 1.085 1.087 1.089 1.088 1.089 1.088 1.086 1.087     1.095 1.085 1.093  
BLYP 1.100 1.083 1.083 1.085 1.087 1.086 1.087 1.086 1.084 1.084     1.093 1.081 1.091  
B1B95 1.090 1.074 1.074 1.076 1.078 1.078 1.078 1.077 1.076 1.077     1.084 1.074 1.082  
B3LYP 1.092 1.075 1.075 1.078 1.080 1.079 1.080 1.079   1.078 1.075 1.042 1.086 1.075    
B3LYPultrafine         1.080   1.080             1.075   1.075
B3PW91   1.076 1.076 1.078 1.081 1.080 1.080 1.079   1.078     1.086 1.077 1.085  
mPW1PW91   1.075   1.076 1.079 1.078 1.078 1.078 1.077 1.077     1.085   1.083  
M06-2X         1.043                      
PBEPBE   1.084     1.088 1.087 1.088 1.087 1.086 1.086 1.084   1.094 1.084    
PBEPBEultrafine         1.088                      
PBE1PBE         1.080                      
TPSSh         1.080   1.080             1.077    
Moller Plesset perturbation MP2   1.078 1.078 1.083 1.080 1.076 1.076 1.080 1.079 1.076   1.041 1.089      
MP2=FULL         1.080 1.075 1.076 1.080                
MP3         1.080   1.074                  
MP3=FULL         1.080   1.073                  
B2PLYP                           1.074    
B2PLYP=FULLultrafine         1.079                      
Configuration interaction CID         1.074                      
CISD         1.074                      
Quadratic configuration interaction QCISD   1.081     1.082       1.080              
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 1.070 1.075 1.067 1.072 1.065 1.065
density functional B1B95 1.084 1.087        
B3LYP 1.085 1.088 1.080 1.083 1.079 1.079
Moller Plesset perturbation MP2 1.092 1.089 1.086 1.082 1.086 1.086
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
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