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

Geometry Comparison

C3H4N2 (1H-Imidazole)


distance is atom 8 (C) to atom 9 (N)

Experimental bond length is 1.364  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 1.393
PM6 1.351
composite G3 1.349
G3B3 1.367
CBS-Q 1.350

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 1.384 1.368 1.368 1.363 1.349 1.349 1.350 1.349 1.349 1.347 1.346 1.329 1.350 1.346 1.351 1.346
density functional LSDA 1.398 1.376 1.376 1.373 1.360 1.359 1.361 1.357 1.357 1.356     1.360 1.354 1.360  
BLYP 1.423 1.398 1.398 1.394 1.381 1.381 1.383 1.380 1.380 1.377     1.382 1.376 1.382  
B1B95 1.397 1.378 1.378 1.374 1.358 1.360 1.360 1.358 1.358 1.356     1.360 1.354 1.359  
B3LYP 1.407 1.384 1.384 1.381 1.367 1.367   1.366   1.364 1.363 1.333 1.368 1.363    
B3LYPultrafine         1.367   1.368                  
B3PW91   1.381 1.381 1.377 1.363 1.363 1.364 1.362   1.360     1.363 1.358 1.364  
mPW1PW91   1.378   1.374 1.360 1.360 1.361 1.359 1.359 1.357     1.361   1.361  
M06-2X         1.332                      
PBEPBE   1.391     1.373 1.373 1.375 1.372 1.372 1.370 1.369   1.374 1.369    
PBEPBEultrafine         1.373                      
Moller Plesset perturbation MP2FC   1.394 1.394 1.392 1.366 1.366 1.368 1.366 1.366 1.362   1.333 1.370      
MP2FU         1.365 1.364 1.367 1.365                
MP3         1.364                      
Configuration interaction CID         1.355                      
CISD         1.356                      
Quadratic configuration interaction QCISD   1.395     1.366       1.366              
Coupled Cluster CCD         1.364                      

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 1.376 1.360 1.373 1.358 1.370 1.370
density functional B1B95 1.388 1.372        
B3LYP 1.397 1.380 1.394 1.378 1.387 1.388
Moller Plesset perturbation MP2FC 1.412 1.380 1.404 1.376 1.402 1.402
Values that are outliers may reflect different atom numbering for different levels of theory.
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