return to home page

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

Geometry Comparison

C4H5NO (Isoxazole, 5-methyl-)


distance is atom 1 (C) to atom 5 (C)

Experimental bond length is 1.505  Å

Display Options
Switch to bar chart display
Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.474
PM6 1.464
composite G2 1.490
G3 1.490
G3B3 1.490
G4 1.491

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 1.515 1.488 1.488 1.483 1.490 1.489 1.490 1.489 1.489 1.489 1.487 1.464 1.489 1.487 1.490 1.487
density functional LSDA 1.504 1.471 1.471 1.467 1.471 1.470 1.470 1.466 1.466 1.467     1.470 1.464 1.470  
SVWN   1.455     1.471   1.457                  
BLYP 1.537 1.503   1.498 1.499 1.499     1.497 1.496     1.498 1.494 1.499  
B1B95 1.515 1.484 1.484 1.479 1.482 1.482 1.482 1.480 1.480 1.481     1.481 1.477 1.481  
B3LYP 1.525 1.492 1.492 1.487 1.490 1.489 1.490 1.487   1.487 1.484 1.463 1.489 1.484    
B3LYPultrafine         1.490                     1.488
B3PW91   1.487 1.487 1.482 1.486 1.485   1.483   1.484     1.484 1.481 1.485  
mPW1PW91   1.485   1.480 1.484 1.483 1.483 1.481 1.481 1.482     1.482   1.483  
M06-2X         1.465                      
PBEPBE   1.494     1.491 1.490 1.490 1.487 1.488 1.488 1.485   1.489 1.485    
PBEPBEultrafine         1.491                      
PBE1PBE         1.484                      
HSEh1PBE         1.463                      
TPSSh         1.495   1.494             1.489    
Moller Plesset perturbation MP2   1.502 1.502 1.499 1.487 1.487 1.490 1.488 1.489     1.463 1.492      
MP2=FULL         1.486     1.486                
MP3         1.490   1.491                  
MP3=FULL         1.490   1.490                  
B2PLYP         1.465                 1.483    
B2PLYP=FULLultrafine         1.492                      
Quadratic configuration interaction QCISD   1.486                            

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 1.504 1.508 1.498 1.501 1.490 1.490
density functional B1B95 1.503 1.505        
B3LYP 1.511 1.512 1.504 1.503 1.494 1.494
Moller Plesset perturbation MP2 1.527 1.510 1.517 1.500 1.512 1.512
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
Please use the error report form to report problems.