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

Geometry Comparison

PO2 (Phosphorus dioxide)


distance is atom 1 (P) to atom 2 (O)

Experimental bond length is 1.467  Å

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Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.458
PM6 1.470
composite G2 1.445
G3 1.445
G3B3 1.491
G4 1.465

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 cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
hartree fock HF 1.554 1.556 1.456 1.583 1.445 1.445 1.446 1.437 1.437 1.432 1.428 1.449 1.464 1.438 1.431 1.468 1.439 1.429
ROHF 1.540 1.536 1.449 1.559 1.441 1.441 1.441 1.432 1.432 1.428     1.458 1.434   1.461 1.434  
density functional LSDA 1.599 1.581 1.500 1.605 1.493 1.493 1.494 1.485 1.485 1.475     1.513 1.483   1.514    
SVWN   1.581     1.493   1.494                      
BLYP 1.625 1.607 1.522 1.634 1.514 1.514 1.516 1.507 1.507 1.496     1.535 1.504   1.536    
B1B95 1.680 1.575 1.492 1.599 1.481 1.483 1.484 1.476 1.476 1.469     1.503 1.472   1.502    
B3LYP 1.565 1.583 1.500 1.609 1.491 1.491 1.493 1.484   1.474 1.470 1.496 1.511 1.482   1.513 1.482 1.471
B3LYPultrafine         1.491   1.493             1.481     1.470  
B3PW91   1.580 1.496 1.605 1.487 1.487 1.488 1.480   1.471     1.506 1.478   1.508    
mPW1PW91   1.575 1.491 1.600 1.482 1.482 1.483 1.475 1.475 1.467     1.501 1.473   1.504    
M06-2X         1.475                          
PBEPBE   1.601     1.508 1.508 1.509 1.501 1.501 1.492 1.486   1.528 1.498     1.499  
PBEPBEultrafine         1.508                          
PBE1PBE         1.483                          
HSEh1PBE         1.483                          
TPSSh         1.479   1.479             1.472        
Moller Plesset perturbation MP2   1.575 1.499 1.599 1.493 1.493 1.496 1.481 1.481 1.477   1.497 1.510 1.483   1.519   1.474
MP2=FULL   1.575 1.499 1.599 1.492 1.492 1.496 1.481         1.509 1.480   1.517   1.471
MP3         1.474   1.467                      
MP3=FULL         1.467                          
MP4         1.509                 1.496        
B2PLYP         1.495                 1.472        
Configuration interaction CID   1.562 1.477   1.468     1.455                    
CISD   1.573 1.481   1.471     1.458                    
Quadratic configuration interaction QCISD   1.608 1.500 1.644 1.489 1.489 1.491 1.475         1.508 1.475        
QCISD(T)         1.497                          
Coupled Cluster CCD   1.568 1.485 1.594 1.478 1.478 1.481 1.465         1.495          
CCSD         1.484                          
CCSD(T)         1.495                 1.483        

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 1.587 1.465 1.582 1.462 1.572 1.566
density functional B1B95 1.609 1.502        
B3LYP 1.618 1.509 1.613 1.508 1.603 1.595
Moller Plesset perturbation MP2 1.609 1.513 1.604 1.512 1.597 1.589
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
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