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

Geometry Comparison

PO (Phosphorus monoxide)


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

Experimental bond length is 1.476  Å

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Calculated bond length in Å
Methods with predefined basis sets
semi-empirical AM1 1.436
PM3 1.458
PM6 1.478
composite G2 1.456
G3 1.456
G3B3 1.487
G4 1.476
CBS-Q 1.454

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 aug-cc-pVQZ cc-pV(T+d)Z cc-pCVTZ
hartree fock HF 1.490 1.657 1.532 1.705 1.456 1.456 1.456 1.448 1.448 1.443 1.438 1.459 1.470 1.447 1.440 1.473 1.447 1.440 1.439  
ROHF   1.529 1.532   1.456 1.456 1.456 1.448 1.448     1.459 1.470 1.447 1.440 1.473 1.447 1.440    
density functional LSDA 1.559 1.512 1.512 1.598 1.502 1.502 1.502 1.494 1.494 1.486   1.503 1.517 1.489   1.518 1.489      
SVWN   1.580     1.502 1.502 1.502 1.494 1.494 1.486     1.517 1.489   1.518 1.489      
BLYP 1.576 1.599 1.532 1.619 1.521 1.521 1.521 1.514 1.514 1.504     1.536 1.508   1.537        
B1B95 1.541 1.499 1.499 1.583 1.489 1.489 1.489 1.482 1.482 1.475   1.491 1.504 1.479   1.505 1.478      
B3LYP 1.550 1.575 1.509 1.594 1.499 1.499 1.499 1.492 1.492 1.483 1.478 1.501 1.513 1.487 1.480 1.515 1.487 1.480 1.479  
B3LYPultrafine         1.499               1.513 1.487   1.515 1.487      
B3PW91 1.548 1.573 1.507 1.591 1.496 1.496 1.495 1.488 1.488 1.481     1.510 1.484   1.512        
mPW1PW91 1.542 1.568 1.502 1.586 1.491 1.491 1.491 1.484 1.484 1.477   1.493 1.506 1.480   1.507 1.480      
M06-2X 1.526 1.556 1.493 1.574 1.484 1.484 1.484 1.478 1.478 1.471   1.487 1.497 1.476   1.500 1.476      
PBEPBE 1.571 1.595 1.528 1.615 1.516 1.516 1.516 1.509 1.509 1.501 1.494 1.518 1.532 1.504   1.532 1.504   1.495  
PBEPBEultrafine         1.517               1.532 1.504   1.533 1.504      
PBE1PBE 1.542 1.503 1.503 1.587 1.492 1.492 1.491 1.485 1.485 1.478   1.494 1.507 1.481   1.508 1.481      
HSEh1PBE 1.543 1.570 1.504 1.588 1.492 1.492 1.492 1.485 1.485 1.478   1.495 1.507 1.481   1.509 1.481      
TPSSh         1.490   1.489             1.481            
Moller Plesset perturbation MP2 1.560 1.549 1.532 1.422 1.472 1.472 1.481 1.468 1.468 1.494   1.479 1.481 1.497 1.491 1.544 1.499 1.492 1.490 1.491
MP2=FULL 1.560 1.548 1.532 1.422 1.472 1.472 1.481 1.468 1.468 1.491   1.479 1.481 1.495 1.488 1.543 1.495 1.488 1.487 1.489
ROMP2 1.561 1.531 1.531 1.632 1.517 1.517 1.518 1.504 1.504 1.498   1.518 1.532 1.501   1.540        
MP3         1.471   1.480                          
MP3=FULL         1.480                              
MP4   1.548     1.473     1.470 1.470     1.480 1.555 1.520   1.561        
MP4=FULL   1.548     1.473       1.470       1.553 1.519   1.559 1.504      
B2PLYP         1.508                              
Configuration interaction CID         1.471     1.465                        
CISD         1.473                              
Quadratic configuration interaction QCISD   1.600 1.520 1.627 1.501 1.501 1.504 1.491 1.491 1.486   1.502 1.514 1.488   1.520 1.489   1.480  
QCISD(T)         1.511     1.499                        
Coupled Cluster CCD   1.577 1.505 1.611 1.472 1.472 1.480 1.467 1.467 1.475   1.479 1.481 1.477   1.507 1.479      
CCSD         1.499     1.486                        
CCSD=FULL         1.499             1.498 1.513 1.480 1.470 1.516 1.479 1.470    
CCSD(T)   1.603     1.501 1.501 1.491 1.476 1.476   1.485     1.495         1.487 1.487
CCSD(T)=FULL         1.500             1.485 1.518 1.492 1.483 1.533 1.491 1.482   1.485

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 1.712 1.469 1.711 1.468 1.684 1.670
density functional B1B95 1.592 1.506        
B3LYP 1.597 1.510 1.593 1.510 1.585 1.576
Moller Plesset perturbation MP2 1.421 1.485 1.423 1.489 1.633 1.419
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
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