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

Geometry Comparison

P2H4 (H2PPH2)


distance is atom 1 (P) to atom 3 (H)

Experimental bond length is 1.417  Å

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Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.330
PM6 1.457
composite G2 1.402
G3 1.402
G3B3 1.425
G4 1.421
CBS-Q 1.402

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
hartree fock HF 1.381 1.421 1.401 1.426 1.402 1.404 1.403 1.404 1.406 1.405 1.403 1.410 1.416 1.406 1.404 1.417 1.406 1.404 1.404
density functional LSDA 1.416 1.462 1.433 1.467 1.436 1.435 1.435 1.435 1.434 1.432     1.445 1.431   1.444      
SVWN   1.462     1.436   1.435                        
BLYP 1.426 1.461 1.434 1.469 1.438 1.437 1.436 1.436 1.435 1.433     1.447 1.431   1.445      
B1B95 1.407 1.441 1.417 1.447 1.418 1.419 1.419 1.420 1.419 1.417     1.430 1.416   1.428      
B3LYP 1.412 1.446 1.421 1.453 1.425 1.424 1.424 1.424   1.421 1.417 1.426 1.434 1.420 1.417 1.433 1.420 1.417 1.417
B3LYPultrafine         1.425                 1.420     1.419    
B3PW91   1.447 1.422 1.451 1.423 1.423 1.423 1.424   1.421     1.434 1.421   1.433      
mPW1PW91   1.444   1.448 1.420 1.420 1.420 1.421 1.421 1.419     1.431 1.419   1.431      
M06-2X         1.416                            
PBEPBE   1.462     1.437 1.436 1.436 1.437 1.436 1.434 1.429   1.446 1.433     1.433    
PBEPBEultrafine         1.437                            
PBE1PBE         1.422                            
HSEh1PBE         1.423                            
TPSSh         1.419   1.419             1.418          
Moller Plesset perturbation MP2   1.441 1.411 1.449 1.416 1.407 1.406 1.415 1.409 1.411   1.413 1.424 1.411   1.426 1.412   1.408
MP2=FULL   1.441     1.416 1.406 1.405 1.415         1.422           1.404
MP3         1.420   1.407                        
MP3=FULL         1.420   1.406                        
MP4         1.423     1.424           1.416          
B2PLYP         1.418                 1.415          
B2PLYP=FULLultrafine         1.419                            
Configuration interaction CID         1.416     1.416                      
CISD         1.417                            
Quadratic configuration interaction QCISD   1.453     1.424   1.411 1.424         1.425            
QCISD(T)         1.426     1.427                      
Coupled Cluster CCD         1.423     1.423         1.427            
CCSD         1.424     1.424                      
CCSD(T)         1.426 1.412   1.426                      

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 1.438 1.420 1.436 1.420 1.422 1.420
density functional B1B95 1.466 1.441        
B3LYP 1.467 1.441 1.465 1.439 1.451 1.445
Moller Plesset perturbation MP2 1.463 1.436 1.459 1.433 1.441 1.439
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
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