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

Geometry Comparison

P2H4 (H2PPH2)


distance is atom 1 (P) to atom 4 (H)

Experimental bond length is 1.414  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 1.401
G3 1.401
G3B3 1.423
G4 1.419
CBS-Q 1.401

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 1.380 1.420 1.400 1.423 1.401 1.403 1.403 1.403 1.405 1.404 1.403 1.410 1.416 1.406 1.404 1.417 1.406 1.404 1.404
density functional LSDA 1.415 1.459 1.432 1.463 1.434 1.433 1.433 1.433 1.432 1.431     1.444 1.430   1.443      
SVWN   1.459     1.434   1.433                        
BLYP 1.425 1.458 1.432 1.465 1.436 1.435 1.434 1.434 1.433 1.433     1.446 1.430   1.444      
B1B95 1.406 1.439 1.416 1.443 1.417 1.418 1.418 1.418 1.418 1.417     1.429 1.416   1.428      
B3LYP 1.411 1.444 1.420 1.449 1.423 1.422 1.422 1.422   1.421 1.416 1.425 1.434 1.420 1.417 1.433 1.419 1.417 1.417
B3LYPultrafine         1.423                 1.420     1.418    
B3PW91   1.444 1.421 1.448 1.422 1.421 1.421 1.422   1.421     1.433 1.421   1.433      
mPW1PW91   1.441   1.444 1.419 1.419 1.418 1.419 1.419 1.418     1.431 1.419   1.430      
M06-2X         1.415                            
PBEPBE   1.459     1.435 1.434 1.434 1.435 1.434 1.433 1.429   1.446 1.433     1.432    
PBEPBEultrafine         1.435                            
PBE1PBE         1.420                            
HSEh1PBE         1.421                            
TPSSh         1.416   1.416             1.417          
Moller Plesset perturbation MP2   1.438 1.410 1.445 1.414 1.405 1.405 1.413 1.408 1.410   1.413 1.423 1.411   1.426 1.412   1.409
MP2=FULL   1.438     1.414 1.404 1.404 1.413         1.422           1.404
MP3         1.418   1.406                        
MP3=FULL         1.419   1.404                        
MP4         1.422     1.422           1.416          
B2PLYP         1.417                 1.414          
B2PLYP=FULLultrafine         1.417                            
Configuration interaction CID         1.415     1.414                      
CISD         1.415                            
Quadratic configuration interaction QCISD   1.450     1.422   1.409 1.422         1.424            
QCISD(T)         1.424     1.425                      
Coupled Cluster CCD         1.421     1.421         1.427            
CCSD         1.422     1.422                      
CCSD(T)         1.424 1.411   1.425                      

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 1.434 1.420 1.434 1.420 1.420 1.418
density functional B1B95 1.461 1.440        
B3LYP 1.462 1.439 1.461 1.439 1.448 1.442
Moller Plesset perturbation MP2 1.458 1.434 1.456 1.433 1.439 1.436
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
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