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

Geometry Comparison

HO2 (Hydroperoxy radical)


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

Experimental bond length is 0.971  Å

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Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 0.957
PM6 0.989
composite G2 0.953
G3 0.953
G3B3 0.984
G4 0.975
CBS-Q 0.948

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
hartree fock HF 1.004 0.973 0.973 0.957 0.952 0.950 0.950 0.945 0.947 0.948 0.946   0.952 0.947 0.946 0.950 0.947 0.946
ROHF   0.973 0.973 0.957 0.953 0.949 0.949 0.944         0.952 0.946        
density functional LSDA 1.067 1.023 1.023 1.007 0.998 0.995 0.994 0.993 0.990 0.992     0.997 0.990   0.994    
SVWN   1.023     0.998   0.994                      
BLYP 1.077 1.026 1.026 1.008 0.998 0.994 0.993 0.991 0.989 0.991     0.997 0.988   0.993    
B1B95 1.047 1.004 1.004 0.988 0.978 0.977 0.977 0.973 0.972 0.974     0.979 0.970   0.974    
B3LYP 1.052 1.008 1.008 0.991 0.984 0.981 0.980 0.976   0.978 0.976   0.983 0.975 0.975 0.980 0.976 0.975
B3LYPultrafine         0.984   0.980             0.976     0.974  
B3PW91   1.005 1.005 0.989 0.982 0.978 0.978 0.975   0.976     0.981 0.974   0.978    
mPW1PW91   1.002   0.986 0.979 0.975 0.975 0.972 0.971 0.973     0.978 0.971   0.975    
PBEPBE   1.023     0.997 0.993 0.992 0.990 0.988 0.990 0.987   0.996 0.987     0.988  
PBEPBEultrafine         0.995                          
PBE1PBE         0.980                          
HSEh1PBE         0.980                          
TPSSh         0.957   0.958             0.955        
Moller Plesset perturbation MP2   1.000 1.000 0.989 0.983 0.975 0.977 0.970 0.969 0.972   0.974 0.977 0.971   0.978 0.974  
MP2=FULL   0.999     0.983 0.975 0.976 0.969         0.977     0.978    
MP3         0.978   0.945                      
MP3=FULL         0.955   0.950                      
MP4   1.004 1.004 0.991 0.985 0.975 0.977 0.972         0.978 0.972        
B2PLYP         0.982                 0.954        
B2PLYP=FULLultrafine         0.982                          
Configuration interaction CID   0.994 0.994 0.981 0.974 0.966 0.967 0.961         0.969 0.960        
CISD   0.996 0.996 0.982 0.975 0.967 0.968 0.962         0.970 0.961        
Quadratic configuration interaction QCISD   1.006     0.983   0.975 0.969 0.969       0.977 1.829        
QCISD(T)   1.006 1.006   0.985 0.976 0.977 0.972         0.979 0.972        
Coupled Cluster CCD         0.981     0.967         0.974          
CCSD   1.004 1.004 0.979 0.983 0.974 0.975 0.970         0.977 0.968        
CCSD(T)         1.854 0.976   0.972           1.831        

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 0.963 0.957 0.959 0.953 0.959 0.959
density functional B1B95 0.994 0.983        
B3LYP 0.999 0.988 0.995 0.984 0.995 0.995
Moller Plesset perturbation MP2 0.997 0.988 0.994 0.984 0.994 0.994
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
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