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

Geometry Comparison

HClO4 (perchloric acid)


distance is atom 3 (O) to atom 6 (H)

Experimental bond length is 0.980  Å

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Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM6 3.324
composite G2 0.960
G3 0.960
G3B3 0.978
G4 0.972
CBS-Q 0.955

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) TZVP cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ
hartree fock HF 1.005 0.981 0.978 0.965 0.960 0.955 0.955 0.950 0.952 0.951 0.954 0.958 0.951 0.955 0.952 0.951 0.958 0.951
density functional LSDA 1.048 1.016 1.016 1.007 0.990 0.987 0.988 0.985 0.983 0.982 0.985 0.990 0.983 0.987 0.984 0.983 0.990 0.983
SVWN   1.022     0.990 0.987 0.988 0.985 0.983 0.982   0.990 0.983 0.987 0.984 0.983 0.990 0.983
BLYP 1.064 1.028 1.022 1.009 0.993 0.989 0.990 0.986 0.984 0.984 0.986 0.992 0.983     0.983 0.992 0.983
B1B95 1.039 1.001 1.001 0.992 0.977 0.977 0.973 0.970 0.969 0.969 0.971 0.976 0.969 0.973 0.969 0.968 0.976 0.968
B3LYP 1.046 1.013 1.007 0.996 0.982 0.978 0.979 0.975 0.974 0.973 0.975 0.981 0.973 0.977 0.973 0.972 0.981 0.972
B3LYPultrafine         0.982                   0.972      
B3PW91 1.042 1.010 1.004 0.994 0.979 0.975 0.976 0.972 0.972 0.971 0.973 0.979 0.971     0.971 0.979 0.971
mPW1PW91 1.038 1.007 1.001 0.992 0.977 0.973 0.974 0.970 0.969 0.969 0.971 0.977 0.969 0.973 0.970 0.969 0.976 0.969
M06-2X 1.034 1.009 1.003 0.994 0.980 0.976 0.977 0.973 0.972 0.971 0.974 0.978 0.972 0.975 0.972 0.971 0.978 0.971
PBEPBE 1.057 1.025 1.019 1.006 0.990 0.986 0.987 0.984 0.982 0.982 0.984 0.990 0.982 0.986 0.982 0.981 0.989 0.981
PBE1PBE 1.038 1.003 1.003 0.992 0.978 0.978 0.975 0.971 0.970 0.970 0.972 0.977 0.970 0.974 0.971 0.970 0.977 0.970
HSEh1PBE 1.038 1.008 1.002 0.993 0.978 0.974 0.975 0.971 0.970 0.970 0.972 0.977 0.970 0.974 0.971 0.969 0.977 0.970
TPSSh         0.980   0.977           0.973          
Moller Plesset perturbation MP2   1.013 1.005 1.000 0.986 0.978 0.979 0.972 0.971 0.973 0.976 0.980 0.973 0.981 0.975 0.972 0.979 0.972
MP2=FULL   1.013 1.004 1.000 0.986 0.977 0.979 0.972 0.970 0.972 0.976 0.979 0.972 0.980 0.973 0.971 0.979 0.971
MP3         0.981   0.970                      
MP3=FULL         0.979   0.970                      
MP4         0.987       0.972       0.974     0.973   0.972
B2PLYP         3.207                          
Configuration interaction CID   0.999 0.991 0.986 0.972     0.958                    
CISD   0.999 0.991 0.987 0.972     0.959                    
Quadratic configuration interaction QCISD   1.015 1.004   0.984 0.975 0.976 0.970 0.968 0.969 0.973 0.977 0.969 0.977 0.971 0.968 0.977 0.968
QCISD(T)         0.987   3.263   3.232   0.976 0.980 0.972     0.971 0.979 0.971
Coupled Cluster CCD   1.009 1.001 0.996 0.983 0.973 0.974 0.968 0.967 0.968 0.971 0.976 0.967       0.975  
CCSD         0.984             0.977 0.968     0.968 0.977 0.968
CCSD(T)         0.987   3.269   3.228   0.975 0.980 0.972     0.971 0.979 0.971
CCSD(T)=FULL         0.986           0.975 0.979 0.970     0.969   0.969

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 0.970 0.962 0.966 0.959 0.966 0.965
density functional B3LYP 1.004 0.987 0.999 0.982 1.000 1.000
Moller Plesset perturbation MP2 1.008 0.991 1.003 0.987 1.003 1.003
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
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