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

Geometry Comparison

KBr (Potassium Bromide)


distance is atom 1 (K) to atom 2 (Br)

Experimental bond length is 2.821  Å

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Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM6 2.996
composite G2 2.895
G3B3 2.839
G4 2.838

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
hartree fock HF   2.998 2.881 2.967 2.894 2.895 2.930 2.912 2.912 2.892 2.913 2.992
density functional LSDA 2.736 2.901 2.767 2.870 2.783 2.783 2.815 2.757 2.757 2.759    
SVWN   2.901     2.783   2.815          
BLYP   2.988 2.852 2.951 2.868 2.868 2.907 2.857 2.857 2.848    
B1B95         2.838              
B3LYP   2.967 2.839 2.933 2.853 2.853 2.889 2.847 2.847 2.836   2.962
B3LYPultrafine         2.853              
B3PW91   2.963 2.835 2.927 2.844 2.844 2.877 2.834 2.834 2.827    
mPW1PW91   2.955 2.829   2.839 2.839 2.872 2.831 2.831 2.823    
M06-2X         2.834              
PBEPBE   2.966 2.833 2.931 2.846 2.846 2.881 2.829 2.829 2.826    
PBEPBEultrafine         2.846              
PBE1PBE         2.836              
HSEh1PBE         2.837              
TPSSh         2.848   2.881          
Moller Plesset perturbation MP2   3.016 2.908 2.979 2.875 2.868 2.906 2.853 2.853 2.836   3.013
MP2=FULL   3.011 2.875 2.979 2.871 2.865 2.903 2.847        
MP3         2.870   2.877          
MP3=FULL         2.874   2.910          
MP4   3.021     2.869              
B2PLYP         2.854              
Configuration interaction CID   3.017 2.907 2.980 2.872     2.869        
CISD   3.018 2.907 2.981 2.871     2.868        
Quadratic configuration interaction QCISD   3.020 2.910 2.982 2.870 2.870 2.907 2.864        
QCISD(T)         2.869              
Coupled Cluster CCD   3.018 2.909 2.981 2.870 2.870 2.907 2.863        
CCSD         2.870              
CCSD(T)         2.868              
CCSD(T)=FULL         2.865              

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 3.074   3.074   3.015 3.031
density functional B1B95 3.053          
B3LYP 3.069   3.069   2.982 2.998
Moller Plesset perturbation MP2 3.091   3.091   3.017 3.038
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
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