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

Geometry Comparison

BeCl (beryllium chloride)


distance is atom 1 (Be) to atom 2 (Cl)

Experimental bond length is 1.797  Å

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Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.722
PM6 1.828
composite G2 1.817
G3 1.817
G3B3 1.814
G4 1.814
CBS-Q 1.821

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 1.798 1.862 1.837 1.864 1.817 1.817 1.815 1.816 1.817 1.817 1.808 1.837 1.824   1.810   1.815 1.810 1.813
ROHF   1.863 1.838   1.817 1.817 1.815 1.816                      
density functional LSDA 1.790 1.836 1.818 1.840 1.801 1.801 1.799 1.794 1.794 1.799     1.807 1.792   1.806      
SVWN   1.836     1.801   1.799                        
BLYP 1.808 1.857 1.838 1.864 1.824 1.824 1.822 1.818 1.818 1.823     1.827     1.828      
B1B95 1.800 1.848 1.828 1.852 1.809 1.811 1.808 1.807 1.807 1.810     1.816     1.815      
B3LYP 1.800 1.849 1.829 1.854 1.814 1.814 1.812 1.809   1.813 1.802 1.832 1.819   1.803   1.808 1.803 1.805
B3LYPultrafine         1.814                       1.810    
B3PW91   1.850 1.830 1.853 1.812 1.812 1.810 1.808   1.811           1.818      
mPW1PW91   1.848   1.852 1.810 1.810 1.807 1.806 1.807 1.809           1.817      
M06-2X         1.814                            
PBEPBE   1.854     1.818 1.818 1.817 1.815 1.815 1.817 1.806   1.824 1.811          
PBEPBEultrafine         1.818                            
PBE1PBE         1.809                            
HSEh1PBE         1.810                            
TPSSh         1.817   1.816             1.813          
Moller Plesset perturbation MP2   1.864 1.830 1.868 1.799 1.799 1.797 1.803 1.803 1.812   1.832 1.818   1.806 1.831 1.815 1.807 1.811
MP2=FULL   1.863     1.796 1.796 1.794 1.800             1.796 1.827     1.797
MP3         1.798   1.801                        
MP3=FULL         1.799   1.797                        
MP4         1.800     1.804           1.813          
B2PLYP         1.807                 1.810          
Configuration interaction CID         1.799     1.802                      
CISD         1.800                            
Quadratic configuration interaction QCISD   1.867     1.800   1.799 1.804 1.804       1.821 1.812          
QCISD(T)         1.801     1.805                      
Coupled Cluster CCD         1.799     1.802         1.819            
CCSD         1.800     1.804                      
CCSD(T)         1.801 1.801   1.805     1.807   1.821 1.813   1.833 1.816    
CCSD(T)=FULL         1.798               1.819 1.800   1.829 1.802    

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 1.867 1.821 1.866 1.818 1.880 1.865
density functional B1B95 1.871 1.825        
B3LYP 1.875 1.829 1.870 1.824 1.875 1.853
Moller Plesset perturbation MP2 1.881 1.819 1.871 1.810 1.878 1.863
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
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