return to home page Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
You are here: Home > Geometry > Comparisons > Bonds, angles OR Comparisons > Geometry > Bonds, angles

Geometry Comparison

MgO (magnesium oxide)


distance is atom 1 (Mg) to atom 2 (O)

Experimental bond length is 1.749  Å

Display Options
Switch to bar chart display
Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.692
PM6 1.632
composite G2 1.738
G3 1.738
G3B3 1.744
G4 1.736
CBS-Q 1.751

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-pCVDZ cc-pCVTZ daug-cc-pVTZ
hartree fock HF 1.706 1.776 1.728 1.807 1.738 1.738 1.750 1.751 1.751 1.722 1.718 1.780 1.748   1.721   1.727 1.721 1.743 1.716 1.727
density functional LSDA 1.645 1.741 1.721 1.761 1.730 1.730 1.746 1.742 1.742 1.722     1.737 1.728   1.738          
BLYP 1.670 1.767 1.745 1.789 1.755 1.759 1.778 1.772 1.772 1.751           1.769          
B1B95 1.656   1.728 1.771 1.740 1.742 1.757 1.752 1.752 1.733     1.746 1.736   1.748     1.744 1.731  
B3LYP 1.663 1.750 1.730 1.774 1.744 1.744 1.762 1.756   1.736 1.738 1.765 1.749   1.739   1.744 1.740 1.747 1.735  
B3LYPultrafine         1.744                       1.743        
B3PW91   1.750 1.731 1.773 1.742 1.742 1.758 1.754   1.734           1.750          
mPW1PW91   1.747   1.770 1.739 1.739 1.755 1.750 1.750 1.730           1.747          
M06-2X     1.719   1.734           1.729                    
PBEPBE   1.765     1.756 1.756 1.773 1.768 1.768 1.747 1.750   1.762 1.754              
PBEPBEultrafine         1.756                                
PBE1PBE         1.739                                
HSEh1PBE   1.748     1.740   1.756             1.738              
TPSSh         1.745   1.757     1.739       1.743              
wB97X-D     1.725   1.734   1.747   1.744     1.750 1.747 1.732     1.733        
B97D3   1.764     1.754   1.766   1.763   1.749 1.775   1.752     1.758       1.759
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-pCVDZ cc-pCVTZ daug-cc-pVTZ
Moller Plesset perturbation MP2   1.690 1.718 1.727 1.733 1.734 1.759 1.740 1.740 1.740   1.741 1.734 1.737 1.740 1.757 1.746 1.743 1.735 1.737  
MP2=FULL   1.691     1.733 1.733 1.758 1.740         1.734 1.736 1.736 1.753 1.736   1.734 1.735  
MP3         1.811   1.791                            
MP3=FULL         1.790   1.791                            
MP4         1.703     1.709           1.713              
B2PLYP         1.749                 1.746              
B2PLYP=FULLultrafine         1.749               1.754 1.746     1.748        
Configuration interaction CID         1.765     1.772                          
CISD         1.770                                
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-pCVDZ cc-pCVTZ daug-cc-pVTZ
Quadratic configuration interaction QCISD   1.891     1.801   1.808 1.806 1.806       1.809 1.778              
QCISD(T)         1.786     1.795                          
Coupled Cluster CCD         1.780     1.789         1.786 1.770         1.785 1.764  
CCSD         1.795     1.802                          
CCSD(T)   1.775     1.770 1.770 1.791 1.776 1.775   1.760     1.760     1.766   1.772 1.753  
CCSD(T)=FULL         1.768               1.775 1.754         1.769 1.743  
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-pCVDZ cc-pCVTZ daug-cc-pVTZ

Calculated bond length in Å
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD cc-pVTZ-PP aug-cc-pVTZ-PP Def2TZVPP
hartree fock HF 1.841 1.761 1.812 1.743 1.776 1.813     1.725
density functional B1B95 1.795 1.755              
B3LYP 1.803 1.763 1.785 1.753 1.759 1.780     1.739
PBEPBE                 1.748
Moller Plesset perturbation MP2 1.756 1.745 1.737 1.738 1.730 1.740     1.745
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
Please use the error report form to report problems.