return to home page

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

Geometry Comparison

C2Cl2 (dichloroacetylene)


distance is atom 1 (C) to atom 3 (Cl)

Experimental bond length is 1.612  Å

Display Options
Switch to bar chart display
Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM6 1.704
composite G2 1.648
G3 1.648
G3B3 1.650
G4 1.642

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 aug-cc-pVDZ aug-cc-pVTZ cc-pV(T+d)Z
hartree fock HF 1.705 1.703 1.642 1.703 1.648 1.648 1.648 1.646 1.646 1.641 1.637 1.652 1.651 1.643 1.653 1.643 1.639
density functional LSDA 1.701 1.687 1.624 1.690 1.629 1.629 1.628 1.625 1.625 1.617     1.632 1.620 1.633    
SVWN   1.687     1.629   1.628                    
BLYP 1.735 1.724 1.657 1.726 1.661 1.661 1.661 1.658 1.658 1.649     1.664 1.653      
B1B95 1.710 1.697 1.634 1.699 1.637 1.638 1.638 1.635 1.635 1.629     1.640 1.630 1.641    
B3LYP 1.722 1.710 1.646 1.711 1.650 1.650 1.650 1.647   1.639 1.635 1.652 1.653 1.642 1.654 1.642 1.636
B3LYPultrafine         1.650                     1.644  
B3PW91   1.701 1.637 1.702 1.641 1.641 1.641 1.637   1.631     1.644 1.634      
mPW1PW91   1.697 1.635 1.699 1.638 1.638 1.638 1.635 1.635 1.629     1.641 1.632      
M06-2X         1.646                        
PBEPBE   1.709     1.647 1.647 1.647 1.644 1.643 1.637 1.632   1.649 1.640   1.639  
PBEPBEultrafine         1.647                        
PBE1PBE         1.638                        
HSEh1PBE         1.638                        
TPSSh         1.646   1.646             1.640      
Moller Plesset perturbation MP2   1.736 1.655 1.737 1.644 1.644 1.645 1.641 1.641 1.635   1.649 1.654 1.638 1.657   1.633
MP2=FULL   1.736 1.655 1.737 1.642 1.642 1.642 1.640         1.652 1.633 1.654   1.627
MP3         1.650   1.650                    
MP3=FULL         1.649   1.649                    
MP4   1.744     1.654                        
B2PLYP         1.648                 1.644      
Configuration interaction CID         1.646                        
CISD         1.647                        
Quadratic configuration interaction QCISD   1.743 1.665 1.745 1.654 1.654   1.651 1.651       1.663 1.647      
Coupled Cluster CCD   1.741 1.663 1.743 1.653 1.653   1.649         1.662        
CCSD         1.653                        
CCSD(T)         1.655                 1.649      

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 1.707 1.660 1.702 1.661 1.691 1.697
density functional B1B95 1.715 1.658        
B3LYP 1.725 1.667 1.722 1.668 1.706 1.709
Moller Plesset perturbation MP2 1.747 1.664 1.741 1.663 1.726 1.735
Values that are outliers may reflect incorrect atom numbering for different levels of theory.
Please use the error report form to report problems.