MP2 ab initio calculations of the hexafluorobenzene—benzene and —monofluorobenzene complexes

Interaction energies for the C6F6C6H6 and C6F6C6H5F supermolecules have been investigated through pseudopotential SCF-MP2 calculations. For both systems, a minimum in the interaction energy curve was found. For C6F6C6H6 this is in agreement with experimental evidence for the formation of a complex, while for C6F6C6H5F the calculated interaction energy suggests the existence of this less symmetric complex. Well defined minima were obtained for the interaction energy curves only after the inclusion of electron correlation. However, the difference between the stabilization energies of the two complexes is determined by the electrostatic contribution.