π–π INTERACTION IN BENZENE DIMER STUDIED USING DENSITY FUNCTIONAL THEORY AUGMENTED WITH AN EMPIRICAL DISPERSION TERM

Abstract

The π–π interactions in various configurations of benzene dimers were studied using a density functional theoretical method augmented with an empirical dispersion term (acronym DFT-D) which is capable of describing long-range dispersive interaction. Compared with the previous CCSD(T) calculations, our approach using PBE functional and polarized triple-ζ quality basis sets provides reasonably accurate binding energies and equilibrium intermolecular geometries of the considered benzene dimer configurations, although the calculations are not counterpoisely corrected. It is expected that our approach can be utilized to evaluate the π–π interactions in large complex systems.