Theoretical investigation of the ethylene dimer: Interaction energy and dipole moment

The interaction potential energy and the interaction-induced dipole moment surfaces of the van der Waals C2H4-C2H4 complex has been calculated for a broad range of intermolecular separations and configurations in the approximation of rigid interacting molecules. The calculations have been carried out using high-level ab initio theory with the aug-cc-pVTZ basis set and within the framework of the analytical description of long-range interactions between ethylene molecules. Binding energy for the most stable configuration of the C2H4-C2H4 complex was calculated at the CCSD(T)/CBS level of theory. The harmonic fundamental vibrational frequencies for this complex were calculated at the MP2 level of theory. (C) 2011 Wiley Periodicals, Inc. J Comput Chem, 2012