Ab initio study on the intermolecular interaction and thermodynamic properties of methyl nitrate dimer

Three stable dimers of methyl nitrate have been obtained and their geometri es have been fully optimized at the BF/6-31G* level. Binding energies have been calculated with correction for the basis set superposition error (BSSE ) and zero point energy (ZPE). The cyclic overlap-type structure, the bindi ng energy of which is 11.97 kJ/mol at the MP4SDTQ/6-31G*// HF/6-31G* level, is the most stable. No intermolecular hydrogen bond was found, and the cha rge transfer between two subsystems is minute. The thermodynamic properties of methyl nitrate and its dimers have been calculated based on the vibrati onal analysis and statistical thermodynamics.