The geometries and electronic structures of ethyl nitrate and its dimers have been calculated by using the ab initio method at the HF/6- 31G level for the first time. The total energies have been calculated using 6-311G and 6-311++G basis sets. All the binding energies have been corrected by the basis set superpositio error(BSSE) and zero point energy (ZPE). The greatest corrected dimer bindign energy at the HF/6-31G level is 11.46 kJ.mol^-^1. Charge transfer between two subsystems is small. Based on the vibrational analysis, the changes of thermodynamic properties from mono to dimer have been calculated using the statistical thermodynamic method.

Key words: ETHYL NITRATE, AB INITIO CALCULATION, EXPLOSIVES, THERMODYNAMIC PROPERTIES, INTERMOLECULAR FORCES, NITRIC- ESTER-COMPOUND EXPLOSIVES, INTERACTIONS, ISOMER, ELECTRONIC STRUCTURE