The Determination of the Opls-Aa Force Field Parameters for Bonded Interactions in Hydrazine Using Ab Initio Methods

Hydrazine is a widely used compound in science and engineering, particularly as a high energy rocket propellant. The molecular modeling of hydrazine can be a highly safe and effective method for predicting its chemical behavior during engineering applications including storage and transport, provided accurate molecular parameters are known. These simulations are essential for engineering design and safety analyses of any process that involves hydrazine. In this study ab initio calculations were used to determine the first OPLS-AA force field parameters for bonded interactions in hydrazine, which can be used in extensive molecular simulation studies. The Gaussian 03 program (Frisch et al.) was used to determine equilibrium geometry data, bond force constants, angle force constants, and torsion parameters with geometry optimizations and single-point energy calculations using second-order Møller-Plesset perturbation theory (MP2), in the 6-31G(d,p) basis. The results are compared with published experimental data and are shown to be in good agreement.