Melting
point is a significant property of energetic materials
especially for melting cast explosives. Theoretical prediction of
melting point is greatly meaningful for design and screening of low-melting-point
candidates for casting medium. Herein, the melting behavior of nitromethane
(NM) at different heating velocities ranging from 1 to 0.02 K/ps was
investigated via molecular dynamics simulation of solid-to-liquid
phase transition as a case study. Simulation results indicate that
stable solid-to-liquid phase transition can occur when the heating
velocity is less than or equal to 0.1 K/ps. The melting point of NM
was predicted to be around 254 K, which is in reasonable agreement
with the experimental value of 245 K. In the melting process, the
structural transition from ordered arrangement to disordered distribution
of NM molecules was observed as a result of the weakening of intermolecular
interactions, leading to the decrease of C–H···O
hydrogen bonds. The results reported here shed light on the important
influence of heating velocity on accurate estimation of melting point
in continuous heating simulations.