A molecular dynamics simulation of solvent effects on the crystal morphology of HMX

摘要

The solvent has a large effect on the crystal morphology of the organic explosive compound octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX, C_4H_8N_8O_8). The attachment energy calculations predict a growth morphology in vacuum dominated by (020), (011),(102),(111)and(100)crystal forms. Molecular dynamics simulations are performed for these crystal faces of HMX in contact with acetone solvent. A corrected attachment energy model, accounting for the surface chemistry and the associated topography (step structure) of the habit crystal plane, is applied to predict the morphological importance of a crystal surface in solvent. From the solvent-effected attachment energy calculations it follows that the (100) face becomes morphologically more important compared with that in vacuum, while the (020) and (102) are not visible at all. This agrees well with the observed experimental HMX morphology grown from the acetone solution.