Molecular dynamics investigation of the effect of solvent adsorption on crystal habits of hexogen

In this work, a molecular dynamics investigation was performed to study the effect of the solvents acetone and cyclohexanone on the crystal habits of hexogen. The results show that the adsorption energies of hexogen polar faces such as the (002), (210), (111), and (200) faces are larger than that of the nonpolar (020) face. The adsorption interactions of hexogen surfaces with acetone are stronger than those with cyclohexanone. The adsorption interactions consist of van der Waals and electrostatic interactions. The effect of solvents on the crystal growth of hexogen is discussed by comparing the adsorption energy of each crystal face. It may qualitatively predict that if hexogen crystallizes from polar solvents (acetone and cyclohexanone), the morphological importance of polar faces increases, especially in acetone solvent, while the importance of the nonpolar (020) face probably diminishes, even disappears. The theoretical prediction properly explains the different crystal morphologies of hexogen observed experimentally in these two solvents.