Crystal morphology prediction of CL-20 and 1,4-DNI co-crystal at different temperatures

Abstract

Using the attachment energy (AE) model and molecular dynamics (MD) methods, the morphologies of hexanitrohexaazaisowurtzitane (CL-20) and 1,4-dinitroimidazole (1,4-DNI) co-crystal under vacuum or solvent at different temperatures were predicted. The CL-20/1,4-DNI co-crystal has six important growth crystal planes: (002), ( 011), ( 101), (11-1), (110), ( 111). The area of ( 002), ( 101), and (011) planes account for a relatively large proportion, which are important crystal planes that affect the crystal morphology. At the same time, by calculating the interaction energy between the solvent and the crystal plane and the attachment energies under the influence of the solvent at 298 K, 320 K, 340 K, 360 K and 380 K were predicted. The crystal habits at different temperatures were simulated. The simulation results showed that the crystal plane attachment energy of CL-20 and 1,4-DNI co-crystal increases with the increase of temperature, indicating that the increase of temperature is conducive to the growth of crystal planes. The aspect ratio decreases with the increase of temperature and the morphology of cocrystal becomes more spherical. The theoretical predictions are in good agreement with the experiment.The simulation results can provide guidance for the crystallization of CL-20/1,4-DNI to obtain a nearly spherical crystal morphology.

Some CL-20 based energetic cocrystals - A review

“…The results showed that the theoretical predictions are in good agreement with the experiment. The simulation results can provide guidance for the crystallization of CL-20/1,4-DNI to obtain a nearly spherical crystal morphology [120].…”

“…In the work of Li et al, the CL-20/1,4-DNI unit cell structure was geometrically optimized by the COMPASS force field [120]. The AE model was used to predict the morphology of CL-20/1,4-DNI under vacuum, resulting in the most morphologically important growth planes.…”