Growth and morphology of 1,3,5,7-tetranitro-1,3,5,7-tetraazacy-clooct ane (HMX) crystal

Abstract

Cutting explosive single crystals and obtaining oriented crystal wafers (particularly crystal surfaces) are significant to research microscopic changes in highly explosive crystal wafers in various mechanical response mechanisms. Crystals have been cultivated to investigate the basic characteristics of explosives. In this study, the attachment energy (AE) model was employed to predict 1,3,5,7-tetranitro-1,3, 5,7-tetraazacy-clooct ane (HMX) crystal morphology. The gradient cooling method was used to cultivate HMX crystal in acetonitrile solution. The face of the HMX crystal was defined via X-ray diffraction pattern analysis. Simulation result shows that the predicted morphology of the HMX crystal in acetonitrile solution is dominated by the (0 1 1), (1 1 −1), and (1 0 0) faces calculated via solvent-affected AE using the AE model. The predicted HMX morphology is reasonably consistent with the observed experimental result. The mechanism of solvent effects on the structure of crystal surfaces during the process of cultivating crystals was explained by discussing binding energy and adsorption sites. Molecular modeling (MD) simulation was employed to demonstrate the interaction on the solvent surface. The MD method provides guidance to cultivate HMX crystals with various crystal faces in different solvents and under varying experimental conditions.