Prediction of crystal morphology of HMX

The crystal morphologies of α- and β-HMX were predicted by using attachment energy (AE) and Bravais-Friedel-Donnary-Harker (BFDH) models. The important crystal surfaces are (020), (011), (10-2), (11-1), (100) for β-HMX and (040), (220) and (111) for α-HMX. The analyses of the crystal surface structures show that (100) and (111) are greatly polar, and (020), (011), (11-1) and (220) are polar, while (10-2) and (040) are non-polar. It can be predicted that (100) and (111) are the important crystal surfaces in the proton solvents with strong polarity, and the appearance area of (020), (011), (11-1) and (220) is increased, and the (10-2) and (040) surfaces diminishes or disappeares, while the contrary cases occurs in the non-polar solvents.