The spiral growth model was applied to predict the crystal morphology of 2,2′,4,4′,6,6′-hexanitrostilbene (HNS). We selected solvents of N,N-dimethylformamide (DMF), N-methyl pyrrolidone (NMP), and nitric acid (NA) to control the crystal morphologies of HNS. Molecular dynamic simulations were used to relax the constructed interface model. The relative growth rate of important face is calculated by the spiral growth expression. The predicted crystal shapes are flaky in three solvents. Only (100), (001), and (011) faces are generated in DMF, NMP, and NA. The aspect ratios of the predicted HNS crystal morphologies in DMF, NMP, and NA are 23.00, 15.45, and 4.85, respectively. In addition, we analyzed the properties on each face using periodic bond chain, molecular arrangement, and roughness model. The excellent agreement between the predicted morphologies and the experimental images is clearly evident. These simulation results can provide guidance for the recrystallization of HNS.

Graphical abstract

中文翻译：

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通过分子尺度模拟预测2,2'，4,4'，6,6'-六硝基sti（HNS）的晶体形态。

应用螺旋生长模型预测了2,2'，4,4'，6,6'-六硝基sti（HNS）的晶体形态。我们选择了N，N-二甲基甲酰胺（DMF），N-甲基吡咯烷酮（NMP）和硝酸（NA）的溶剂来控制HNS的晶体形态。使用分子动力学模拟来放松构造的界面模型。重要面的相对增长率通过螺旋增长表达式来计算。预测的晶体形状在三种溶剂中呈片状。在DMF，NMP和NA中仅生成（100），（001）和（011）面。DMF，NMP和NA中预测的HNS晶体形态的长宽比分别为23.00、15.45和4.85。此外，我们使用周期性键链，分子排列和粗糙度模型分析了每个面上的特性。预测的形态和实验图像之间的极好的一致性是显而易见的。这些模拟结果可为HNS的重结晶提供指导。

图形概要