Generating Cocrystal Polymorphs with Information Entropy Driven by Molecular Dynamics-Based Enhanced Sampling
Generating Cocrystal Polymorphs with Information Entropy Driven by Molecular Dynamics-Based Enhanced Sampling
复制标题
基于分子动力学的增强采样驱动的信息熵生成共晶多晶型物
DOI：
10.1021/acs.jpclett.0c02647
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Tuckerman, Mark E.
中科院分区：
文献类型：
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作者：
Song, Hongxing;Vogt-Maranto, Leslie;Wiscons, Ren;Matzger, Adam J.;Tuckerman, Mark E.
考虑到分子间可能的大量取向，预测有机分子共晶体的结构是一项具有挑战性的任务。使用由分子间取向空间分布函数构建的香农信息熵，通过增强的分子动力学来驱动对晶体结构的搜索，可能是绘制假设多态的图景的有效方法。这里，香农熵被用来产生一组集体变量，用于区分间苯二酚和尿素的1：1共晶的多晶型。我们发现，驱动绝热自由能动力学，一种特殊的增强采样方法，与这些熵变量相结合，可以将稳定相转化为交替的多态。密度泛函理论计算证实，由增强分子动力学得到的结构在1 Gpa以上的压力下是稳定的。因此，我们认为，对于具有多个独立分子的体系，增强采样应该被视为晶体结构搜索协议的一个组成部分。
Predicting structures of organic molecular cocrystals is a challenging task when considering the immense number of possible intermolecular orientations. Use of the Shannon information entropy, constructed from an intermolecular orientational spatial distribution function, to drive a search for crystal structures via enhanced molecular dynamics can be an efficient way to map out a landscape of putative polymorphs. Here, the Shannon entropy is used to generate a set of collective variables for differentiating polymorphs of a 1:1 cocrystal of resorcinol and urea. We show that driven adiabatic free energy dynamics, a particular enhanced-sampling approach, combined with these entropy variables, can transform the stable phase into alternate polymorphs. Density functional theory calculations confirm that a structure obtained from the enhanced molecular dynamics is stable at pressures above 1 GPa. We thus show that enhanced sampling should be considered an integral component of crystal structure searching protocols for systems with multiple independent molecules.