...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Crystal growth & design >Exploring the Multi-minima Behavior of Small Molecule Crystal Polymorphs at Finite Temperature
【24h】

Exploring the Multi-minima Behavior of Small Molecule Crystal Polymorphs at Finite Temperature

机译：探索小分子晶体多晶型物在有限温度下的多重性行为

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The predicted ambient-temperature crystal structures of organic small molecules are often represented by a single energy-minimized configuration at 0 K. This procedure effectively collapses the ensemble of configurations that would be present at ambient temperature into a single representative structure. This simplification is likely to break down if the crystal structure has multiple different latticeenergy minima within the ambient-temperature ensemble. In this work, we explore the existence of multiple minima within finite-temperature crystal basins by sampling crystals at a range of temperatures followed by rapidly quenching the configurations. We then observe whether each crystal returns to the original minimum or to an ensemble of minima on the lattice-energy landscape. Eight of the twelve compounds examined in this work have at least one polymorph with multi-minima behavior. These multi-minima basins have implications for crystal structure prediction studies, and it is therefore important to understand the factors that lead a crystal structure to have multiple minima. We find that, in general, the existence of multiple minima within a crystal basin is more likely for the compounds that are larger and have more flexibility. We find that the number of minima found tends to increase with the sampling temperature, and the lattice energy of minima found from the same finite-temperature trajectory can vary by >2.0 kJ/mol. Finally, we show that the lattice-energy minima contained within a single ambient-temperature basin can have different space groups and numbers of molecules in the asymmetric unit. Overall, the data suggest that many experimental crystal polymorphs are likely to have multi-minima behavior and are best described by an ensemble of structures encompassing many minima rather than by a single lattice-energy minimum.
机译：有机小分子的预测环境温度晶体结构通常通过单一能量 - 最小化构型表示在0k中。该过程有效地折叠了在环境温度下存在成单个代表性结构的配置的集合。如果晶体结构在环境温度集合中具有多个不同的LatticeEnergy最小值，则这种简化可能会破裂。在这项工作中，我们通过在一系列温度下采样晶体，然后通过快速淬火配置，探讨有限温度晶体池中的多个最小值。然后，我们观察每个晶体是否返回到原始最小最小或在格子 - 能量景观上的最小值的集合。在该工作中检查的十二种化合物中的八个具有至少一种具有多重性行为的多晶型物。这些多项量盆地对晶体结构预测研究具有影响，因此了解导致晶体结构具有多个最小值的因素是重要的。我们发现，通常，水晶盆内内部多个最小值的存在更可能适用于较大并且具有更大的柔韧性的化合物。我们发现发现的最小值数量趋于增加采样温度，并且从相同的有限温度轨迹中发现的最小值的晶格能量可以变化> 2.0kJ / mol。最后，我们表明，在单个环境温度盆地内包含的晶格 - 能量最小值可以具有不同的空间组和非对称单元中的分子数。总的来说，数据表明，许多实验晶体多晶型物可能具有多重性行为，并且最好通过包括许多最小值而不是单个晶格 - 能量最小的结构的整体描述。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号