对于具有软自由度的分子的晶体结构预测,使用从第一原理中衍生出来的体间力场
Rahul Nikhar1, Rafał Podeszwa2, Atta U Rehman1
1Department of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA.
概括
一个新的晶体结构预测 (CSP) 协议有效地使用ab initio力场模型灵活的分子. 这种方法对预测晶体结构,特别是柔性单体的结构有前途,并有助于分子动力学模拟.
科学领域:
- 计算化学计算化学
- 晶体学 晶体学是指结晶学.
- 材料科学 材料科学 材料科学
背景情况:
- 晶体结构预测 (CSP) 对于理解材料特性至关重要.
- 以前的CSP方法面临的挑战是柔性分子和复杂的晶体系统 (例如盐,共晶体).
- 第七次盲测提供了多样化和具有挑战性的目标来评估CSP协议.
研究的目的:
- 介绍和评估一种新的分子晶体结构预测 (CSP) 协议.
- 评估协议在各种目标上的表现,包括柔性单体,盐和共晶.
- 调查一开始力场 (aiFF) 对CSP的实用性.
主要方法:
- 开发了一种初始的两体刚性单体六维力场 (aiFF) 用于全球最小合规者.
- 采用一个CSP协议,涉及结构搜索,包装和格子能量最小化.
- 用灵活的单体CSP和实证/重对称的分子内力场 (FFs) 针对特定的目标.
主要成果:
- 在提交后的阶段,在结构生成方面取得了54%的成功率,在结构评级方面达到89%.
- 证明了该协议对含有柔性单体的晶体的有效性.
- 突出了基于符合性方法与刚性单体CSP的潜力.
结论:
- 本文所介绍的基于符合规范的CSP协议,使用ab initio力场,建议用于具有灵活单体的晶体.
- 该协议依赖量子力学的第一原则,使得定制的力场能够用于分子动力学模拟.
- 需要对经验性分子内力场进行进一步的开发,这些力场与初始数据重新参数化,以获得最佳的CSP性能.
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