对于高能分子晶体,晶体结构预测有多准确?
Xavier Bidault1, Santanu Chaudhuri1,2
1Department of Civil, Materials and Environmental Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA.
Molecules (Basel, Switzerland)
|June 10, 2023
概括
使用进化算法 (EA) 和分散校正密度函数理论 (DFT-D) 的晶体结构预测 (CSP) 成功预测了具有挑战性的高能分子晶体的实验结构. 这种方法从中性起点准确地模拟分子包装和构造.
科学领域:
- 计算化学计算化学
- 材料科学 材料科学 材料科学
- 晶体学 晶体学是指结晶学.
背景情况:
- 分子晶体表现出复杂的,浅的潜在能量景观,具有众多的局部最小值.
- 准确预测分子包装和构造是至关重要的,特别是对于多态生物.
- 对于可靠的晶体结构预测 (CSP),通常需要高精度的初始方法.
研究的目的:
- 为了评估进化算法 (EA) 与分散校正密度函数理论 (DFT-D) 对CSP的有效性.
- 评估对具有挑战性的高能分子晶体 (HMX,RDX,CL-20,FOX-7) 的预测能力.
- 为了确定实验结构是否可以从中性分子构造开始预测.
主要方法:
- 使用进化算法 (EA) 进行晶体结构预测.
- 使用分散校正密度函数理论 (DFT-D) 进行能量计算.
- 使用完全灵活的分子和可变单元细胞进行模拟,从中性构造开始.
主要成果:
- 在20代内,EA-DFT-D方法成功预测了HMX,RDX,CL-20和FOX-7的实验晶体结构.
- 从中性形状开始,而不是实验性形状,对于现实的CSP.证明有效.
- 确定某些系统可能需要在空间组之间进行广泛的尝试或用于结构歧视的更高精度计算.
结论:
- EA-DFT-D方法是预测高能分子材料晶体结构的强大工具.
- 这种方法证明了CSP的可行性,即使初始分子构造在实验中还未知.
- 在未来的研究中,建议采用混合xTB/DFT-D方法,以提高大型系统和共晶体的计算效率.
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