自相一致的化学压力分析:通过空间和能量的代分区来解决原子包装效应
Kyana M Sanders1, Jonathan S Van Buskirk1, Katerina P Hilleke1
1Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States.
Journal of chemical theory and computation
|June 21, 2023
概括
自相一致的DFT-化学压力 (sc-DFT-CP) 方法解决了密度函数理论计算中的参数化问题. 这种方法通过分析原子包装和尺寸效应,准确地预测金属间化合物的结构现象.
科学领域:
- 固态化学和物理 固态化学和物理
- 计算材料科学 计算材料科学
- 理论化学是一种理论化学.
背景情况:
- 平面波密度函数理论 (DFT) 方法提供了对固态结构的洞察力,但与经验化学概念缺乏直接相关性.
- DFT-化学压力 (CP) 方法将结构现象与原子大小和包装联系起来,但受到可调节参数的限制.
- 现有的方法很难解释复杂的相互生长系统中的结构趋势,例如CaCu5型/MgCu2型结构.
研究的目的:
- 引入自我一致的DFT-化学压力 (sc-DFT-CP) 分析,这与传统的CP方法相比是一个进步.
- 解决和解决先前的DFT-CP方法中固有的参数化限制.
- 证明sc-DFT-CP方法在理解金属间化合物中的原子包装和结构现象方面的实用性.
主要方法:
- 开发了代处理来分配离子性和分区DFT总能量项 (EEwald + Eα) 到同质和局部的组件.
- 通过修改的希尔什菲尔德收费方案,实现了输入和输出收费之间的自我一致性.
- 通过调整能量分割,在原子区域内和原子间相互作用中平衡的净原子压力.
主要成果:
- 通过sc-DFT-CP方法成功地解决了CaCu5类型/MgCu2类型相互生长结构中观察到的非物理趋势.
- 验证了sc-DFT-CP方法在金属间活性数据库中的数百种化合物的性能.
- 在相互生长系列中追溯结构趋势到域厚度的变化和界面格子不匹配.
结论:
- sc-DFT-CP方法有效地克服了参数化挑战,为固态结构提供了改进的预测能力.
- 这种方法提供了一个强大的理论工具,用于研究各种金属间化学物质的原子包装效应.
- 该研究证明了该方法在解释复杂的结构行为和指导材料设计方面的力量.
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