距离隔离的混合功能,用于准确预测扩展系统的频段间隙
Jing Yang1, Stefano Falletta1, Alfredo Pasquarello1
1Chaire de Simulation à l'Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, CH-1015 Switzerland.
概括
距离分离的混合功能器准确地预测半导体和绝缘体中的带间隙. 优化短距离的福克交换和选长度大大减少了预测错误,提供了一种通用方法.
科学领域:
- 材料科学 材料科学 材料科学
- 计算化学计算化学
- 固态物理 固态物理
背景情况:
- 对材料带间隙的准确预测对于设计新的半导体和绝缘体至关重要.
- 像PBE0和HSE06这样的标准混合函数在描述电子属性方面存在局限性,特别是频段间隙.
- 距离分离的混合功能通过不同处理短距离和远距离电子交换相互作用来提供潜在的改进.
研究的目的:
- 系统地评估范围隔离混合函数的准确性,用于在广泛的材料中预测带隙.
- 为了比较范围分离的混合功能与标准的全球混合功能之间的性能.
- 开发一种优化的方法来选择范围分离的混合函数中的参数,以尽量减少预测错误.
主要方法:
- 系统评估各种范围分离的混合功能.
- 结果与已确定的功能结果进行比较 (PBE0,HSE06).
- 分析短距离福克交换分数和选长度对准确度的影响.
- 为逆选参数开发一个通用表达式.
主要成果:
- 距离分离的混合功能器,准确模拟远距离介电选,比标准的混合功能器显著改进.
- 调整短距离的福克交换分数和选长度进一步提高了预测的准确性.
- 为逆选参数提出的通用表达式为带隙预测产生0.15 eV的平均绝对误差.
结论:
- 距离分离的混合功能对于半导体和绝缘体中准确的带隙预测非常有效.
- 优化参数选择是最大限度地提高这些函数的性能的关键.
- 开发的通用表达式为参数选择提供了可靠的方法,推进了计算材料设计.
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