在二氨基离子和里德伯格激发状态中的局部和非局部电荷分布:密度函数的挑战性测试
Benedikt O Birgisson1, Marta Gałyńska1,2, Hemanadhan Myneni1
1Science Institute and Faculty of Physical Sciences, University of Iceland, 107 Reykjavík, Iceland.
The journal of physical chemistry letters
|June 4, 2025
概括
密度函数理论的计算揭示了N,N'-二甲基piperazine (DMP) 中的电子分布如何取决于福克交换和自我相互作用校正. 更强的福克交换或完全的自我相互作用校正有利于局部电子,这对于准确的激发状态和电离分子建模至关重要.
科学领域:
- 计算化学的计算化学
- 量子化学 是一个量子化学.
- 材料科学 材料科学 材料科学
背景情况:
- 精确的电子分布建模对于理解分子性质至关重要.
- 密度函数理论 (DFT) 是一个强大的工具,但它的准确性取决于功能选择.
- 在激发和电离状态下,N,N-二甲基皮佩拉 (DMP) 的行为对DFT构成了挑战.
研究的目的:
- 测试各种密度函数在描述电子定位/移位方面的性能.
- 为了研究福克交换 (FE) 权重在混合函数中的影响.
- 评估SIC在DFT计算中的自我相互作用校正 (SIC) 对DMP的有效性.
主要方法:
- 计算使用了雅各布梯子上的密度函数,包括LDA,混合体和双混合体.
- 在其3s Rydberg兴奋状态和完全电离的DMP+离子中研究了DMP.
- 在PBE0中分析了不同FE权重的影响,并将完整和缩放的SIC应用于PBE.
主要成果:
- 常见的混合函数 (例如,0.25 FE 的 PBE0) 为 DMP+ 带来了非本地化的收费.
- 具有更高FE权重 (例如,PBE0(0.50),BHLYP) 和完全SIC的功能器产生局部充电最小值.
- 对于瑞德伯格州,PBE0(0.32) 显示了局部化和非局部化的洞,而PBE 显示的只有非局部化的洞.
结论:
- 在DMP中局部与非局部电子的平衡对DFT功能参数敏感.
- 需要更高的福克交换或完整的SIC来捕获电荷定位在电离化的DMP中.
- 减少自我交互错误对于准确的DFT预测DMP的Rydberg兴奋状态至关重要.
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