波动电荷对分子极化性和分散系数的影响
YingXing Cheng1, Toon Verstraelen1
1Center for Molecular Modeling (CMM), Ghent University, Technologiepark-Zwijnaarde 46, B-9052 Ghent, Belgium.
The Journal of chemical physics
|September 6, 2023
概括
电荷流显著影响分子动态响应特性,如极化性和分散系数,特别是在具有极化键的较大分子中. 显式建模电荷流可以增强分子模拟和力场.
科学领域:
- 计算化学是一种计算化学.
- 理论化学是一种理论化学.
- 量子化学是一种量子化学.
背景情况:
- 动态线性响应特性对于理解分子相互作用至关重要.
- 之前的研究强调了电费波动的重要性,但缺乏定量描述.
- ACKS2ω模型为计算频率依赖的分子极化性提供了一个框架.
研究的目的:
- 评估波动电荷对分子动态线性响应特性的影响.
- 开发新的描述器来量化对响应属性的电荷-流量贡献.
- 为了研究分子几何学和极化键对电荷流的影响.
主要方法:
- 利用了以频率为依赖的原子凝聚的Kohn-Sham密度函数理论,近似为二次 (ACKS2ω) 模型.
- 定义了基于回双极极化能力的两个新描述符,以量化电荷流贡献.
- 计算了TS42数据库中分子的分子极化度和C6分散系数.
主要成果:
- 电荷流贡献显著影响双极极化能力和C6分散系数,特别是对于较大的分子和具有极化键的分子.
- 开发的描述器成功量化了电荷流量贡献,显示了两个不同的计算方法之间的兼容性.
- 发现电荷流质量地复制着极化性异构性,并有助于异构性C6系数.
- 波动电荷的影响仅在非常小的分子中是可以忽略不计的.
结论:
- 波动电荷在分子的动态线性响应特性中起着关键作用,特别是具有极化键的较大分子.
- 电荷流动效应是非局部的,受到化学键和几何学的影响,不能仅仅归因于单个原子性质.
- 建议在极化力场和分散模型中明确建模电荷流,以提高分子模拟的准确性.
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