里曼的信任区域方法,以最小化局部化分子轨道的第四个中心时刻
Aliakbar Sepehri1, Run R Li2, Mark R Hoffmann1
1Chemistry Department, University of North Dakota, Grand Forks, North Dakota 58202-9024, United States.
The journal of physical chemistry. A
|June 7, 2023
概括
生成局部化的虚拟分子轨道 (MO) 是一个挑战. 这项研究引入了一种新的里曼纳信任区域算法,以有效计算这些MO,改进化学键洞察力和量子计算.
科学领域:
- 量子化学 是一个量子化学.
- 计算化学计算化学
- 理论化学 理论化学
背景情况:
- 局部化分子轨道 (MO) 对于理解化学键和增强超出平均场近似的量子相关处理至关重要.
- 虽然被占用的MO很容易被本地化,但生成正常的本地化虚拟MO带来了重大的计算挑战.
- 在多引用配置交互 (MRCISD) 和扰动理论中,对于高效的群理论方法,正规的MO是必不可少的.
研究的目的:
- 开发一种强大而高效的计算方法,用于生成非正常的本地化虚拟分子轨道.
- 为了克服标准优化算法的局限性,使用第四时刻成本函数来定位虚拟和部分占用MO.
- 提供一种方法,提高分子电子结构计算的定性理解和定量准确性.
主要方法:
- 第四个时刻的权力采用成本函数.
- 将信任区域算法应用于正规的里曼的多重体,并结合了近似的回收.
- 将里曼的信任区域外部代与截断的相结合梯度内部循环相结合,以避免计算上昂贵的线性方程或自值解决方案.
主要成果:
- 成功生成了非正常的本地化虚拟MO,克服了标准方法中常见的负赫西安固有值的问题.
- 证明了该算法的有效性在H10等模型系统和化学相关的分子,如环丁 (c-C4H4) 和propargyl基 (C3H3) 上.
- 在多配置自一致场 (MCSCF) 理论中验证了占用,虚拟和活跃空间轨道的方法.
结论:
- 开发的里曼信任区域算法为定位虚拟分子轨道提供了有效的解决方案.
- 这种方法提高了局部MO在先进的量子化学计算和化学键分析中的实用性.
- 该算法的效率和在不同的轨道空间中的适用性为计算化学研究提供了显著的优势.
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