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激发状态与对合集群双重定制的合集群理论
Moneesha Ravi1, Ajith Perera1, Young Choon Park2
1Quantum Theory Project, University of Florida, Gainesville, Florida 32611-8435, USA.
The Journal of chemical physics
|September 1, 2023
概括
双联集群双重 (pCCD) 可以改善对二基分子激发状态的计算. 这种定制的合集群方法提高了多参考系统的准确性,特别是在使用特定轨道时.
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:
- 合集群理论是描述电子相关性的强大方法.
- 定制技术可以将非动态电子相关效应纳入合集群方法中.
- 配对合集群双重 (pCCD) 已经显示出对非动态相关性问题,如债券破裂的承诺.
研究的目的:
- 调查pCCD作为一个用于激发状态的定制合集群单双 (TCCSD) 的内核的实用性.
- 评估各种类型的激发状态的TCCSD性能,包括单次和双次激发.
- 评估pCCD-kernel TCCSD的准确性,用于二基系统中的单元-三元分割.
主要方法:
- 使用pCCD作为内核的定制合集群单双 (TCCSD) 的应用.
- 探索激发状态,从单次激发到双倍激发.
- 用一般化的价值键轨道计算二基分子的单点-三点间隙.
主要成果:
- 使用pCCD内核的TCCSD与单个和双重激发状态的运动方程-CCSD相比没有任何改善.
- 在二基分子中的单基三基差距中观察到显著的改善.
- 在pCCD内核与用于多参考二基态的通用价值键轨道相结合时,它表现出了特别高的效率.
结论:
- 在TCCSD中的pCCD内核对于所有激发状态计算并不普遍有益.
- 这种方法对准确描述二极根系统的电子结构具有前景.
- 未来的工作可能会专注于改进基于pCCD的方法,以解决挑战性的多参考问题.
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