在截断的运动方程合集群方法中违反了N-表示性
Stephen H Yuwono1, A Eugene DePrince1
1Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, USA.
The Journal of chemical physics
|August 7, 2023
概括
运动方程合集群计算可以产生非物理的一个电子的低密度矩阵 (1RDM). 这些非物理的1RDM,即使来自有效状态,也挑战了量子化学中时间依赖模拟的解释.
科学领域:
- 量子化学 是一个量子化学.
- 计算物理 计算物理
- 理论化学 理论化学
背景情况:
- 一个电子减少密度矩阵 (1RDMs) 对于描述量子力学中的电子状态至关重要.
- 一个1RDM的N-表示性确保它与有效的N-电子量子状态相对应.
- 运动方程合集群 (EOM-CC) 方法被广泛用于电子结构计算.
研究的目的:
- 分析1RDMs的N-表示性,通过单双激发 (EOM-CCSD) 的运动方程合集群计算得到的.
- 为了确定EOM-CCSD 1RDM可能与物理N电子状态不相应的条件.
- 调查对时间依赖的EOM-CC模拟的影响.
主要方法:
- 分析来自EOM-CCSD静态状态的一个电子减少密度矩阵 (1RDMs).
- 使用集合状态和纯状态 (通用保利约束) 条件评估N-可表示性.
- 在外部场下的时间依赖的EOM-CC模拟中检查1RDMs.
主要成果:
- 识别了EOM-CCSD静态状态,其中1RDMs违反了N-可表示性条件 (整体和纯态).
- 证明这些非物理的1RDM不代表任何有效的N电子量子状态.
- 在EOM-CC模拟中观察到对时间依赖状态的集合状态N-表示性的违反.
结论:
- EOM-CCSD计算可以产生物理无法实现的1RDM.
- 非物理的1RDM甚至可以从静止状态和时间依赖的进化过程中产生.
- 这些发现突出了解释时间依赖的EOM-CCSD模拟结果的潜在挑战.
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