无入侵者累积-截断驱动的相似性重规范化组第二阶段的多引用扰动理论
Shuhang Li1, Jonathon P Misiewicz1, Francesco A Evangelista1
1Department of Chemistry and Cherry Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA.
The Journal of chemical physics
|September 15, 2023
概括
本研究探讨了通过切断密度累积物来降低电子结构计算的计算成本. 结果显示显著的记忆减少,对多引用扰乱理论的准确性影响最小.
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:
- 准确的多参考电子结构计算对于潜在能量表面至关重要.
- 高的计算和存储成本,特别是更大的活跃空间,限制了常规使用.
- 这些成本源于三个和更高的体密度矩阵或累积物.
研究的目的:
- 调查累积截断方案对驱动相似性的准确性的影响,重新规范化小组二次多引用扰乱理论.
- 为了评估不同级别的三体减少密度的累积切断.
主要方法:
- 检查了四个不同级别的三体减少密度的累积切断.
- 应用了这些方法来计算CH2的单元-三元差距.
- 评估了N2的潜在能量曲线 (XΣg+1和AΣu+3状态).
- 计算的单元-三元分离对于橄烯.
主要成果:
- 累积切断引入了最小的相对和绝对误差,通常低于0.5 kcal mol-1.
- 记忆需求从O(NA^6) 减少到O(NA^5),其中NA是活跃轨道的数量.
- 为了避免入侵国家问题,不需要额外的规范化.
结论:
- 累积切断是减少多引用扰乱理论中的计算成本的有效策略.
- 这种方法保持了高精度,同时显著降低了内存需求.
- 该方法强大,不需要额外的稳定技术.
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