来自组合的粒子-孔和粒子-粒子附带连接与随机相近似的多参数动态关联能量
Aleksandra Tucholska1, Katarzyna Pernal2
1J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Prague 8, Prague 18223, Czech Republic.
我们开发了一种新的附加电流连接 (AC) 框架,用于计算多参考系统中的电子相关能量. 结合 ffAC0 方法为各种化学挑战提供了高精度和高效率.
科学领域:
- 量子化学 是一个量子化学.
- 计算化学的计算化学
- 理论化学 理论化学
背景情况:
- 精确计算电子相关能量对于多参考系统至关重要.
- 现有的附带连接 (AC) 形式主义在捕捉相关性效应方面存在局限性.
- 粒子-孔 (ph) 和粒子-粒子 (pp) 表示为相关性提供了不同的视角.
研究的目的:
- 为了开发一个正式的正确的增离子连接 (AC) 框架,用于多参考相关性能量.
- 导出和实现粒子-粒子 (pp) AC形式主义.
- 提出和测试一个组合的粒子洞和粒子粒子 (ph-pp) AC方法 (ffAC).
主要方法:
- 使用费米子运算符代数推导ppAC形式主义.
- 基于扩展随机阶段近似的实现.
- 通过合并ph和pp相关幅度来开发联合的ffAC方法.
主要成果:
- 第二级多参数pp相关性能量自然在ppAC框架内出现.
- 结合的ffAC方法成功地结合了ph和pp的相关性贡献,避免了双重计数.
- 线性 ffAC0 方法在各种具有挑战性的化学系统中表现出卓越的准确性,匹配或超过 NEVPT2.
- 在计算上,ffAC0比NEVPT2更高效,只需要一个和两个电子的低密度矩阵.
结论:
- 衍生出来的ppAC形式主义为多引用相关性提供了一个强大的框架.
- 结合 ffAC 方法为电子相关性提供了一个平衡而准确的方法.
- ffAC0方法在计算效率和准确性方面取得了显著的进步,用于多参考相关性能量计算.
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