非共价相互作用能量与无相辅助场 量子蒙特卡洛
Devesh Awasthi1, Leon Otis1, Emily Huang2
1Department of Chemistry, Rice University, Houston, Texas 77005-1892, United States.
Journal of chemical theory and computation
|December 16, 2025
概括
我们评估了无相辅助场量子蒙特卡洛 (ph-AFQMC) 模型来描述非共价相互作用. 这种方法的准确性高于合集群单双 (CCSD) 和莫勒-普莱塞特扰动理论 (MP2),使其对更大的分子研究具有前景.
科学领域:
- 量子化学是一种量子化学.
- 计算化学是一种计算化学.
- 材料科学是一种材料科学.
背景情况:
- 非共价相互作用在各种化学和生物系统中至关重要.
- 准确地描述这些相互作用与计算模型仍然是一个挑战.
- 大致的电子结构方法经常与相关性效应和系统大小作斗争.
研究的目的:
- 为了评估无相辅助场量子蒙特卡罗 (ph-AFQMC) 方法对非共价相互作用的性能.
- 为了将ph-AFQMC准确度与高级计算参考进行比较.
- 探索降低ph-AFQMC计算的计算成本的策略.
主要方法:
- 使用受限制的Hartree-Fock (RHF) 试波函数评估最简单的无相辅助场量子蒙特卡罗 (ph-AFQMC) 模型.
- 对结,静电和分散 (S66,A24,S22,X31) 的标准数据集进行测试.
- 使用CCSDTQ参考能量和分支相关的采样方案进行水二次数计算.
主要成果:
- ph-AFQMC-RHF在非共价相互作用方面显示的准确性始终优于单元和双元 (CCSD) 的合集群,并且明显优于莫勒-普莱塞特扰动理论 (MP2).
- 观察到非共价相互作用能量的ph-AFQMC-RHF计算中的错误取消.
- 一个分支相关的抽样方案被证明可以降低计算成本.
结论:
- ph-AFQMC方法,特别是具有RHF试验函数的方法,为研究非共价相互作用提供了一个有希望和准确的方法.
- 观察到的错误取消和成本降低策略提高了ph-AFQMC对于较大的分子系统的可行性.
- 这项工作为ph-AFQMC在化学和材料科学领域的更广泛应用铺平了道路.
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