扩散量子蒙特卡洛方法在范德瓦尔斯系统与单个斯莱特-贾斯托试验波函数解离曲线上的准确性
Zhiru Huang1, Xiaojun Zhou2, Fan Wang1
1Institute of Atomic and Molecular Physics, Key Laboratory of High Energy Density Physics and Technology, Ministry of Education, Sichuan University, Chengdu, 610065, People's Republic of China. wangf44@gmail.com.
Physical chemistry chemical physics : PCCP
|February 17, 2025
概括
准确计算范德瓦尔斯 (vdW) 相互作用至关重要. 扩散量子蒙特卡洛 (DMC) 方法准确地计算了吸引力和排斥力非平衡距离的vdW电位,性能优于MP2和CCSD方法.
科学领域:
- 量子化学是一种量子化学.
- 计算物理学的计算物理.
- 分子相互作用分子相互作用.
背景情况:
- 非共价相互作用,特别是范德瓦尔斯 (vdW) 力,在化学,物理学和生命科学中是基本的.
- 准确计算VDW电位对于模拟VDW系统中的离散曲线至关重要.
- 扩散量子蒙特卡洛 (DMC) 方法已被确立用于在平衡状态下准确的vdW计算,但其在非平衡距离上的性能仍然未被探索.
研究的目的:
- 评估DMC方法在非平衡距离上计算vdW相互作用能量的准确性.
- 将DMC的性能与MP2和CCSD等传统方法进行比较,以吸引和排斥VDW潜力.
- 评估DMC内部特定近似 (DLA,T-moves) 对准确性的影响.
主要方法:
- 计算了使用DMC,MP2和CCSD的十个VDW系统的解离曲线.
- 在DMC中使用单个Slater-Jastrow试验波函数.
- 使用Dyall的局部近似 (DLA) 进行非局部伪潜值,并探索T-moves.
主要成果:
- MP2和CCSD方法准确地描述了VDW潜力的吸引力部分,但在排斥区域显示了显著的错误.
- 使用Slater-Jastrow波函数和DLA近似的DMC,实现了对吸引力和排斥力VDW电位的高精度.
- 仔细优化Jastrow因子使得可靠的DMC结果,即使在T移动.
结论:
- 与MP2和CCSD相比,使用DLA近似的DMC在非平衡距离上的vdW相互作用能量具有更高的准确性.
- 该DMC方法,特别是优化Jastrow因子,是一个能够准确计算vdW相互作用在广泛的原子间分离的工具.
- 这项研究证实了DMC在以VDW交互为主导的系统的可靠建模方面的潜力.
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