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arXiv 2411.08065physics.chem-phcond-mat.mtrl-scicond-mat.stat-mech
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h-CMD:一种用于振动光谱模拟的高效混合快速质心与准质心分子动力学方法

h-CMD: An efficient hybrid fast centroid and quasi-centroid molecular dynamics method for the simulation of vibrational spectra

Dil K. Limbu, Nathan London, Md Omar Faruque, Mohammad R. Momeni

AI总结:

本文提出 h-CMD 方法,将 f-QCMD 与 f-CMD 混合用于异质界面振动光谱模拟,在 ZIF-90 限域 D2O 体系中验证其可纠正 CMD 曲率问题和 T-RPMD 光谱过度展宽问题,并与实验高度吻合。

摘要:

为异质凝聚相和界面中的振动光谱原子级模拟开发高效的路径积分(PI)方法长期以来一直是一项具有挑战性的任务。在此,我们提出了 h-CMD 方法,即混合质心分子动力学(hybrid centroid molecular dynamics)的缩写,该方法将最近提出的快速准质心分子动力学(f-QCMD)方法与快速质心分子动力学(f-CMD)相结合。在该方案中,被认为更严重地受到 CMD 曲率问题影响的分子(例如水)采用 f-QCMD 处理,而其余部分(例如固体表面)则采用 f-CMD 处理。为了测试这一新提出方案的准确性,我们使用 h-CMD 模拟了限制在典型 ZIF-90 框架中的界面 D2O 的红外光谱,并与多种其他 PI 方法进行了比较,包括恒温环聚合物分子动力学(T-RPMD)、部分绝热 CMD 以及作为参考的 f-CMD 和实验。同时还与完全忽略核量子效应的经典 MD 进行了比较。我们在 250-600 K 不同温度下的详细比较表明,h-CMD 产生的 O-D 伸缩振动峰与实验高度吻合,纠正了已知的曲率问题以及 CMD 伸缩峰的红移问题。h-CMD 还纠正了 T-RPMD 已知的与过度人为阻尼和展宽光谱相关的问题,该问题导致界面受限水的特征双峰结构缺失,使其不适用于这些体系。新的 h-CMD 方法将 f-QCMD 的适用范围扩展到异质凝聚相和界面,在这些体系中为整个系统定义曲线坐标是不可行的。

英文摘要:

Developing efficient path integral (PI) methods for atomistic simulations of vibrational spectra in heterogeneous condensed phases and interfaces has long been a challenging task. Here, we present the h-CMD method, short for hybrid centroid molecular dynamics, that combines the recently introduced fast quasi-CMD (f-QCMD) method with fast CMD (f-CMD). In this scheme, molecules that are believed to suffer more seriously from the curvature problem of CMD, e.g., water, are treated with f-QCMD, while the rest, e.g., solid surfaces, are treated with f-CMD. To test the accuracy of the newly introduced scheme, the infrared spectra of the interfacial D2O confined in the archetypal ZIF-90 framework are simulated using h-CMD compared to a variety of other PI methods, including thermostatted ring-polymer molecular dynamics (T-RPMD) and partially adiabatic CMD as well as f-CMD and experiment as reference. Comparisons are also made to classical MD, where nuclear quantum effects are neglected entirely. Our detailed comparisons at different temperatures of 250-600 K show that h-CMD produces O-D stretches that are in close agreement with the experiment, correcting the known curvature problem and red-shifting of the stretch peaks of CMD. h-CMD also corrects the known issues associated with too artificially dampened and broadened spectra of T-RPMD, which leads to missing the characteristic doublet feature of the interfacial confined water, rendering it unsuitable for these systems. The new h-CMD method broadens the applicability of f-QCMD to heterogeneous condensed phases and interfaces, where defining curvilinear coordinates for the entire system is not feasible.

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