论文标题
使用力量！分子模拟中密度，径向分布函数和局部迁移率的方差估计器降低
Use the force! Reduced variance estimators for densities, radial distribution functions and local mobilities in molecular simulations
论文作者
论文摘要
即使局部特性的计算（例如密度或径向分布函数）仍然是分子模拟的最标准目标之一，但它仍然在很大程度上依赖于基于直方图的直方图策略。在这里，我们重点介绍了从不同的角度到估计量与常规隔板相比降低的估计量的最新发展。它们都利用作用在颗粒上的力，除了它们的位置外，并允许关注问题的非平凡部分，以减轻（或在某些情况下）随着垃圾箱尺寸的减小，直方图的灾难性行为。对于分子动力学模拟，相应的计算成本可以忽略不计，因为已经计算了力来生成配置，并且当产生后者的成本很高时，降低的变化估计器的好处甚至更大，尤其是使用irible模拟。力采样方法可能会导致不存在颗粒的区域中的密度杂散的残留非零值，但是可以使用策略来减轻该人物。我们在数量，电荷和极化密度，径向分布功能和本地运输系数上说明了这种方法，讨论了各种观点之间的联系，并提出了这种有前途的方法的未来挑战。
Even though the computation of local properties, such as densities or radial distribution functions, remains one of the most standard goals of molecular simulation, it still largely relies on straighforward histogram-based strategies. Here we highlight recent developments of alternative approaches leading, from different perspectives, to estimators with a reduced variance compared to conventional binning. They all make use of the force acting on the particles, in addition to their position, and allow to focus on the non-trivial part of the problem in order to alleviate (or even remove in some cases) the catastrophic behaviour of histograms as the bin size decreases. The corresponding computational cost is negligible for molecular dynamics simulations, since the forces are already computed to generate the configurations, and the benefit of reduced-variance estimators is even larger when the cost of generating the latter is high, in particular with ab initio simulations. The force sampling approach may result in spurious residual non-zero values of the density in regions where no particles are present, but strategies are available to mitigate this artefact. We illustrate this approach on number, charge and polarization densities, radial distribution functions and local transport coefficients, discuss the connections between the various perspectives and suggest future challenges for this promising approach.
