标题： 通过反向蒙特卡罗模拟从X射线散射实验数据中估算键长和热膨胀系数 显示英文标题

标题： Estimates of bond length and thermal expansion coefficients from x-ray scattering experimental data using reverse Monte Carlo simulations

摘要： 之前讨论的异常行为（即负值）的热膨胀系数是通过最近邻距离（键长）分布来研究的。 键长分布是通过对从X射线散射数据的反向蒙特卡罗模拟和分子动力学模拟获得的原子结构进行维诺图划分分析得到的。 当使用稳健的集中趋势度量（均值或中位数）时，从温度依赖的键长得到的正热膨胀与从体积随温度变化的直接测量结果具有相同的量级。 当跟踪在对分布函数的高阶峰中获得的较大邻居距离时，情况也是如此。 这对最近提出的金属液体的脆弱性嵌入在这些高阶峰中的说法提出了质疑。 这也表明之前报道的键长异常收缩是由于跟踪了众数，而众数没有考虑分布的偏度。 显示英文摘要

摘要： The previously discussed anomalous behavior (i.e. negative) of the thermal expansion coefficient obtained from the pair correlation function is examined in the context of the nearest-neighbor distance (bond length) distribution. The bond length distribution is obtained from a Voronoi tessellation analysis of the atomic structures obtained from both reverse Monte Carlo simulations of x-ray scattering data and molecular dynamics simulations. When a robust measure of central tendency (mean or median) is used a positive thermal expansion is obtained from the temperature-dependent bond length that has the same magnitude as that obtained from direct measurements of the volume as a function of temperature. The same is true when larger neighbor distances, as obtained in higher order peaks in the pair distribution function are tracked. This calls into question the recent claim that fragility of metallic liquids is embedded in these higher order peaks. It also shows that the previously reported anomalous contraction of the bond length arise from tracking the mode, which does not account for the skewness of the distribution.