Determination of accurate, mean bond lengths from radial distribution functions
Determination of accurate, mean bond lengths from radial distribution functions
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DOI：
10.1063/1.4973804
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发表时间：
2017-01-14
影响因子：
4.4
通讯作者：
Mueser, Martin H.
中科院分区：
文献类型：
--
作者：
Sukhomlinov, Sergey V.;Mueser, Martin H.
从径向分布函数g(r)的第一个峰的位置可以估计出中心原子与其最近邻居之间的平均键长d。然而，正如我们在这里所展示的，这种估计不允许人们推断温度引起的d变化。相反，偏度必须包含在分析中，例如，可以通过偏正态分布（SND）来实现。使用SND拟合到第一个峰值给出的键长与晶体中最近邻分布函数的直接测量结果以及基于Voronoi-tessellation的液体中最近邻检测结果非常吻合。对于氩、铜和大块金属玻璃（BMG）成形合金zr60cu30al10，随着温度的升高，g(r)的第一个峰值的位置可能会变小。我们发现，在所有情况下，我们对d的改进估计都随着温度的升高而系统地增加。因此，最近关于简单金属或bmg形成液体中温度诱导键收缩的结论可能是由于忽略了偏度效应而产生的。AIP出版社出版。
The mean bond length d between a central atom and its nearest neighbors can be estimated from the position of the first peak in the radial distribution function g(r). However, as we demonstrate here, this estimate does not allow one to deduce temperature-induced changes in d. Instead, skewness has to be included into the analysis, which can be achieved, for example, via the skewnormal distribution (SND). Fits to the first peak using the SND give bond length in good agreement with direct measurements of nearest-neighbor distribution functions in crystals as well as with a Voronoi-tessellation based detection of nearest-neighbors in liquids. While the location of the first peak in g(r) may shift to smaller values with increasing temperature for three studied liquids-argon, copper, and the bulk-metallicglass (BMG) forming alloy Zr60Cu30Al10-we find our improved estimates of d to systematically increase with temperature in all cases. Recent conclusions on temperature-induced bond contractions in simple metallic or BMG-forming liquids may therefore have arisen from the neglect of skewness effects. Published by AIP Publishing.