论文标题
使用四点相关函数揭示液体的三维结构
Revealing the three-dimensional structure of liquids using four-point correlation functions
论文作者
论文摘要
液体，凝胶，玻璃或颗粒状材料等无序系统不仅在日常生活和工业应用中无处不在，而且对于细胞的机械稳定性或生物中化学和生物学剂的运输也至关重要。尽管这些系统很重要，但它们的显微镜结构仅在基本水平上才能理解，因此与气体和晶体的情况形成鲜明对比。由于散射实验和分析计算通常仅提供球形平均的结构信息，因此无序系统的三维（3D）结构基本上是未知的。在这里，我们介绍了一种简单的方法，允许探测此类系统的3D结构。使用计算机模拟，我们发现硬球状液体在中间和大尺度上具有带有二十面体和十二面体对称性的交替层的复杂结构顺序，而二氧化硅等开放网络液体具有与四面体对称性的结构秩序。这些结果表明液体具有高度不平凡的3D结构，并且该结构信息在非标准相关函数中编码。
Disordered systems like liquids, gels, glasses, or granular materials are not only ubiquitous in daily life and in industrial applications but they are also crucial for the mechanical stability of cells or the transport of chemical and biological agents in living organisms. Despite the importance of these systems, their microscopic structure is understood only on a rudimentary level, thus in stark contrast to the case of gases and crystals. Since scattering experiments and analytical calculations usually give only structural information that is spherically averaged, the three dimensional (3D) structure of disordered systems is basically unknown. Here we introduce a simple method that allows to probe the 3D structure of such systems. Using computer simulations we find that hard-sphere-like liquids have on intermediate and large scales an intricate structural order given by alternating layers with icosahedral and dodecahedral symmetries, while open network liquids like silica have a structural order with tetrahedral symmetry. These results show that liquids have a highly non-trivial 3D structure and that this structural information is encoded in non-standard correlation functions.
