论文标题
无环的局部结构有序的环形各向异性二氧化碳和结晶硅
Ring-originated anisotropy of local structural ordering in amorphous and crystalline silicon dioxide
论文作者
论文摘要
包含化学键合原子的环是用于网络形成材料的结构排序的基本拓扑基序。量化此类较大基序以外的较大基序相关性，对于理解有序和宏观行为之间的联系至关重要。在这里，我们提出了基于环的两种定量分析方法。第一种方法通过两个几何指标量化环：圆度和粗糙度。这些指标揭示了高度对称环与二氧化硅中的晶体对称性之间的联系，而无定形二氧化硅的结构主要由扭曲的环组成。第二种方法量化了描述环周围三维原子密度的空间相关函数。不同程度的环对称性功能之间的比较分析表明，对称环有助于无定形二氧化硅的局部结构顺序。对具有不同顺序的无定形模型的另一项分析揭示了环周围局部结构排序的各向异性。这有助于建立中间订单。
Rings comprising chemically bonded atoms are essential topological motifs for the structural ordering of network-forming materials. Quantification of such larger motifs beyond short-range pair correlation is essential for understanding the linkages between the orderings and macroscopic behaviors. Here, we propose two quantitative analysis methods based on rings. The first method quantifies rings by two geometric indicators: roundness and roughness. These indicators reveal the linkages between highly symmetric rings and crystal symmetry in silica and that the structure of amorphous silica mainly consists of distorted rings. The second method quantifies a spatial correlation function that describes three-dimensional atomic densities around rings. A comparative analysis among the functions for different degrees of ring symmetries reveals that symmetric rings contribute to the local structural order in amorphous silica. Another analysis of amorphous models with different orderings reveals anisotropy of the local structural ordering around rings; this contributes to building the intermediate-range ordering.
