玻璃形成液体其内在结构中的二十面体

采用分子动力学模拟(molecular dynamics简称MD)的方法,并利用势能曲面(potential energy landscape简称PEL)理论对玻璃形成液体进行研究.在模拟中,键角分布序参数(An)被首先应用于描述二元玻璃形成液体其内在结构(Inherent Structure简称IS)中的结构序.通过计算An,得出了一般液体和IS液体中六面体、八面体和二十面体结构随温度的变化情况.在IS液体中二十面体序所占比例明显多于一般液体.在IS液体中,六面体、八面体的结构随温度的变化不是很明显,而二十面体结构随着温度的变化呈现出一定的规律.得出了二十面体是IS的主要变化的结构.玻璃转变是一般液体接近IS的过程,同时也是二十面体增多的过程.

Study on icosahedral order in inherent structures of glass-forming liquids

The molecular dynamics simulation with potential energy landscape model was ap-plied to investigate the glass-forming liquids .In this paper , a new bond angle distribution or-der parameter （ An） was used to describe the structural order of the inherent structure （ IS） in the glass-forming liquids .The variation of hexahedron , octahedron , and icosahedral order with temperature was discussed in typical and IS liquids .As a results, hexahedron, octahed-ron , and icosahedral order with temperature changed slightly , while the changing of icosahe-dral order was much obvious .There was more icosahedron order in IS than typical liquids and the icosahedral order was the prominent packing structure of the stable IS .The glass transition was a process of typical liquids approaching IS .It was also an increasing process of icosahedron order .