Du XiangPo, Tse John S
State Key Laboratory for Superhard Materials, Jilin University , Changchun 130012, P. R. China.
Department of Physics and Engineering Physics, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5E2, Canada.
J Phys Chem B. 2017 Nov 30;121(47):10726-10732. doi: 10.1021/acs.jpcb.7b09357. Epub 2017 Nov 15.
The recently proposed relationship between the oxygen volume fraction and topological ordering in solid and liquid oxide glasses at high pressure is examined with Bader's atoms-in-molecules (AIM) theory using glass structures generated from first principles molecular dynamics calculations. It is shown that the atomic (O/Si and O/Ge) volume ratio derived from AIM theory is not constant with pressure. This finding is due to the continuous change in the electron topology under compression. Unlike crystalline solids, there is no distinctive transition pressure for Si-O and Ge-O coordination in a glass; instead, the changes are gradual and continuous over a broad pressure range. Therefore, relating a unique Si-O or Ge-O coordination number to the properties of the glass at a given pressure is difficult.
利用第一性原理分子动力学计算生成的玻璃结构，采用巴德分子中的原子（AIM）理论，研究了最近提出的高压下固体和液体氧化物玻璃中氧体积分数与拓扑有序性之间的关系。结果表明，由AIM理论得出的原子（O/Si和O/Ge）体积比随压力并非恒定不变。这一发现是由于压缩过程中电子拓扑结构的持续变化所致。与晶体固体不同，玻璃中Si-O和Ge-O配位不存在明显的转变压力；相反，在很宽的压力范围内，变化是渐进且连续的。因此，在给定压力下将独特的Si-O或Ge-O配位数与玻璃的性质联系起来是困难的。
