A structural analysis of the vitreous silica surface via a molecular dynamics computer simulation
A structural analysis of the vitreous silica surface via a molecular dynamics computer simulation
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通过分子动力学计算机模拟对二氧化硅玻璃表面进行结构分析
DOI：
10.1063/1.452054
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发表时间：
1987
影响因子：
4.4
通讯作者：
S. Garofalini
中科院分区：
文献类型：
--
作者：
S. Levine;S. Garofalini
采用分子动力学计算机模拟方法对纯二氧化硅玻璃表面进行了研究。这里使用的势是那些以前建立的模型块状二氧化硅的势，并已扩展到研究完全真空中的表面弛豫。使用不同的启动配置、系统大小和冷却程序制作了大量的表面。在“断裂”之后，许多断裂的键随着表面区域净力的变化而重新排列。在重建之后，模拟显示了实验观察到的预期的一般特征，例如最外表面的氧原子普遍存在，非桥氧原子，以及应变的硅氧烷键。三重硅分子(类似于e‘中心)最初存在于断裂的表面，但大多数情况下在重建后以四面体的形式结合到网络中。在重建过程中产生的其他缺陷是五个配位的硅片，更重要的是，共享四面体的边缘，形成了最大的缺陷。
Molecular dynamics computer simulations were used to study surfaces of pure silica glass. The potentials used here were those previously established to model bulk silica and have been extended to study surface relaxation in a perfect vacuum. A large number of surfaces were made using different starting configurations; system sizes, and cooling procedures. Following ‘‘fracture,’’ many broken bonds rearranged in response to the changes in the net forces in the surface region. After this reconstruction, the simulations showed the expected general features observed experimentally, such as a prevalence of oxygen atoms at the outermost surface, nonbridging oxygens, and strained siloxane bonds. Threefold silicons (similar to e’ centers) were initially present in the ‘‘fractured’’ surfaces but most often were incorporated into the network tetrahedrally after reconstruction. Other defects produced during the reconstruction were five coordinated silicons and more importantly, edge sharing tetrahedra, forming the st...