Typeset Using Revt E X
Typeset Using Revt E X
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发表时间：
1992
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通讯作者：
Jarek Luberek;Göran Wendin
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作者：
Jarek Luberek;Göran Wendin
四硅酸钠玻璃Na 2 Si 4 O 9的结构和电子性质的经典和从头算分子动力学模拟。摘要采用经典分子动力学方法和Car-Parrinello方法研究了四硅酸钠玻璃的结构和电子性质。玻璃样品的制备采用最近在石英玻璃研究中采用的方法[M. Benoit等人，Euro. J. B 13，631（2000）]。首先，我们用经典分子动力学方法生成了一个NS 4玻璃，然后将其作为第一性原理分子动力学模拟的初始构型。在从头算分子动力学模拟中，电子结构在广义梯度近似下的Kohn-Sham密度泛函理论的框架内使用B-LYP泛函计算。在所考虑的轨迹期间，Car-Parrinello动力学非常稳定，并且一旦它被打开，就会发生一些显著的结构变化。从头计算描述提高了与实验数据的结构特征的比较，特别是关于Si-O和Na-O键长。从电子的角度来看，我们发现，在二氧化硅网络中的氧化钠的引入降低了带隙，并导致网络原子的电荷的高度非局域化的效果。
Structural and electronic properties of the sodium tetrasilicate glass Na 2 Si 4 O 9 from classical and ab initio molecular-dynamics simulations. Abstract The structure and the electronic properties of a sodium tetrasilicate (Na 2 Si 4 O 9) glass were studied by combined Car-Parrinello and classical molecular-dynamics simulations. The glass sample was prepared using a method recently employed in a study of a silica glass [M. Benoit et al, Euro. Phys. J. B 13, 631 (2000)]. First we generated a NS4 glass by classical molecular-dynamics and then we took it as the initial configuration of a first-principles molecular-dynamics simulation. In the ab initio molecular-dynamics simulation, the electronic structure was computed in the framework of the Kohn-Sham density functional theory within the generalized gradient approximation using a B-LYP functional. The Car-Parrinello dynamics is remarkably stable during the considered trajectory and, as soon as it is switched on, some significant structural changes occur. The ab initio description improves the comparison of the structural characteristics with experimental data, in particular concerning the Si-O and Na-O bond lengths. From an electronic point of view, we find that the introduction of the sodium oxide in the silica network lowers the band gap and leads to a highly non-localized effect on the charges of the network atoms.