Molecular dyunamics simulation of extreme thermal and mechanical conditions

极端热力和机械条件的分子动力学模拟

• 批准号: 261550-2007
• 负责人: Mueser, Martin
• 金额: $ 2.8万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=364901
• 关键词: Molecular; dyunamics; simulation; extreme; thermal

The goal outlined in this proposal is two-fold: First, we would like to increase our ability to model materials with atomistic simulations, in particular with molecular dynamics. For this purpose, we would like to improve our capability to predict the electrostatics of molecular systems without having to revert to first principle methods. Second, we plan to investigate the response of specific, technologically relevant materials to extreme conditions.     The molecular dynamics-based modeling of processes involving coordination changes or bond breaking and formation is strongly impeded by our inability to predict the electrostatics of molecular systems. We would like to further develop a recently suggested scheme that attempts to overcome this deficiency. The new approach combines two schemes that previously were mutually exclusive, specifically a bond-type and an atom-type description of electrostatics. Our method development will also support attempts to treat polarizability and dispersive interactions on an equal footing.     Applications of MD are anticipated for two classes of materials, specifically metal phosphates, which are used as anti-wear additives in lubricants, as well as so-called phase change materials, i.e., alloys consisting of germanium, antimony, and tellurium, which are used in optical storage media. The combining element of both classes of materials is that their functionality appears to be intimately linked to coordination changes, e.g., zinc changes its coordination in zincphosphates under pressure (thereby forming networked anti-wear films) and germanium changes its coordination under laser radiation (thereby switching the alloy between being conducting and being insulating). To be better able to tailor these materials to our needs, we plan to obtain a more thorough understanding of their phase diagrams, in particular as a function of their detailed chemical composition. We hope to provide guidelines for the design of higher density optical storage media and new, environmentally friendly anti-wear additives.

该提案中概述的目标是双重的：首先，我们希望提高我们用原子模拟，特别是分子动力学模拟材料的能力。为了这个目的，我们想提高我们的能力来预测静电的分子系统，而不必返回到第一原理方法。其次，我们计划研究特定的、技术相关的材料对极端条件的反应。 由于我们无法预测分子系统的静电，因此，涉及配位变化或键断裂和形成的过程的基于分子动力学的建模受到强烈阻碍。我们想进一步发展最近提出的一个计划，试图克服这一缺陷。新的方法结合了两个方案，以前是相互排斥的，特别是一个键型和原子型描述的静电。我们的方法开发也将支持尝试在平等的基础上对待极化率和色散相互作用。 MD的应用预期用于两类材料，特别是用作润滑剂中的抗磨添加剂的金属磷酸盐，以及所谓的相变材料，即，由锗、锑和碲组成的合金，用于光存储介质。这两类材料的结合元素是它们的功能似乎与配位变化密切相关，例如，锌在压力下改变其在磷酸锌中的配位（从而形成网状抗磨膜），锗在激光辐射下改变其配位（从而使合金在导电和绝缘之间转换）。为了更好地根据我们的需求定制这些材料，我们计划更深入地了解它们的相图，特别是它们的详细化学成分。我们希望为设计更高密度的光存储介质和新的环保抗磨添加剂提供指导。