Energetics and Excitations of Glass-Forming Materials

加州大学伯克利分校的大卫·钱德勒（David Chandler）获得了化学部门化学理论、模型和计算方法项目的奖励，他在非平衡统计力学领域开展了研究，特别是阐明了玻璃化转变的潜在驱动力和影响。这些是复杂系统远离平衡状态的转变，这种转变表现在结构轨迹空间中。理论技术直到最近才允许对它们进行系统分析，这些技术的结果现在被用于这项研究，以进一步探索从简单到复杂混合物系统中玻璃转变的分子起源。特别地，本研究旨在对玻璃中基本激发的能量和结构进行预测理论研究。它应该回答这些性质如何与玻璃的制备，玻璃对应力的反应以及组分的变化有关。该理论应该具有一定程度的普遍性，以揭示其他类别材料的含义，做出可以通过实验测试的预测，并具有实际的近似和由分子模拟得出的明确结果指导的见解。这项工作处于当代统计物理学的前沿。科学家们早就了解平衡理论的原理，并利用这些原理来设计有用的有序和规则的凝聚相。例子包括炼油工业中使用的规则溶液理论，以及钢铁工业中使用的奥斯特瓦尔德成核步进规则。但是，对于动力学捕获的无序固体和纳米团簇（如玻璃等材料，通过使液体物质失去平衡而出现），还没有类似的基本理解。这项研究致力于改善这一知识差距。特别是玻璃，这些材料是杂质的欢迎和长期稳定的宿主。因此，在考虑安全稳定地储存放射性废料时，玻璃是首选材料。二次有机气溶胶（soa）具有类似的或可能更重要的意义，它们通常处于玻璃态。它们的转变在大气化学中起着主导作用，影响着地球的气候和人类的健康。因此，这项研究解决了与社会重大问题有关的问题。它的深刻重要性和它的基本性质使它非常适合激励和训练学生成为科学家。

David Chandler of the University of California, Berkeley is supported by an award from the Chemical Theory, Models and Computational Methods Program in the Chemistry division to carry out research in the area of non-equilibrium statistical mechanics, specifically to elucidate the underlying driving forces and implications of glass transitions. These are transitions of complex systems driven far from equilibrium, transitions manifested in the structure trajectory space. Theoretical techniques have only recently allowed for their systematic analysis, and results from these techniques are now being used in this research to further explore the molecular origins of glass transitions in systems ranging from simple to complex mixtures. In particular, this research aims at predictive theory for the energies and structures of elementary excitations in glass. It should answer how these properties relate to the preparation of the glass, to responses of glass to stress, and to changes in components. The theory should have a degree of generality to reveal implications for other classes of materials, making predictions that can be tested by experiment, and with practical approximations and insights guided by unambiguous results derived from molecular simulation.The work is at the frontier of contemporary statistical physics. Scientists have long understood the principles of equilibrium theory and exploited these principles to design useful ordered and regular condensed phases. Examples include regular solution theory as it is used in the oil-refining industry, and the Ostwald step rule for nucleation used in the steel industry. But no similarly fundamental understanding is yet available for kinetically trapped disordered solids and nanoclusters -- materials, like glass, that emerge by driving liquid matter out of equilibrium. This research is devoted to ameliorating this gap in knowledge. Concerning glasses, in particular, these materials are welcoming and long-term stable hosts for impurities. Glasses are thus materials of choice when contemplating the safe stable storage of radioactive waste materials. Of similar or possibly greater importance, secondary organic aerosols (SOAs) are most often in glassy states. Their transformations play a dominant role in the chemistry of the atmosphere, affecting Earth's climate and human health. This research, therefore, addresses issues pertaining to significant problems in society. Its profound importance together with its fundamental nature makes it superbly appropriate for motivating and training students to become scientists.