Van der Waals Approach to Systematic Coarse-Graining

宾夕法尼亚州立大学的William Noid获得了化学部化学理论、模型和计算方法项目的奖励，以开发用于模拟液体和聚合物的热力学和界面性质的理论方法和计算工具。 计算机模拟为解决技术挑战和指导具有所需性能的新型材料的设计提供了强大的洞察力。 虽然使用原子级详细模型的模拟通常非常准确，但它们无法提供必要的效率来解决与材料设计相关的长时间和时间尺度。 相比之下，较低分辨率的粗粒度模型提供了上级效率，但目前提供有限的精度，并且通常需要为每个新系统和环境进行大量的参数化。 Noid教授和他的同事开发了理论方法来提高粗粒度模型的准确性，并扩展其适用范围。此外，诺伊德教授组织了一个代际科学俱乐部，在更广泛的社区内促进终身科学教育，同时将所有年龄段的学生融入科学事业。 这个项目开发和验证了一个货车德瓦尔斯（vdW）的方法，以提高自底向上的多尺度方法的可转移性和热力学性质。 由平均力的多体势的精确分解激发，这是粗粒度（CG）模型的正确势。 这个模型完美地再现了基础原子模型的结构和热力学性质。 vdW方法：（1）采用领先的变分方法来确定精确描述结构性质的有效势，（2）开发新的变分方法来精确模拟热力学性质。 特别是，这项工作扩展了压力匹配变分原理建模密度波动的非均匀和界面系统。 从不同的变分方法得到的潜力的比较提供了深入了解它们的熵分量，并允许其可转移性的预测估计。最终，这项工作可能会开发预测CG模型，用于非常准确和有效的模拟研究聚合物基电池中的水界面介观自组装和传导。

William Noid of the Pennsylvania State University is supported by an award from the Chemical Theory, Models and Computational Methods Program in the Chemistry Division to develop theoretical methods and computational tools for simulating the thermodynamic and interfacial properties of liquids and polymers. Computer simulations provide powerful insight for addressing technological challenges and for guiding the design of novel materials with desired properties. While simulations with atomically detailed models are often very accurate, they do not provide the necessary efficiency for addressing the long length and time scales that are relevant for materials design. In contrast, lower resolution coarse-grained models provide superior efficiency, but currently provide limited accuracy and often require extensive parameterization for each new system and environment. Professor Noid and his coworkers develop theoretical methods for improving the accuracy of coarse-grained models, as well as for extending their range of applicability. Additionally, Professor Noid organizes an intergenerational science club that promotes life-long scientific education within the broader community, while integrating students of all ages into the scientific enterprise. This project develops and validates a van der Waals (vdW) approach for improving both the transferability and also the thermodynamic properties of bottom-up multiscale methods. Motivated by an exact decomposition of the many-body potential of mean force, which is the correct potential for a coarse-grained (CG) model. This model perfectly reproduces both the structural and thermodynamic properties of an underlying atomistic model. The vdW approach: (1) adopts leading variational methods to determine effective potentials that accurately describe structural properties and (2) develops new variational methods to accurately model thermodynamic properties. In particular, the work extends a pressure-matching variational principle for modeling density fluctuations in inhomogeneous and interfacial systems. The comparison of potentials obtained from different variational approaches provides insight into their entropic components and allow for predictive estimates of their transferability. Ultimately, this work may develop predictive CG models for exceedingly accurate and efficient simulation studies of mesoscale self-assembly at aqueous interfaces and conduction in polymer-based batteries.