Nonequilibrium Molecular Dynamics: Dynamical Consistency Across Scales

在化学系化学理论、模型和计算方法(CTMC)计划的支持下，约翰霍普金斯大学的Rigoberto Hernandez教授和他的团队将致力于在多个尺度上推进描述分子科学的规则。使用模拟和理论来预测和设计化学的一个根本挑战是要求这样的系统必须以原子分辨率、系统运行的规模(通常与烧杯或化学精炼厂一样大)以及介于两者之间的一切来指定。电子的粗粒化，允许全原子分子动力学的传播，已经被证明在揭示分子和具有近10亿个原子的组件的性质方面至关重要。埃尔南德斯教授将开发粗粒度的表示法和运动方程，以准确地描述从十亿到十七分之一个原子的体系在长度和时间上的中等尺度上的分子特定溶液和材料。埃尔南德斯博士还将通过他对学生、教职员工、化学教师和更广泛的受众的领导和指导，通过增加化学企业内的多样性、公平性和包容性的方法，全面推动科学的发展。约翰·霍普金斯大学的里戈贝托·埃尔南德斯将致力于促进对化学系统的理解和工具的传播，这些化学系统在结构和动态上是一致的，即可以在每个尺度上准确和准确地描述可观察性及其非平衡行为。具体地说，他的工作的主要目标是：(I)使用降维模型表征由宏观尺度扰动驱动的分子到中尺度系统的远离平衡的动力学；(Ii)发展理论来预测包含多个粒子的过程中非平衡路径的内在路径，该路径被跨多个空间和时间尺度保存；以及(Iii)提出复杂溶剂的随机硬核(SHC)模型，对所提出的算法进行结构和动力学一致性的基准测试，并开发一个新的框架来近似识别在多时间和长度尺度上表现出层级相互作用的多相化学系统中的路径。Hernandez博士还参与并将继续参与以下工作：(I)扩大化学动力学中理论和计算工具的使用，使其不局限于其开发者，(Ii)在课堂内外的本科生和研究生教育中增加对化学的学习和欣赏，(Iii)吸引公众参与，以及(Iv)通过他指导的开放式化学多样性合作(ORED)和学术领导力培训(ALT)研讨会，帮助多样化研究-活跃的化学系的教员。他的研究成果将通过同行评议的出版物、EveryWhere Chem上的帖子以及科学和公开讲座广泛传播。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

WIth support from the Chemical Theory, Models and Computational Methods (CTMC) program in the Division of Chemistry, Professor Rigoberto Hernandez of Johns Hopkins University and his team will work to advance the rules describing molecular science at multiple scales. A fundamental challenge to the use of simulation and theory to predict and design chemistry is the requirement that such systems must be specified at atomic resolution, at the scale in which the system functions (generally as large as beaker or a chemical refinery), and everything in between. The coarse- graining of electrons, allowing for the propagation of all-atom molecular dynamics has already proved to be critical in revealing the properties of molecules and assemblies with nearly up to a billion atoms. Professor Hernandez will develop coarse-grained representations and the equations of motion needed to accurately describe molecular-specified solutions and materials through the middle scales in length and time for systems ranging from a billion to a septillion atoms. Dr. Hernandez will also advance science generally through his leadership and mentoring of students, staff, chemistry faculties and broader audiences through approaches increasing diversity, equity and inclusion within the chemical enterprise.Rigoberto Hernandez of Johns Hopkins University will work to advance understanding and tools for propagating chemical systems that are structurally and dynamically consistent in the sense that observables and their non-equilibrium behavior can be accurately and precisely described at every scale. Specifically, the major objectives of his work are to: (i) characterize far-from-equilibrium dynamics of molecular to mesoscale systems driven by macroscale disturbances using reduced-dimensional models; (ii) develop the theory to predict the intrinsic pathways for nonequilibrium pathways in processes involving many particles heterogeneously which is preserved across multiple space and time scales, and (iii) advance the stochastic hard core (SHC) model for complex solvents, benchmark the proposed algorithms for structural and dynamical consistency, and develop a new framework for approximately identifying the pathways in heterogeneous chemical systems exhibiting a hierarchy of interactions at multiple time and length scales. Dr. Hernandez has also been involved and will continue to be involved in efforts to (i) broaden the use of theoretical and computational tools in chemical dynamics beyond its developers, (ii) increase learning and appreciation of chemistry in the education of undergraduate students and graduate students both inside and outside of the classroom, (iii) engage the general public, and (iv) help diversify the faculty in research-active chemistry departments through his direction of the Open Chemistry Collaborative in Diversity Equity (OXIDE) and the Academic Leadership Training (ALT) workshops. His research findings will be disseminated widely through peer-reviewed publications, and postings on EveryWhereChem, and through scientific and public lectures.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.