CREST-PRP: Exploring the Quantum Potential Energy Surface of Water and Aqueous Solutions

CREST 博士后研究计划 (CREST-PRP) 为活跃的 CREST 中心的个人早期职业科学家提供两年的研究、培训和指导经验支持。 CREST-PRP 奖项的目标是增加 STEM 领域中代表性不足群体成员的个人在 STEM 劳动力中的存在。 CREST-PRP 奖项表彰具有巨大潜力的研究人员，并支持他们的研究经验，以拓宽他们的视角，促进跨学科互动，并为 CREST-PRP 学者在科学界的领导职位做好准备。该研究项目“CREST-PRP：探索水和水溶液的量子势能面”与 CREST-PRP 的目标直接一致。该项目由纽约城市学院低维系统界面设计和工程组装 CREST 中心的一名研究人员提交，旨在将最初用于描述低温下经典液体行为的势能图 (PEL) 形式扩展到量子液体的情况。该项目将为理解核量子效应如何影响水和水溶液中的液体到玻璃化转变提供重要的见解。量子势能景观形式主义也将为理解量子效应如何影响水的物理和机械性质提供理论基础。从该项目获得的形式主义和数值数据将对从事低温生物材料冷冻保存的科学和工程界、对提高非晶态材料保质期感兴趣的制药和食品行业有用。用于生成和分析该项目结果的代码和脚本将开源、用户友好并可供整个科学界使用。PEL 形式主义过去已应用于研究团簇、原子、生物分子、玻璃的热力学和动力学以及平衡系统的状态方程的计算。这些计算研究是使用经典分子动力学进行的，其中省略了量子效应。该项目将扩展 PEL 形式，其中明确包含核量子效应，使用路径积分模拟来研究 (i) 过冷玻璃水和 (ii) 含有水和离子（Li、Cl-、Na）的水溶液。通过使用量子力学的路径积分公式，量子粒子被映射到由 P 珠映射的虚拟环聚合物上，通过取决于粒子质量和系统温度的谐振弹簧连接。在路径积分方法中，PEL 现在成为粒子质量和温度的函数，这与经典 PEL 不同，在经典 PEL 中粒子质量在定义 PEL 中不起任何作用。该项目将寻求回答量子效应的包含如何影响 PEL 的属性（PEL 的最小值、曲率和深度）、根据 PEL 的属性计算水和水溶液的状态方程，以及水中包含的离子如何影响水中的玻璃化转变。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

The CREST Postdoctoral Research Program (CREST-PRP) provides two years of support for research, training, and mentoring experiences for individual early career scientists at active CREST Centers. The goal of the CREST-PRP awards is to increase the STEM workforce presence of individuals who are members of groups underrepresented in STEM fields. CREST-PRP awards recognize investigators with significant potential and support their research experiences to broaden their perspectives, facilitate interdisciplinary interactions, and prepare CREST-PRP scholars for positions of leadership within the scientific community. The research project, "CREST-PRP: Exploring the Quantum Potential Energy Surface of Water and Aqueous Solutions," is in direct alignment with the CREST-PRP goals. Submitted by a researcher affiliated with the CREST Center for Interface Design and Engineered Assembly of Low-dimensional Systems at the City College of New York, this project aims to extend the potential energy landscape (PEL) formalism that was originally developed to describe the behavior of classical liquids at low temperature to the case of quantum liquids. This project will generate crucial insights into understanding how nuclear quantum effects can influence the liquid to glass transition in water and aqueous solutions. The quantum potential energy landscape formalism will also provide a theoretical basis in understanding how quantum effects influence the physical and mechanical properties of water. The formalism and numerical data obtained from this project will be useful to the scientific and engineering community working on the cryopreservation of biomaterials at low temperatures, pharmaceutical and food industries interested in improving the shelf life of amorphous materials. The codes and scripts used to generate and analyze the results from this project will be made open source, user friendly and available to be used throughout the scientific community.The PEL formalism has been applied in the past to study the thermodynamics and dynamics of clusters, atoms, biomolecules, glasses and in the calculation of the equation of state of equilibrium systems. These computational studies were performed using classical molecular dynamics, where the inclusion of quantum effects are omitted. This project will extend the PEL formalism where nuclear quantum effects are explicitly included, using path integral simulations to study (i) supercooled and glassy water and (ii) aqueous solutions containing water and ions (Li+, Cl-, Na+). By using the path integral formulation of quantum mechanics, the quantum particle is mapped onto a fictitious ring- polymer mapped up of P beads, connected by harmonic springs that depend on the mass of the particle and the temperature of the system. In the path integral approach, the PEL now becomes a function of the mass of the particles and the temperature, distinct from the classical PEL, where the mass of the particle plays no role in defining the PEL. This project will seek to answer how the inclusion of quantum effects, influence the properties of the PEL (minima, curvature, and depth of the PEL), calculate an equation of state for water and aqueous solutions from the properties of the PEL, and how the inclusion of ions in water affects the glass transition in water.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.