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劳动力的存在，这些个人是STEM领域代表性不足的群体的成员。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，以拓宽他们的视野，促进跨学科互动，并为CREST-PRP学者在科学界担任领导职位做好准备。“CREST-PRP：探索水和水溶液的量子势能面”的研究项目与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中心的一名研究人员提交，旨在将最初为描述经典液体在低温下的行为而开发的势能景观(PEL)形式论扩展到量子液体的情况。这个项目将对理解核量子效应如何影响水和水溶液中的液体到玻璃的转变产生关键的见解。量子势能景观形式论也将为理解量子效应如何影响水的物理和力学性质提供理论基础。从该项目获得的形式和数值数据将对致力于低温生物材料低温保存的科学和工程界、对改善非晶态材料的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是开源的、用户友好的，并可供整个科学界使用。过去，PEL形式论曾被应用于研究团簇、原子、生物分子、玻璃的热力学和动力学，以及在平衡系统的状态方程计算中。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。这个项目将扩展PEL公式，其中显式包括核量子效应，使用路径积分模拟来研究(I)过冷和玻璃水以及(Ii)含有水和离子(Li，Cl-，Na)的水溶液。利用量子力学的路径积分公式，将量子粒子映射到一个由P个珠子映射而成的虚拟的环聚合物上，由依赖于粒子质量和系统温度的简谐弹簧连接起来。在路径积分方法中，PEL现在变成了粒子质量和温度的函数，这与经典的PEL不同，在经典的PEL中，粒子的质量对定义PEL没有作用。这个项目将寻求回答如何包含量子效应，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，以及水中离子的包含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优势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.