CDS&E: Collaborative Research: An integrated computational suite for large-scale modeling of crystal nucleation

该项目由材料研究部的凝聚态物质和材料理论项目以及化学、生物工程、环境和运输系统部的计算和数据科学与工程与过程系统、反应工程和分子热力学项目资助。晶体成核是自然界中最普遍的过程之一；这一现象也对制药、太阳能和半导体制造技术产生了无数的影响。尽管其意义重大，但理解晶体成核仍然是一个巨大的挑战问题，无论是所需的原子尺度空间分辨率还是在分析中遇到的广泛时间尺度。使这些挑战更加复杂的是，对成核过程中起作用的基本物理机制的明确解释仍然困扰着研究人员。计算算法和硬件的最新进展为设计实用策略创造了新的机会，以进一步提高分子建模作为阐明晶体成核基本机制的有效工具的可靠性和影响。因此，该提案背后的合作研究小组确定了开发关键网络基础设施的必要性，该基础设施提供(1)跨不同材料和结晶环境模拟晶体成核所需的多功能性，(2)模拟自然发生和工业相关结晶过程所需的计算效率，(3)弥合模拟预测和实验测量之间差距所需的可扩展性。除了制药、能源和半导体应用之外，这样的基础设施将为理解聚合物控制结晶和生物矿化铺平道路，将使开发新的飞机防冰策略成为可能，并将促进生物启发材料的设计。这项研究将汇集分子模拟方法开发和实施方面的学术专家，旨在部署一个集成的、大规模的开源计算套件，使在现实条件下模拟晶体成核成为可能。该包将通过实现和分发这些方法作为LAMMPS的单个模块，集成一套有凝聚力的先进计算工具，这允许大规模应用于具有最先进量子精确势的广泛成核问题。该方法和软件将通过(1)研究表面形貌对冰成核的作用，并对实验确定的无机冰成核剂的成核效率进行基准测试，以及(2)模拟水溶液中NaCl和碱土碳酸盐的成核。所提出的计算工具包将增强当前对纳米级晶体成核和随后晶体生长的热力学和动力学的理解，并直接应用于表面工程、减少矿物结垢引起的膜污染、无机矿化和材料合成。这项研究的成果将以开源软件的形式提供给更广泛的科学界。调查人员将通过科学奥林匹克竞赛活动、地球日期广播和化学俱乐部演示与高中生合作，开展推广工作。将在服务不足人口众多的地区作出特别努力，从而促进对STEM学科的多样化和公平的兴趣和参与。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project is funded by the Condensed-Matter-and-Materials-Theory program in the Division of Materials Research and by the programs in Computational and Data-Enabled Science and Engineering and Process Systems, Reaction Engineering, and Molecular Thermodynamics in the Division of Chemical, Bioengineering, Environmental, and Transport Systems.Crystal nucleation is one of the most ubiquitous processes in nature; it is a phenomenon that also has countless consequences in pharmaceutical, solar energy, and semiconductor manufacturing technologies. Despite its significance, understanding crystal nucleation remains a grand-challenge problem, both for the atomistic-scale spatial resolution required and the widely ranging timescales that are encountered in its analysis. Compounding these challenges, definitive explanations of the fundamental physical mechanisms at work during nucleation continue to elude researchers. Recent advances in computational algorithms and hardware have created new opportunities for devising practical strategies to further the reliability and impact of molecular modeling as an effective tool to elucidate the fundamental mechanisms underlying crystal nucleation. Therefore, the collaborative research group behind this proposal identified the need for developing a critical cyber infrastructure that offers (1) the versatility necessary to model crystal nucleation across different materials and crystallization environments, (2) the computational efficiency required to simulate naturally occurring and industrially relevant crystallization processes, and (3) the scalability needed to bridge the gap between simulation predictions and experimental measurements. In addition to pharmaceutical, energy, and semiconductor applications, such an infrastructure will pave the way for understanding polymer-controlled crystallization and biomineralization, will make it possible to develop new aircraft anti-icing strategies, and will facilitate the design of bio-inspired materials.This research will bring together academic experts in molecular simulation method development and implementation, aiming to deploy an integrated, large-scale open-source computational suite that enables modeling crystal nucleation under realistic conditions. This package will integrate a cohesive set of advanced computational tools through an implementation and distribution of these methods as individual modules of LAMMPS, which allows large-scale applications to a broad range of nucleation problems with state-of-the-art quantum-accurate potentials. The methodology and software will be validated through (1) examining the role of surface topography on ice nucleation and benchmarking the nucleation efficiency of experimentally identified inorganic ice nucleators, and (2) modeling the nucleation of NaCl and alkaline earth carbonates from aqueous solution. The proposed computational toolkit will enhance current understanding of the thermodynamics and kinetics of nanoscopic crystal nucleation and subsequent crystal growth, with direct applications in surface engineering, reduction of membrane fouling induced by mineral scaling, inorganic mineralization, and materials synthesis. The products of this research will be made available to the broader scientific community in the form of open-source software. The investigators will engage in outreach efforts by working with high-school students through a Science Olympiad event, EarthDate broadcasts, and Chemistry Club demonstrations. Special efforts will be deployed in areas with a large presence of underserved populations, thus fostering diverse and equitable interest and involvement in STEM disciplines.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.