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、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;这一现象在制药、太阳能和半导体制造技术中也产生了无数后果。尽管它的意义，理解晶体成核仍然是一个巨大的挑战问题，无论是原子尺度的空间分辨率所需的和广泛的时间尺度，在其分析中遇到的。除了这些挑战之外，对成核过程中工作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的可靠性和影响力，作为阐明晶体成核的基本机制的有效工具。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需求，该基础设施提供（1）在不同材料和结晶环境中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，以及（3）弥合模拟预测和实验测量之间的差距所需的可缩放性。除了制药，能源和半导体应用外，这样的基础设施将为理解聚合物控制的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的学术专家，旨在部署一个集成的，大规模开源计算套件，能够在现实条件下模拟晶体成核。该软件包将通过将这些方法作为LAMMPS的各个模块进行实施和分发，集成一组有凝聚力的高级计算工具，从而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以下方式进行验证：（1）检查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NaCl和碱土碳酸盐从水溶液中的成核。建议的计算工具包将提高目前的理解纳米晶体成核和随后的晶体生长的热力学和动力学，在表面工程，减少膜污染引起的矿物结垢，无机矿化，和材料合成的直接应用。这项研究的成果将以开放源码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活动，地球日期广播和化学俱乐部演示与高中学生合作进行外展工作。该奖项反映了NSF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.