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与材料理论计划以及化学、生物工程、环境与运输系统部的计算与数据科学与工程及过程系统、反应工程和分子热力学计划资助。晶体成核是自然界中最普遍的过程之一，它也是一种在制药、太阳能和半导体制造技术中具有无数后果的现象。尽管它意义重大，但理解晶体成核仍然是一个巨大的挑战问题，无论是对于所需的原子尺度的空间分辨率，还是在其分析中遇到的广泛的时间尺度。使这些挑战雪上加霜的是，研究人员仍然无法对成核过程中起作用的基本物理机制做出明确的解释。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，以进一步提高分子模拟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，该建议背后的合作研究小组确定了开发关键的网络基础设施的必要性，该基础设施提供(1)模拟不同材料和结晶环境中的结晶成核所需的通用性，(2)模拟自然发生的和与工业相关的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扩展性。除了制药、能源和半导体应用，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，能够在现实条件下模拟晶体成核。该程序包将通过实施和分发这些方法作为LAMMPS的单独模块来集成一套紧密结合的高级计算工具，从而允许大规模应用于具有最先进量子精确潜力的广泛成核问题。该方法和软件将通过(1)检验表面地形对冰成核的作用，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)模拟氯化钠和碱土碳酸盐在水溶液中的成核，来验证方法和软件。拟议的计算工具包将加强目前对纳米晶体成核和随后晶体生长的热力学和动力学的理解，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。这项研究的产品将以开放源码软件的形式提供给更广泛的科学界。调查人员将通过与高中生合作，通过科学奥林匹克活动、地球日期广播和化学俱乐部演示来开展外展工作。该奖项反映了NSF的法定使命，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，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.