Elements: Open-source tools for block polymer phase behavior

嵌段聚合物是通过在其末端结合一个或多个不同的聚合物分子而形成的分子。当一种嵌段聚合物的液体被冷却时，它会自发地形成一种纳米级的有序结构，这种结构由嵌段聚合物的化学性质决定。理解不同有序状态的选择既有基础意义又有实际意义。在基本方面，嵌段聚合物为研究软物质的自组装和结晶秩序的形成提供了一个重要的模型系统。在实践层面上，用具有显著不同特性的可控组分排列构建材料的能力（例如，玻璃球嵌入橡胶基体）可以实现新的应用。计算在基础研究和这些技术应用中都扮演着重要的角色，它为分析材料的选择提供指导，并为解释结果提供框架。该项目将开发一个开源软件包，使嵌段聚合物研究人员能够在自己的研究中轻松使用最先进的计算工具。该项目的长期目标是在嵌段聚合物理论和实验社区的背景下，广泛使用基于现场的模拟工具，自然地补充基于颗粒的分子动力学模拟方法来研究嵌段聚合物的性质。该项目还为研究生和本科生提供了研究最先进的模拟方法和高性能科学计算培训的机会。提议的开源软件包将在c++实现的通用框架下实现自洽场理论（SCFT）和场理论模拟（FTS）。该软件包将包括SCFT工具，该工具建立在成功的聚合物自一致场（PSCF）周期性系统软件包的基础上，提供高级聚合物物理研究所需的全套功能。这个新的程序包，完全用一种新的语言重写，具有更灵活的设计，将能够在gpu或多核cpu上加速计算，有效地处理特殊对称性问题，以及处理复杂的边界，如聚合物接枝纳米颗粒和图案表面。一套单独的FTS程序将允许用户实现完全波动模型的复杂朗之万抽样或更有效的随机模拟形式，其中包括对保持均匀密度的非特异性空间相互作用的近似处理。还将开发输入/输出工具，以降低使用软件的障碍。工作的传播将包括一个项目网站，它将为潜在用户提供背景资料和文件链接，以及一个在线教程讲习班，向更广泛的社区介绍该软件及其功能。该项目由计算机和信息科学与工程理事会的先进网络基础设施办公室资助，数学和物理科学理事会的材料研究司和化学司以及工程理事会的化学、生物工程、环境和运输系统司也提供资金。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。

Block polymers are molecules formed by bonding one or more different polymer molecules at their ends. When a liquid of block polymers is cooled, it spontaneously forms an ordered structure with nanoscale domain sizes and a structure that is dictated by the chemistry of the block polymer. Understanding the selection of different ordered states has both fundamental and practical implications. On the fundamental side, block polymers provide an important model system for examining self-assembly and the formation of crystalline order in soft matter. At a practical level, the ability to construct materials with a controllable arrangement of components with dramatically different properties (e.g., glassy spheres embedded in a rubbery matrix) enables novel applications. Computation plays an important role for both fundamental studies and these technological applications by providing guidance towards the selection of materials to analyze and a framework for interpreting the results. This project will produce an open-source software package that enables block polymer researchers to easily use state-of-the-art computational tools in their own research. The long-term goal of the project is to achieve, within the context of the block polymer theory and experimental community, a widespread use of field-based simulation tools that naturally complement particle-based molecular dynamics simulation methods for studying block polymer properties. This project also provides graduate students and undergraduates with the opportunities to work on state-of-the-art simulation methods and training in high-performance scientific computing.The proposed open-source software package will enable self-consistent field theory (SCFT) and field theoretic simulations (FTS) under a common framework implemented in C++. The package will include SCFT tools that build on the successful Polymer Self Consistent Field (PSCF) software package for periodic systems to provide the full suite of functionality required for advanced polymer physics research. This new package, entirely rewritten in a new language and with a more flexible design, will enable accelerated calculations on either GPUs or multicore CPUs, efficient treatment of problems with special symmetries, and treatment of complex boundaries such as polymer-grafted nanoparticles and patterned surfaces. A separate set of FTS programs will allow the user to implement either complex Langevin sampling of the fully fluctuating model or a more efficient form of stochastic simulation that involves an approximate treatment of non-specific steric interactions that maintain a uniform density. Input/output tools will also be developed to lower the barrier to usage of the software. Dissemination of the work will include a project website, which will provide background for potential users and links to documentation, and an online tutorial workshop that will introduce the software and its capabilities to the broader community. This project is funded by the Office of Advanced Cyberinfrastructure in the Directorate for Computer and Information Science and Engineering, with the Division of Materials Research and the Division of Chemistry in the Directorate for Mathematical and Physical Sciences and the Division of Chemical, Bioengineering, Environmental and Transport Systems in the Directorate for Engineering also contributing funds.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.