NSF-Europe: Computer-Based Discovery of Novel, Low-Temperature Structures in Intermetallic Compounds

这一NSF-欧洲奖支持金属间化合物的国际合作研究。许多金属间化合物的结构在实验上是未知的。PI将使用混合基团簇展开结合现代统计力学基态搜索技术来预测金属间化合物的稳定结构，这些结构到目前为止还没有得到实验确定。这将包括：(A)具有一维和二维周期的CuPd和CuMn的结构；(B)早期过渡金属氮化物和碳化物中空位的有序性--在这些系统中，空位形成特殊的空间排列；以及(C)确定Mo-Ta和Nb-W的基本相行为。对这些材料体系的研究还需要开发新的方法：1.开发新的动力学-蒙特卡罗程序来研究微结构的演化。2.发展了确定合金系统基态的“遗传算法”方法。3.开发处理bcc基合金的混合基团簇扩展代码。该项目的更广泛影响包括：在理解技术上重要的材料方面取得进展的潜力；开发研究合金的工具，供其他研究人员免费使用；为本科生，特别是那些来自物理学和材料科学中代表性不足的群体的本科生提供研究经验、计算培训和一对一的教员指导。拟议中的合作涉及德国Erlangen的一个小组，该小组特别以对材料的低维方面感兴趣而闻名。该NSF项目由多学科活动办公室、材料研究司和国际办公室(西欧)共同资助，作为NSF和欧洲之间在材料研究方面的合作活动(NSF 02-135)。%本NSF-欧洲奖支持金属间化合物的国际合作研究。晶体结构决定了延展性、硬度和导电性等性能。然而，许多金属间化合物的结构在实验上是未知的。PI将使用第一原理方法预测稳定的晶体结构，以非理想化学计量研究不同的金属间化合物。国际和平研究所还将开发更多的方法和代码，以促进对这种系统的研究。该项目的更广泛影响包括：在理解技术上重要的材料方面取得进展的潜力；开发研究合金的工具，供其他研究人员免费使用；为本科生，特别是那些来自物理学和材料科学中代表性不足的群体的本科生，提供研究经验、计算培训和一对一的教职指导。拟议中的合作涉及德国Erlangen的一个小组，该小组特别以对材料的低维方面感兴趣而闻名。该NSF项目由多学科活动办公室、材料研究司和国际办公室(西欧)共同资助，作为NSF和欧洲之间在材料研究方面的合作活动(NSF 02-135)。该项目是与德国埃尔兰根的Erlangen-Numberg大学合作开展的。

This NSF-Europe award supports international collaborative research on intermetallic compounds. The structure of many intermetallics is unknown experimentally. The PI will use a Mixed-Basis Cluster Expansion in conjunction with modern statistical mechanics ground state search techniques to predict stable structures for intermetallics that have so far eluded experimental determination. This will include: (a) structures of CuPd and CuMn with one- and two-dimensional periodicities, (b) ordering of vacancies in early transition metal nitrides and carbides - in these systems, the vacancies form peculiar spatial arrangements, and (c) determination of the fundamental phase behavior of Mo-Ta and Nb-W. The study of these material systems also requires development of new methodologies: 1. Development of new kinetic-Monte Carlo codes to study evolution of microstructures. 2. Development of a "genetic algorithm" approach to determining ground states in alloy systems. 3. Development of mixed-basis cluster expansion codes that handle BCC-based alloys.The broader impacts of the project include: potential for advances in understanding technologically important materials; developing tools for studying alloys that will be freely available to other researchers; and providing undergraduate students, especially those from under-represented groups in physics and materials science, with research experience, training in computation, and one-to-one faculty mentoring. The proposed collaboration involves a group in Erlangen Germany, particularly noted for its interest in low-dimensional aspects of materials. This NSF project is co-funded by the Office of Multidisciplinary Activities, the Division of Materials Research, and the International Office (Western Europe) as a Cooperative Activity in Materials Research between the NSF and Europe (NSF 02-135).%%%This NSF-Europe award supports international collaborative research on intermetallic compounds. Crystal structure determines properties such as ductility, hardness, and conductivity. Yet the structure of many intermetallics is unknown experimentally. The PI will use a first principles methodology for predicting stable crystal structures to study different intermetallic compounds at non-ideal stoichiometries. The PI will also development additional methodologies and codes to facilitate study such systems. The broader impacts of the project include: potential for advances in understanding technologically important materials; developing tools for studying alloys that will be freely available to other researchers; and providing undergraduate students, especially those from under-represented groups in physics and materials science, with research experience, training in computation, and one-to-one faculty mentoring. The proposed collaboration involves a group in Erlangen Germany, particularly noted for its interest in low-dimensional aspects of materials. This NSF project is co-funded by the Office of Multidisciplinary Activities, the Division of Materials Research, and the International Office (Western Europe) as a Cooperative Activity in Materials Research between the NSF and Europe (NSF 02-135). This project is being carried out in collaboration with the Universitat Erlangen-Numberg in Erlangen, Germany.***