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

该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将使用混合基簇扩展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，这些结构迄今为止还无法通过实验确定。这将包括：（a）具有一维和二维周期性的CuPd和CuMn的结构，（B）在这些系统中，空位形成特殊的空间排列的前过渡金属氮化物和碳化物中的空位的有序化，和（c）Mo-Ta和Nb-W的基本相行为的确定。这些材料系统的研究还需要开发新的方法：1。发展新的动力学-蒙特卡罗程序来研究微结构的演化。2.确定合金系统基态的“遗传算法”方法的发展。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;开发其他研究人员可以免费获得的研究合金的工具;为本科生，特别是那些来自物理学和材料科学领域代表性不足的学生，提供研究经验，计算培训，和一对一的教师指导。拟议的合作涉及埃尔兰根德国的一个小组，特别是对材料的低维方面的兴趣。该NSF项目由多学科活动办公室、材料研究部和国际办公室（西欧）共同资助，是NSF和欧洲之间的材料研究合作活动（NSF 02-135）。该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、硬度和导电性等特性。然而，许多金属间化合物的结构是未知的实验。PI将使用预测稳定晶体结构的第一原理方法来研究非理想化学计量的不同金属间化合物。PI还将开发其他方法和代码，以促进对此类系统的研究。该项目更广泛的影响包括：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，这些工具将免费提供给其他研究人员;并为本科生，特别是那些来自物理学和材料科学领域代表性不足的群体的学生提供研究经验，计算培训和一对一的教师指导。拟议的合作涉及埃尔兰根德国的一个小组，特别是对材料的低维方面的兴趣。该项目由多学科活动办公室、材料研究部和国际办公室（西欧）共同资助，是NSF和欧洲之间材料研究的合作活动（NSF 02-135）。 该项目是与德国埃尔兰根的埃尔朗根-农贝格大学合作开展的。

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.***