US-Czechoslovak Research on Unified Theory and Structure of Subperiodic Subgroups of Crystallographic Space Groups (Condensed Matter Theory)

宾夕法尼亚州立大学的Daniel Litvin博士和捷克物理研究所的Vojtech Kopsky博士合作的这项美国-捷克斯洛伐克研究项目的主要目标是开发一种系统的、统一的理论来定义晶体空间群的次周期子群之间的关系。对于这些群存在各种各样的命名和符号，即二维中的Frieze群、带状群或线群，以及三维空间中的杆群、线性空间群或一维(次周期)群。但是，对于国际结晶学表格中的亚周期基团，还没有完整的标准。研究人员打算为空间群的亚周期子群的轴和起源设定标准，以取代文献中找到的无数选择。他们的努力应该产生一个有用的、标准化的参考，用于根据不可还原的性质对亚周期群进行分类和表征。这项工作应该对研究凝聚态物质和材料科学主题的研究界的基础设施作出重要贡献。这个凝聚态理论项目通过使美国和东欧的顶尖专家能够将互补的人才结合在一起，并在彼此感兴趣和有能力的领域汇集研究资源，实现了促进科学知识的计划目标。

The primary objective of this U.S.-Czechoslovakia research project between Dr. Daniel Litvin of Pennsylvania State University and Dr. Vojtech Kopsky of the Czechoslavok Institute of Physics is to develop a systematic, unified theory for defining relationships among subperiodic subgroups of crystallographic space groups. There exists a wide variety of nomenclature and notation for these groups, i.e., Frieze groups, ribbon groups or line groups in two-dimensions, and rod groups, linear space groups or one-dimensional (subper- iodic) groups in three-dimensional space. But no complete standards exist for the subperiodic groups in the International Tables for Crystallography. The researchers intend to set the standards for the orientation of axes and origins of the subperiodic subgroups of the space groups to replace the myriad of choices found in the literature. Their efforts should yield a useful, standardized reference for classifying and characterizing subperiodic groups by their irreducible qualities. Such a work should be an important contribution to the infrastructure of the research communities examining topics in condensed matter and materials science. This project in condensed matter theory fulfills the program objective of advancing scientific knowledge by enabling leading experts in the United States and Eastern Europe to combine complementary talents and pool research resources in areas of strong mutual interest and competence.