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

这个由宾夕法尼亚州立大学的Daniel Litvin博士和捷克斯洛伐克物理研究所的Vojtech Kopsky博士合作的美国-捷克斯洛伐克研究项目的主要目标是发展一个系统的、统一的理论来定义晶体空间群的次周期子群之间的关系。这些群有各种各样的命名和符号，即二维空间中的Frieze群、带状群或线群，以及三维空间中的棒状群、线性空间群或一维（亚周期）群。但是，对于国际晶体学表中的亚周期群，目前还没有完整的标准。研究人员打算为空间群的次周期子群的轴线方向和起源设定标准，以取代文献中发现的无数选择。他们的努力应该产生一个有用的，标准化的参考分类和特征的亚周期群的不可约的性质。这样的工作应该是一个重要的贡献，研究社区的基础设施，研究凝聚态和材料科学的主题。这个凝聚态理论项目实现了推进科学知识的计划目标，使美国和东欧的领先专家能够在共同感兴趣和能力强的领域结合互补的人才和集中研究资源。

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.