NTBuilder：从任意二维晶体相称构建纳米管及2000万结构目录
NTBuilder: Commensurate Construction of Nanotubes from Arbitrary Two-Dimensional Crystals and a Catalog of 20 Million Structures
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中文总结 AI 辅助
提出通用卷曲构建理论并开发NTBuilder开源库，从任意二维晶体高效构建纳米管，生成含2033万个结构的目录，其中57.1%无键变化，支持第一性原理计算。
中文摘要 AI 辅助
尽管目前已知数万种二维（2D）晶体，但它们所能形成的纳米管通常是为单一材料、采用源自石墨烯的方法构建的。在此，我们发展了一种针对任意二维晶体的卷曲构建的通用理论，并将其实现于\ tbuilder{}（NanoTube Builder）这一开源库中，该库提供桌面端和网页端界面。我们将纳米管精确单胞的尺寸表示为基于晶格度量构建的单一有理数的简化形式，这解释了为何三角和四方晶格总是以较小的单胞闭合，而矩形、有心矩形和斜方晶格则可能需要大出多个数量级的单胞。最优近似单胞是第二个数的最佳有理逼近，因此可以选择一个足够小、适用于第一性原理计算的单胞，同时其与周期性的偏差可控，如在联苯网络（biphenylene network）中，该单胞比精确单胞小八个数量级。考虑卷曲后，17个平面群简化为七种不同的手性映射；没有水平镜面的层的卷曲方向定义了不同的纳米管；曲率导致形成或断裂的键通过与平面层逐对比较而被检测出来。同一框架还可组装多壁纳米管（其各壁共享一个轴向周期）、周期性束以及保持周期性的应变或扭曲结构。将该方法应用于46,403种不同的二维体系，生成了一个包含20,334,372个纳米管的公共目录，其中57.1%在卷曲时无键变化。所有结构均可直接导出为第一性原理和分子动力学代码的输入文件。
英文摘要
Although tens of thousands of two-dimensional (2D) crystals are now known, the nanotubes they can form are usually constructed for individual materials, using procedures derived for graphene. Here, we develop a general theory of the rolling construction for arbitrary 2D crystals and implement it in \ntbuilder{} (NanoTube Builder), an open-source library with desktop and web interfaces. We express the size of the exact unit cell of a tube through the reduced form of a single rational number built from the lattice metric, which explains why triangular and square lattices always close with small cells, whereas rectangular, centered rectangular, and oblique lattices can require cells larger by many orders of magnitude. The optimal approximate cells are the best rational approximations of a second number, so that a cell small enough for first-principles calculations can be chosen with a controlled departure from periodicity, as in the biphenylene network, where such a cell is eight orders of magnitude smaller than the exact one. The 17 plane groups reduce to seven distinct chirality maps once rolling is taken into account, the rolling sense of layers without a horizontal mirror defines distinct tubes, and bonds formed or broken by curvature are detected pair by pair against the flat layer. The same framework assembles multiwalled tubes whose walls share one axial period, periodic bundles, and strained or twisted structures that remain periodic. Applied to 46,403 distinct 2D systems, it produced a public catalog of 20,334,372 nanotubes, of which 57.1\% show no bond change upon rolling. All structures can be exported directly as input for first-principles and molecular dynamics codes.
