NTBuilder: Commensurate Construction of Nanotubes from Arbitrary Two-Dimensional Crystals and a Catalog of 20 Million Structures

This paper addresses the challenge that while tens of thousands of 2D crystals are known, their nanotube forms have traditionally been constructed using procedures derived specifically for graphene. The authors develop a general theory of rolling construction applicable to arbitrary 2D crystals and implement it in NTBuilder, an open-source library providing both desktop and web interfaces. The work includes a catalog of 20 million nanotube structures with exact unit cell characterizations, enabling systematic exploration of nanotube geometries beyond conventional materials.