The edge structures of two-dimensional materials are important for the property control of corresponding nanoribbons, but possible edge reconstructions are difficult to resolve. Taking phosphorene nanoribbons as an example, we have employed the structure-searching program IM²ODE to discover new structures for both zigzag and armchair edges of bare phosphorene nanoribbons. The edge atoms of these low-energy nanoribbons are generally 3-fold coordinated, and the edge energies are significantly lower than those directly cut from the monolayer. Moreover, we can build low-energy sinuous edges along the diagonal direction based on the bonding features of phosphorus atoms. Further electronic structure studies also reveal that zigzag phosphorene nanoribbons undergo cell doubling and metal-insulator transition similar to Peierls distortion, indicating that the edges experience self-passivation and become stabilized. As similar edge reconstructions can exist in many other two-dimensional materials and it may be difficult to construct the edges by hand, our structure-searching approach provides reliable insights and certain rules can be discovered to elucidate various structure reconstructions.

二维材料的边缘结构对于相应纳米带的性能控制很重要，但可能的边缘重构很难解决。以磷烯纳米带为例，我们使用结构搜索程序 IM ² ODE 来发现裸磷烯纳米带的锯齿形和扶手椅边缘的新结构。这些低能纳米带的边缘原子通常是3重配位的，边缘能量明显低于直接从单层上切下来的原子。此外，我们可以根据磷原子的键合特征沿对角线方向构建低能蜿蜒边缘。进一步的电子结构研究还表明，之字形磷烯纳米带经历了类似于 Peierls 畸变的细胞倍增和金属-绝缘体转变，表明边缘经历了自钝化并变得稳定。由于类似的边缘重建可以存在于许多其他二维材料中，并且手工构建边缘可能很困难，因此我们的结构搜索方法提供了可靠的见解，并且可以发现某些规则来阐明各种结构重建。