Recently, the long less-known Form II red phosphorus (RP) (viz. Type II RP) was ascertained by the state-of-the-art 3-dimensional electron diffraction technique with a triclinic lattice, completely distinct from other known elemental phosphorus and leaving atomic coordinates not determined. The cell composed of ∼250 atoms might exceed the capacity of current readily available crystal structure search packages, which have been widely applied to systems with several tens of atoms. Besides, mistaking Form II RP for violet phosphorus is still surprisingly common in the studies on allotropic phosphorus due to misinterpretations on JCPDS card #00-044-0906. Herein, by reproducing annealing synthesis and cell relaxation of structures obtained in the literature, we verified two former crystal structures for Form II RP to be wrong and explained how the misinterpretations have occurred. Then, on the basis of experimental lattice data, we provided possible Form II RP models containing atomic positions by a nearly exhaustive high-throughput stepwise crystal structure search approach optimized by molecular mechanics, machine-learned force field, and density functional theory in succession. The energetic stability of Form II RP was found to rank between white phosphorus and black phosphorus, similar to the nanorod modifications.

中文翻译：

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通过逐步晶体结构搜索评估 II 型红磷的结构多样性


最近，通过最先进的三维电子衍射技术确定了长期以来鲜为人知的 II 型红磷 (RP)（即 II 型 RP），其具有三斜晶格，与其他已知元素磷完全不同并留下原子坐标未确定。由约 250 个原子组成的单元可能超出当前容易获得的晶体结构搜索包的容量，这些搜索包已广泛应用于具有数十个原子的系统。此外，由于对 JCPDS 卡 #00-044-0906 的误解，在同素异形磷的研究中，将 Form II RP 误认为紫磷仍然很常见。在此，通过重现文献中获得的结构的退火合成和细胞弛豫，我们验证了Form II RP的两种先前晶体结构是错误的，并解释了错误解释是如何发生的。然后，在实验晶格数据的基础上，我们通过分子力学、机器学习力场和密度泛函理论优化的近乎详尽的高通量逐步晶体结构搜索方法，提供了可能的包含原子位置的II型RP模型。研究发现，II 型 RP 的能量稳定性介于白磷和黑磷之间，与纳米棒改性类似。