Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
J Chem Phys. 2012 Jul 14;137(2):024502. doi: 10.1063/1.4732538.
We identify by ab initio calculations a simple monoclinic carbon in P2/m (C(2h)(1)) symmetry with an alternating zigzag and armchair buckling of the carbon sheets in AA stacking, which is formed via a distinct one-layer by one-layer conversion mechanism along the [210] direction assisted by a large lattice distortion. It is dynamically stable and energetically favorable as well as recently identified orthorhombic W- and monoclinic M-carbon. Moreover, this new phase has a wider band gap than diamond's, and is compatible with the experimental x-ray diffraction data. These results broaden our understanding of the direct graphite-to-diamond phase transition.
我们通过从头算方法确定了一种简单的单斜碳，具有 P2/m（C(2h)(1)）对称性，在 AA 堆叠中，碳片交替出现之字形和扶手椅弯曲，通过沿[210]方向的独特的单层到单层的转换机制形成，该机制由大的晶格畸变辅助。它是动力学稳定的，能量上也是有利的，与最近确定的正交 W-相和单斜 M-相碳相同。此外，这种新相的带隙比金刚石的宽，并且与实验的 X 射线衍射数据相兼容。这些结果拓宽了我们对直接石墨到金刚石相变的理解。
