Using systematic evolutionary structure searching we propose a new carbon allotrope, phagraphene, standing for penta-hexa-hepta-graphene, because the structure is composed of 5-6-7 carbon rings. This two-dimensional (2D) carbon structure is lower in energy than most of the predicted 2D carbon allotropes due to its sp²-binding features and density of atomic packing comparable to graphene. More interestingly, the electronic structure of phagraphene has distorted Dirac cones. The direction-dependent cones are further proved to be robust against external strain with tunable Fermi velocities.

http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.5b02512

https://mipt.ru/en/news/fagrafen_201509

http://mp.weixin.qq.com/s?__biz=MzA5NDQ2NzQyMg==&mid=224914170&idx=5&sn=006fc04565d097ce766e33046c7ce5e3&scene=0#rd