Bending-induced phase transition in monolayer black phosphorus
Pan Dou-Xing†a),c), Wang Tzu-Chianga), Guo Wan-Linb)
       
Structure of 2D puckered honeycomb BP. The yellow part indicates a unit cell and lattice vectors a 1 and a 2 along armchair( n ,0) and zigzag(0, n ) directions, respectively.