Bending-induced phase transition in monolayer black phosphorus
Pan Dou-Xing†a),c), Wang Tzu-Chianga), Guo Wan-Linb)
       
Structures of BP in bent states. Bending moment M is perpendicular to (a) armchair direction (armchair bending) and (b) zigzag direction (zigzag bending). ArmPNT means the armchair single-walled phosphorus nanotube, and zigPNT the zigzag one.