Figure 1
From: Tunable and sizable band gap in silicene by surface adsorption
Structures of the Na-covered m × m silicene supercell.
(a–e) The adsorption coverage is N = 3.1%, 5.6%, 12.5%, 16.7% and 50.0%, respectively, for m = 4, 3, 2, 
and 1. The rhombi plotted in black line represent the supercells at different coverages. (f) Top and side views of an Na-covered silicene supercell over the h-BN sheet with N = 12.5%. d0: the silicene buckling; d1: the distance between Na and the top-surface silicene; d2: the distance between h-BN and the bottom-surface of silicene.
