(a) Band structures for pristine (black curves) and deformed (blue curves) silicene with a 4 × 4 supercell. In the deformed case, the Nb atoms are removed. Insets: magnified bands near the K points and the optimized structure around the Nb. (b) and (c) The band structures of silicene adsorbed with Nb without (b) and with (c) the consideration of spin polarization, respectively. The contributions from Si 3p/Nb 4d states to the bands are denoted by the orange/blue circles. The inset in panel (c) is the spatial distribution of the spin difference. (d) The corresponding bands of panel (c) with the SOC. The E_F is set at energy zero. Reprinted with permission from Ref. [20]. Copyright 2013 by the American Physical Society.