Figure6

Figure 6. Results of variable-composition calculations on the $$ \eta $$-Fe$$ _2 $$C(111) surface. (A) A schematic representation of the variable-composition search, where "-3C" indicates three fewer carbon atoms compared to the unreconstructed structure; (B) Side and top views of unreconstructed and reconstructed structures of the most stable configuration at the lower $$ \Delta \mu _\text{C} $$ limit; (C) Plot of the relative surface energies of the most stable reconstructions with different total carbon numbers against $$ \Delta \mu _\text{C} $$.