Figure 2. Formation energy (orange y-axis) and binding energy (cyan y-axis) of (Zr, Ti)-C carbides. (A) Zr3C2, Zr6C5, ZrC, Zr5Ti1C6, and Zr4Ti2C6 with different stoichiometric ratios; (B) Zr5Ti1C6, Zr5Ti1C5, Zr5Ti1C4, Zr4Ti2C6, and Zr4Ti2C5 by varying the concentrations of Ti and vacancies.