2. Vavg2 was calculated by using Eq.7, where x1 = 0 and x2 = xmax high possibility that one can select the wrong Li arrangement on the supercell as the minimum energy configuration. That can generate inaccurate voltage profiles and maximum capacities. Recently, alloy-theoretic automated toolkit (ATAT) was used to search the minimum energy ion configurations of the electrodes . ATAT code generates numerous structural candidates for a given composition by adopting an automatic cluster expansion method. Finally, the minimum energy candidates are found with the aid of VASP. In the S4 configuration, the ion on the O/Se surface is located above C atoms, and the other ion is aligned with the nearest Ti atom. According to our calculations S4 is the preferred structure for Ti 2 CSOLi 2 , and that for Ti 2 CSOMg 2 and Ti 2 CSSeLi 2 is S3. S2 was found as the minimum configuration for Ti 2 CSSeMg 2 .