This calculation also allows for the determination of the average voltage associated with intercalation, which is crucial for energy material applications. Additionally, by replacing Etot(Host) with ΣEtot(Host-elements), where Etot(Host-elements) represents the total energy of the standard state of element constructing the host, eq. 1 becomes the formation energy (Ef) of the layered intercalation compounds. A negative Ef value suggests that the reaction may proceed from the standard state of elements. In addition to Eint, Ef is also shown in Supporting Information.