In this extended search, we consider compounds from the Inorganic Crystal Structure Database (ICSD), 51 a set augmented by hypothetical phases from the Materials Project database with metastability equal to or less than 30 meV/atom above the stability line (convex hull). For hypothetical compounds, we discard structures where volume changes upon DFT relaxation exceed 20%. Whenever possible, we consider polymorphs of compounds closely matching the structures reported in the ICSD as thermodynamically stable phases. The procedure to identify all possible decomposition reactions and their enthalpies is described in further detail in the section "Bilayer Reactivity from First-principles Calculations".