Material design of indium based compounds: possible candidates for charge, valence, and bond disproportionation and superconductivity

We design and investigate the physical properties of new indium compounds AInX${}_3$ (A = alkali metals, X = F or Cl). We find nine new In based materials in their ground state and are thermodynamically stable but are not reported in ICSD (Inorganic Crystal Structure Database). We also discuss several metastable structures. This new series of materials display multiple valences, charge and bond disproportionation, and dimerization. The most common valence of In is 3+. We also find two rare alternatives, one has In${}^{2+}$ with In-In dimerization and the other shows valence disproportionation to In${}^{1+}$ and In${}^{3+}$ with bond disproportionation. We study the possibility of superconductivity in these new In compounds and find that CsInF${}_3$ has a transition temperature about 24 K with sufficient hole doping and pressure.