Li 3 Tr As 2 ( Tr =Al, Ga, In) – Derivatives of the antifluorite type structure, conductivities and electronic structures

Li 3 AlAs 2 , Li 3 GaAs 2 and Li 3 InAs 2 were obtained from the elements via high temperature synthesis. Li 3 AlAs 2 and Li 3 GaAs 2 crystallize in a distorted 2 ⋅ 2 ⋅ 1 superstructure of the antifluorite structure type. The orthorhombic crystal structure is isotypic to Li 3 AlP 2 and Li 3 GaP 2 , space group Cmce (No. 64) showing layers of condensed Tr As 4 ‐tetrahedra ( Tr= Al, Ga). Li 3 InAs 2 crystallizes isotypic to Li 3 InP 2 in a distorted 2 ⋅ 2 ⋅ 4 antifluorite type superstructure. The crystal structure is tetragonal, space group I4 1 /acd (No. 142), showing a 3D‐network of In 4 As 10 ‐supertetrahedra. Structural characterization by powder X‐ray diffraction, thermal analysis, conductivity measurements and band structure calculations show ion conductivity for Li 3 InAs 2 and electronic charge transport for Li 3 AlAs 2 and Li 3 GaAs 2 .