Li_0.5Al_0.5Mg₂(MoO₄)₃

The title compound, lithium/aluminium dimagnesium tetra­kis­[orthomolybdate(VI)], was prepared by a solid-state reaction route. The crystal structure is built up from MgO₆ octa­hedra and MoO₄ tetra­hedra sharing corners and edges, forming two types of chains running along [100]. These chains are linked into layers parallel to (010) and finally linked by MoO₄ tetra­hedra into a three-dimensional framework structure with channels parallel to [001] in which lithium and aluminium cations equally occupy the same position within a distorted trigonal-bipyramidal coordination environment. The title structure is isotypic with LiMgIn(MoO₄)₃, with the In site becoming an Mg site and the fully occupied Li site a statistically occupied Li/Al site in the title structure.