Dirubidium digallium oxide bis­(ortho­borate)

The title compound, Rb2Ga2O(BO3)2, is part of the homologous series A 2Ga2O(BO3)2 (A = Na, K, Rb and Cs). The structure contains pairs of gallium-centered tetra­hedra connected through a shared oxygen vertex. Orthoborate triangles connect the basal vertices of the tetra­hedra, forming a three-dimensional network with voids occupied by rubidium ions