RbCu3SiSe4 crystallizes in the cubic P-43m space group. Rb(1) is bonded to four equivalent Se(1) atoms to form RbSe4 tetrahedra that share corners with four equivalent Si(1)Se4 tetrahedra and corners with twelve equivalent Cu(1)Se4 tetrahedra. Cu(1) is bonded to four equivalent Se(1) atoms to form distorted CuSe4 tetrahedra that share corners with four equivalent Rb(1)Se4 tetrahedra, corners with eight equivalent Cu(1)Se4 tetrahedra, and edges with two equivalent Si(1)Se4 tetrahedra. Si(1) is bonded to four equivalent Se(1) atoms to form SiSe4 tetrahedra that share corners with four equivalent Rb(1)Se4 tetrahedra and edges with six equivalent Cu(1)Se4 tetrahedra. Se(1) is bonded to one Rb(1), three equivalent Cu(1), and one Si(1) atom to form a mixture of corner and edge-sharing SeRbCu3Si trigonal bipyramids.
RbCu3SiSe4 crystallizes in the cubic P-43m space group. Rb(1) is bonded to four equivalent Se(1) atoms to form RbSe4 tetrahedra that share corners with four equivalent Si(1)Se4 tetrahedra and corners with twelve equivalent Cu(1)Se4 tetrahedra. All Rb(1)-Se(1) bond lengths are 3.13 Å. Cu(1) is bonded to four equivalent Se(1) atoms to form distorted CuSe4 tetrahedra that share corners with four equivalent Rb(1)Se4 tetrahedra, corners with eight equivalent Cu(1)Se4 tetrahedra, and edges with two equivalent Si(1)Se4 tetrahedra. All Cu(1)-Se(1) bond lengths are 2.59 Å. Si(1) is bonded to four equivalent Se(1) atoms to form SiSe4 tetrahedra that share corners with four equivalent Rb(1)Se4 tetrahedra and edges with six equivalent Cu(1)Se4 tetrahedra. All Si(1)-Se(1) bond lengths are 2.26 Å. Se(1) is bonded to one Rb(1), three equivalent Cu(1), and one Si(1) atom to form a mixture of corner and edge-sharing SeRbCu3Si trigonal bipyramids.