Rb2WSe4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 9-coordinate geometry to two equivalent Se(3), three equivalent Se(2), and four equivalent Se(1) atoms. In the second Rb site, Rb(2) is bonded in a 8-coordinate geometry to two equivalent Se(2), two equivalent Se(3), and four equivalent Se(1) atoms. W(1) is bonded in a tetrahedral geometry to one Se(2), one Se(3), and two equivalent Se(1) atoms. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), and one W(1) atom. In the second Se site, Se(2) is bonded to two equivalent Rb(2), three equivalent Rb(1), and one W(1) atom to form distorted SeRb5W octahedra that share corners with four equivalent Se(2)Rb5W octahedra,  a cornercorner with one Se(3)Rb4W square pyramid, edges with two equivalent Se(2)Rb5W octahedra, and edges with five equivalent Se(3)Rb4W square pyramids. The corner-sharing octahedral tilt angles range from 21-69°. In the third Se site, Se(3) is bonded to two equivalent Rb(1), two equivalent Rb(2), and one W(1) atom to form distorted SeRb4W square pyramids that share  a cornercorner with one Se(2)Rb5W octahedra, corners with four equivalent Se(3)Rb4W square pyramids, and edges with five equivalent Se(2)Rb5W octahedra. The corner-sharing octahedral tilt angles are 18°.
Rb2WSe4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 9-coordinate geometry to two equivalent Se(3), three equivalent Se(2), and four equivalent Se(1) atoms. There is one shorter (3.41 Å) and one longer (3.49 Å) Rb(1)-Se(3) bond length. There is one shorter (3.60 Å) and two longer (3.73 Å) Rb(1)-Se(2) bond lengths. There are two shorter (3.58 Å) and two longer (3.74 Å) Rb(1)-Se(1) bond lengths. In the second Rb site, Rb(2) is bonded in a 8-coordinate geometry to two equivalent Se(2), two equivalent Se(3), and four equivalent Se(1) atoms. There is one shorter (3.74 Å) and one longer (3.83 Å) Rb(2)-Se(2) bond length. Both Rb(2)-Se(3) bond lengths are 3.72 Å. There are two shorter (3.67 Å) and two longer (3.74 Å) Rb(2)-Se(1) bond lengths. W(1) is bonded in a tetrahedral geometry to one Se(2), one Se(3), and two equivalent Se(1) atoms. The W(1)-Se(2) bond length is 2.33 Å. The W(1)-Se(3) bond length is 2.32 Å. Both W(1)-Se(1) bond lengths are 2.31 Å. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), and one W(1) atom. In the second Se site, Se(2) is bonded to two equivalent Rb(2), three equivalent Rb(1), and one W(1) atom to form distorted SeRb5W octahedra that share corners with four equivalent Se(2)Rb5W octahedra,  a cornercorner with one Se(3)Rb4W square pyramid, edges with two equivalent Se(2)Rb5W octahedra, and edges with five equivalent Se(3)Rb4W square pyramids. The corner-sharing octahedral tilt angles range from 21-69°. In the third Se site, Se(3) is bonded to two equivalent Rb(1), two equivalent Rb(2), and one W(1) atom to form distorted SeRb4W square pyramids that share  a cornercorner with one Se(2)Rb5W octahedra, corners with four equivalent Se(3)Rb4W square pyramids, and edges with five equivalent Se(2)Rb5W octahedra. The corner-sharing octahedral tilt angles are 18°.