Na2Mg(BiO3)2 is Orthorhombic Perovskite-derived structured and crystallizes in the trigonal R-3 space group. Na(1) is bonded in a 6-coordinate geometry to six equivalent O(1) atoms. Mg(1) is bonded to six equivalent O(1) atoms to form MgO6 octahedra that share corners with six equivalent Bi(1)O6 octahedra and faces with two equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles are 36°. Bi(1) is bonded to six equivalent O(1) atoms to form distorted BiO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra, edges with three equivalent Bi(1)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles are 36°. O(1) is bonded in a 5-coordinate geometry to two equivalent Na(1), one Mg(1), and two equivalent Bi(1) atoms.
Na2Mg(BiO3)2 is Orthorhombic Perovskite-derived structured and crystallizes in the trigonal R-3 space group. Na(1) is bonded in a 6-coordinate geometry to six equivalent O(1) atoms. There are three shorter (2.36 Å) and three longer (2.89 Å) Na(1)-O(1) bond lengths. Mg(1) is bonded to six equivalent O(1) atoms to form MgO6 octahedra that share corners with six equivalent Bi(1)O6 octahedra and faces with two equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles are 36°. All Mg(1)-O(1) bond lengths are 2.16 Å. Bi(1) is bonded to six equivalent O(1) atoms to form distorted BiO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra, edges with three equivalent Bi(1)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles are 36°. There are three shorter (2.25 Å) and three longer (2.32 Å) Bi(1)-O(1) bond lengths. O(1) is bonded in a 5-coordinate geometry to two equivalent Na(1), one Mg(1), and two equivalent Bi(1) atoms.