BaMg6Y crystallizes in the orthorhombic Amm2 space group. Ba(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Y(1) atoms to form BaY2Mg10 cuboctahedra that share corners with four equivalent Mg(4)Ba2Mg10 cuboctahedra, corners with six equivalent Ba(1)Y2Mg10 cuboctahedra, edges with two equivalent Mg(4)Ba2Mg10 cuboctahedra, edges with four equivalent Y(1)Ba2Mg10 cuboctahedra, faces with two equivalent Ba(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)Ba2Mg10 cuboctahedra, faces with two equivalent Y(1)Ba2Mg10 cuboctahedra, and faces with six equivalent Mg(2)Y2Mg10 cuboctahedra. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 11-coordinate geometry to two equivalent Ba(1), one Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Y(1) atoms. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with four equivalent Y(1)Ba2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y2Mg10 cuboctahedra, edges with two equivalent Y(1)Ba2Mg10 cuboctahedra, edges with four equivalent Mg(4)Ba2Mg10 cuboctahedra, faces with two equivalent Mg(4)Ba2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Ba2Mg10 cuboctahedra, and faces with six equivalent Ba(1)Y2Mg10 cuboctahedra. In the third Mg site, Mg(3) is bonded in a 11-coordinate geometry to two equivalent Ba(1), one Mg(3), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), and two equivalent Y(1) atoms. In the fourth Mg site, Mg(4) is bonded to two equivalent Ba(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form distorted MgBa2Mg10 cuboctahedra that share corners with four equivalent Ba(1)Y2Mg10 cuboctahedra, corners with six equivalent Mg(4)Ba2Mg10 cuboctahedra, edges with two equivalent Ba(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Ba(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)Ba2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, and faces with six equivalent Y(1)Ba2Mg10 cuboctahedra. Y(1) is bonded to two equivalent Ba(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form YBa2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Ba2Mg10 cuboctahedra, edges with two equivalent Mg(2)Y2Mg10 cuboctahedra, edges with four equivalent Ba(1)Y2Mg10 cuboctahedra, faces with two equivalent Ba(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Ba2Mg10 cuboctahedra, and faces with six equivalent Mg(4)Ba2Mg10 cuboctahedra.
BaMg6Y crystallizes in the orthorhombic Amm2 space group. Ba(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Y(1) atoms to form BaY2Mg10 cuboctahedra that share corners with four equivalent Mg(4)Ba2Mg10 cuboctahedra, corners with six equivalent Ba(1)Y2Mg10 cuboctahedra, edges with two equivalent Mg(4)Ba2Mg10 cuboctahedra, edges with four equivalent Y(1)Ba2Mg10 cuboctahedra, faces with two equivalent Ba(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)Ba2Mg10 cuboctahedra, faces with two equivalent Y(1)Ba2Mg10 cuboctahedra, and faces with six equivalent Mg(2)Y2Mg10 cuboctahedra. Both Ba(1)-Mg(4) bond lengths are 3.54 Å. All Ba(1)-Mg(1) bond lengths are 3.39 Å. There are two shorter (3.39 Å) and two longer (3.47 Å) Ba(1)-Mg(3) bond lengths. Both Ba(1)-Y(1) bond lengths are 3.54 Å. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 11-coordinate geometry to two equivalent Ba(1), one Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Y(1) atoms. The Mg(1)-Mg(1) bond length is 3.41 Å. There is one shorter (3.40 Å) and one longer (3.46 Å) Mg(1)-Mg(2) bond length. Both Mg(1)-Mg(3) bond lengths are 3.38 Å. Both Mg(1)-Mg(4) bond lengths are 3.35 Å. There is one shorter (3.25 Å) and one longer (3.61 Å) Mg(1)-Y(1) bond length. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with four equivalent Y(1)Ba2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y2Mg10 cuboctahedra, edges with two equivalent Y(1)Ba2Mg10 cuboctahedra, edges with four equivalent Mg(4)Ba2Mg10 cuboctahedra, faces with two equivalent Mg(4)Ba2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Ba2Mg10 cuboctahedra, and faces with six equivalent Ba(1)Y2Mg10 cuboctahedra. Both Mg(2)-Mg(4) bond lengths are 3.41 Å. All Mg(2)-Mg(3) bond lengths are 3.40 Å. Both Mg(2)-Y(1) bond lengths are 3.54 Å. In the third Mg site, Mg(3) is bonded in a 11-coordinate geometry to two equivalent Ba(1), one Mg(3), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), and two equivalent Y(1) atoms. The Mg(3)-Mg(3) bond length is 3.41 Å. There is one shorter (3.41 Å) and one longer (3.45 Å) Mg(3)-Mg(4) bond length. Both Mg(3)-Y(1) bond lengths are 3.31 Å. In the fourth Mg site, Mg(4) is bonded to two equivalent Ba(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form distorted MgBa2Mg10 cuboctahedra that share corners with four equivalent Ba(1)Y2Mg10 cuboctahedra, corners with six equivalent Mg(4)Ba2Mg10 cuboctahedra, edges with two equivalent Ba(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Ba(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)Ba2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, and faces with six equivalent Y(1)Ba2Mg10 cuboctahedra. Y(1) is bonded to two equivalent Ba(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form YBa2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Ba2Mg10 cuboctahedra, edges with two equivalent Mg(2)Y2Mg10 cuboctahedra, edges with four equivalent Ba(1)Y2Mg10 cuboctahedra, faces with two equivalent Ba(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Ba2Mg10 cuboctahedra, and faces with six equivalent Mg(4)Ba2Mg10 cuboctahedra.