KMg6Y crystallizes in the orthorhombic Amm2 space group. K(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Y(1) atoms to form KY2Mg10 cuboctahedra that share corners with four equivalent Mg(4)K2Mg10 cuboctahedra, corners with six equivalent K(1)Y2Mg10 cuboctahedra, edges with two equivalent Mg(4)K2Mg10 cuboctahedra, edges with four equivalent Y(1)K2Mg10 cuboctahedra, faces with two equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Y(1)K2Mg10 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 K(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)K2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y2Mg10 cuboctahedra, edges with two equivalent Y(1)K2Mg10 cuboctahedra, edges with four equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)K2Mg10 cuboctahedra, and faces with six equivalent K(1)Y2Mg10 cuboctahedra. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to two equivalent K(1), 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 K(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form distorted MgK2Mg10 cuboctahedra that share corners with four equivalent K(1)Y2Mg10 cuboctahedra, corners with six equivalent Mg(4)K2Mg10 cuboctahedra, edges with two equivalent K(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, and faces with six equivalent Y(1)K2Mg10 cuboctahedra. Y(1) is bonded to two equivalent K(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form YK2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)K2Mg10 cuboctahedra, edges with two equivalent Mg(2)Y2Mg10 cuboctahedra, edges with four equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)K2Mg10 cuboctahedra, and faces with six equivalent Mg(4)K2Mg10 cuboctahedra.
KMg6Y crystallizes in the orthorhombic Amm2 space group. K(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Y(1) atoms to form KY2Mg10 cuboctahedra that share corners with four equivalent Mg(4)K2Mg10 cuboctahedra, corners with six equivalent K(1)Y2Mg10 cuboctahedra, edges with two equivalent Mg(4)K2Mg10 cuboctahedra, edges with four equivalent Y(1)K2Mg10 cuboctahedra, faces with two equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Y(1)K2Mg10 cuboctahedra, and faces with six equivalent Mg(2)Y2Mg10 cuboctahedra. Both K(1)-Mg(4) bond lengths are 3.49 Å. All K(1)-Mg(1) bond lengths are 3.36 Å. There are two shorter (3.33 Å) and two longer (3.51 Å) K(1)-Mg(3) bond lengths. Both K(1)-Y(1) bond lengths are 3.56 Å. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 11-coordinate geometry to two equivalent K(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 3.27 Å. There is one shorter (3.39 Å) and one longer (3.45 Å) Mg(1)-Mg(2) bond length. Both Mg(1)-Mg(3) bond lengths are 3.39 Å. Both Mg(1)-Mg(4) bond lengths are 3.30 Å. There is one shorter (3.25 Å) and one longer (3.58 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)K2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y2Mg10 cuboctahedra, edges with two equivalent Y(1)K2Mg10 cuboctahedra, edges with four equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)K2Mg10 cuboctahedra, and faces with six equivalent K(1)Y2Mg10 cuboctahedra. Both Mg(2)-Mg(4) bond lengths are 3.41 Å. All Mg(2)-Mg(3) bond lengths are 3.33 Å. Both Mg(2)-Y(1) bond lengths are 3.48 Å. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to two equivalent K(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), and two equivalent Y(1) atoms. There is one shorter (3.39 Å) and one longer (3.45 Å) Mg(3)-Mg(4) bond length. Both Mg(3)-Y(1) bond lengths are 3.27 Å. In the fourth Mg site, Mg(4) is bonded to two equivalent K(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form distorted MgK2Mg10 cuboctahedra that share corners with four equivalent K(1)Y2Mg10 cuboctahedra, corners with six equivalent Mg(4)K2Mg10 cuboctahedra, edges with two equivalent K(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)K2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, and faces with six equivalent Y(1)K2Mg10 cuboctahedra. Y(1) is bonded to two equivalent K(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form YK2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)K2Mg10 cuboctahedra, edges with two equivalent Mg(2)Y2Mg10 cuboctahedra, edges with four equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent K(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)K2Mg10 cuboctahedra, and faces with six equivalent Mg(4)K2Mg10 cuboctahedra.