CsMg6Y is Bergman Structure: Mg32(Al,Zn)49 Bergman-like structured and crystallizes in the orthorhombic Amm2 space group. Cs(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Y(1) atoms to form distorted CsY2Mg10 cuboctahedra that share corners with six equivalent Cs(1)Y2Mg10 cuboctahedra, edges with four equivalent Y(1)Cs2Mg10 cuboctahedra, faces with two equivalent Cs(1)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Cs2Mg10 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 Cs(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 distorted MgY2Mg10 cuboctahedra that share corners with four equivalent Y(1)Cs2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y2Mg10 cuboctahedra, edges with two equivalent Y(1)Cs2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Cs2Mg10 cuboctahedra, and faces with six equivalent Cs(1)Y2Mg10 cuboctahedra. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to two equivalent Cs(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 in a 12-coordinate geometry to two equivalent Cs(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms. Y(1) is bonded to two equivalent Cs(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form YCs2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Cs2Mg10 cuboctahedra, edges with two equivalent Mg(2)Y2Mg10 cuboctahedra, edges with four equivalent Cs(1)Y2Mg10 cuboctahedra, faces with two equivalent Cs(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, and faces with two equivalent Y(1)Cs2Mg10 cuboctahedra.
CsMg6Y is Bergman Structure: Mg32(Al,Zn)49 Bergman-like structured and crystallizes in the orthorhombic Amm2 space group. Cs(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Y(1) atoms to form distorted CsY2Mg10 cuboctahedra that share corners with six equivalent Cs(1)Y2Mg10 cuboctahedra, edges with four equivalent Y(1)Cs2Mg10 cuboctahedra, faces with two equivalent Cs(1)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Cs2Mg10 cuboctahedra, and faces with six equivalent Mg(2)Y2Mg10 cuboctahedra. Both Cs(1)-Mg(4) bond lengths are 3.60 Å. All Cs(1)-Mg(1) bond lengths are 3.48 Å. There are two shorter (3.39 Å) and two longer (3.56 Å) Cs(1)-Mg(3) bond lengths. Both Cs(1)-Y(1) bond lengths are 3.62 Å. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 11-coordinate geometry to two equivalent Cs(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 3.12 Å. There is one shorter (3.42 Å) and one longer (3.54 Å) Mg(1)-Mg(2) bond length. Both Mg(1)-Mg(3) bond lengths are 3.44 Å. Both Mg(1)-Mg(4) bond lengths are 3.29 Å. There is one shorter (3.25 Å) and one longer (3.71 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 distorted MgY2Mg10 cuboctahedra that share corners with four equivalent Y(1)Cs2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y2Mg10 cuboctahedra, edges with two equivalent Y(1)Cs2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Cs2Mg10 cuboctahedra, and faces with six equivalent Cs(1)Y2Mg10 cuboctahedra. Both Mg(2)-Mg(4) bond lengths are 3.42 Å. All Mg(2)-Mg(3) bond lengths are 3.43 Å. Both Mg(2)-Y(1) bond lengths are 3.60 Å. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to two equivalent Cs(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), and two equivalent Y(1) atoms. There is one shorter (3.45 Å) and one longer (3.50 Å) Mg(3)-Mg(4) bond length. Both Mg(3)-Y(1) bond lengths are 3.30 Å. In the fourth Mg site, Mg(4) is bonded in a 12-coordinate geometry to two equivalent Cs(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms. Y(1) is bonded to two equivalent Cs(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form YCs2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Cs2Mg10 cuboctahedra, edges with two equivalent Mg(2)Y2Mg10 cuboctahedra, edges with four equivalent Cs(1)Y2Mg10 cuboctahedra, faces with two equivalent Cs(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, and faces with two equivalent Y(1)Cs2Mg10 cuboctahedra.