NaMg6Co crystallizes in the orthorhombic Amm2 space group. Na(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Co(1) atoms to form NaMg10Co2 cuboctahedra that share corners with four equivalent Mg(4)Na2Mg10 cuboctahedra, corners with six equivalent Na(1)Mg10Co2 cuboctahedra, edges with two equivalent Mg(4)Na2Mg10 cuboctahedra, faces with two equivalent Na(1)Mg10Co2 cuboctahedra, faces with two equivalent Mg(4)Na2Mg10 cuboctahedra, and faces with six equivalent Mg(2)Mg10Co2 cuboctahedra. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 3-coordinate geometry to two equivalent Na(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and one Co(1) atom. 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 Co(1) atoms to form distorted MgMg10Co2 cuboctahedra that share corners with six equivalent Mg(2)Mg10Co2 cuboctahedra, edges with four equivalent Mg(4)Na2Mg10 cuboctahedra, faces with two equivalent Mg(2)Mg10Co2 cuboctahedra, faces with two equivalent Mg(4)Na2Mg10 cuboctahedra, and faces with six equivalent Na(1)Mg10Co2 cuboctahedra. In the third Mg site, Mg(3) is bonded in a 12-coordinate geometry to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Co(1) atoms. In the fourth Mg site, Mg(4) is bonded to two equivalent Na(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form distorted MgNa2Mg10 cuboctahedra that share corners with four equivalent Na(1)Mg10Co2 cuboctahedra, corners with six equivalent Mg(4)Na2Mg10 cuboctahedra, edges with two equivalent Na(1)Mg10Co2 cuboctahedra, edges with four equivalent Mg(2)Mg10Co2 cuboctahedra, faces with two equivalent Na(1)Mg10Co2 cuboctahedra, faces with two equivalent Mg(2)Mg10Co2 cuboctahedra, and faces with two equivalent Mg(4)Na2Mg10 cuboctahedra. Co(1) is bonded in a 10-coordinate geometry to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), and four equivalent Mg(3) atoms.
NaMg6Co crystallizes in the orthorhombic Amm2 space group. Na(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Co(1) atoms to form NaMg10Co2 cuboctahedra that share corners with four equivalent Mg(4)Na2Mg10 cuboctahedra, corners with six equivalent Na(1)Mg10Co2 cuboctahedra, edges with two equivalent Mg(4)Na2Mg10 cuboctahedra, faces with two equivalent Na(1)Mg10Co2 cuboctahedra, faces with two equivalent Mg(4)Na2Mg10 cuboctahedra, and faces with six equivalent Mg(2)Mg10Co2 cuboctahedra. Both Na(1)-Mg(4) bond lengths are 3.15 Å. All Na(1)-Mg(1) bond lengths are 3.12 Å. There are two shorter (2.96 Å) and two longer (3.29 Å) Na(1)-Mg(3) bond lengths. Both Na(1)-Co(1) bond lengths are 3.31 Å. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 3-coordinate geometry to two equivalent Na(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and one Co(1) atom. There is one shorter (3.08 Å) and one longer (3.17 Å) Mg(1)-Mg(2) bond length. Both Mg(1)-Mg(3) bond lengths are 3.09 Å. Both Mg(1)-Mg(4) bond lengths are 3.05 Å. The Mg(1)-Co(1) bond length is 2.70 Å. 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 Co(1) atoms to form distorted MgMg10Co2 cuboctahedra that share corners with six equivalent Mg(2)Mg10Co2 cuboctahedra, edges with four equivalent Mg(4)Na2Mg10 cuboctahedra, faces with two equivalent Mg(2)Mg10Co2 cuboctahedra, faces with two equivalent Mg(4)Na2Mg10 cuboctahedra, and faces with six equivalent Na(1)Mg10Co2 cuboctahedra. Both Mg(2)-Mg(4) bond lengths are 3.09 Å. All Mg(2)-Mg(3) bond lengths are 3.10 Å. Both Mg(2)-Co(1) bond lengths are 3.17 Å. In the third Mg site, Mg(3) is bonded in a 12-coordinate geometry to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Co(1) atoms. There is one shorter (2.90 Å) and one longer (3.40 Å) Mg(3)-Mg(3) bond length. There is one shorter (3.12 Å) and one longer (3.14 Å) Mg(3)-Mg(4) bond length. Both Mg(3)-Co(1) bond lengths are 2.90 Å. In the fourth Mg site, Mg(4) is bonded to two equivalent Na(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form distorted MgNa2Mg10 cuboctahedra that share corners with four equivalent Na(1)Mg10Co2 cuboctahedra, corners with six equivalent Mg(4)Na2Mg10 cuboctahedra, edges with two equivalent Na(1)Mg10Co2 cuboctahedra, edges with four equivalent Mg(2)Mg10Co2 cuboctahedra, faces with two equivalent Na(1)Mg10Co2 cuboctahedra, faces with two equivalent Mg(2)Mg10Co2 cuboctahedra, and faces with two equivalent Mg(4)Na2Mg10 cuboctahedra. Co(1) is bonded in a 10-coordinate geometry to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), and four equivalent Mg(3) atoms.