NaMg7 crystallizes in the hexagonal P-6m2 space group. Na(1) is bonded to six Mg(1,1) and six Mg(2,2) atoms to form NaMg12 cuboctahedra that share corners with six equivalent Na(1)Mg12 cuboctahedra; corners with twelve Mg(1,1)Na2Mg10 cuboctahedra; edges with six Mg(1,1)Na2Mg10 cuboctahedra; edges with twelve Mg(2,2)Na2Mg10 cuboctahedra; faces with two equivalent Na(1)Mg12 cuboctahedra; faces with six equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(1,1)Na2Mg10 cuboctahedra; and faces with six Mg(2,2)Na2Mg10 cuboctahedra. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Na(1); two equivalent Mg(3); four Mg(1,1); and four Mg(2,2) atoms to form distorted MgNa2Mg10 cuboctahedra that share corners with four equivalent Na(1)Mg12 cuboctahedra; corners with fourteen Mg(1,1)Na2Mg10 cuboctahedra; edges with two equivalent Na(1)Mg12 cuboctahedra; edges with four equivalent Mg(3)Mg12 cuboctahedra; edges with four Mg(1,1)Na2Mg10 cuboctahedra; edges with eight Mg(2,2)Na2Mg10 cuboctahedra; faces with two equivalent Na(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(1,1)Na2Mg10 cuboctahedra; and faces with ten Mg(2,2)Na2Mg10 cuboctahedra. In the second Mg site, Mg(1) is bonded to two equivalent Na(1), two equivalent Mg(3), four equivalent Mg(1), and four equivalent Mg(2) atoms to form distorted MgNa2Mg10 cuboctahedra that share corners with four equivalent Na(1)Mg12 cuboctahedra; corners with fourteen Mg(1,1)Na2Mg10 cuboctahedra; edges with two equivalent Na(1)Mg12 cuboctahedra; edges with four equivalent Mg(3)Mg12 cuboctahedra; edges with four equivalent Mg(1)Na2Mg10 cuboctahedra; edges with eight equivalent Mg(2)Na2Mg10 cuboctahedra; faces with two equivalent Na(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(1,1)Na2Mg10 cuboctahedra; and faces with ten Mg(2,2)Na2Mg10 cuboctahedra. In the third Mg site, Mg(2) is bonded to two equivalent Na(1), two equivalent Mg(3), four equivalent Mg(1), and four equivalent Mg(2) atoms to form MgNa2Mg10 cuboctahedra that share corners with four equivalent Mg(3)Mg12 cuboctahedra; corners with fourteen Mg(2,2)Na2Mg10 cuboctahedra; edges with two equivalent Mg(3)Mg12 cuboctahedra; edges with four equivalent Na(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Na2Mg10 cuboctahedra; edges with eight equivalent Mg(1)Na2Mg10 cuboctahedra; faces with two equivalent Na(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(2,2)Na2Mg10 cuboctahedra; and faces with ten Mg(1,1)Na2Mg10 cuboctahedra. In the fourth Mg site, Mg(2) is bonded to two equivalent Na(1); two equivalent Mg(3); four Mg(1,1); and four Mg(2,2) atoms to form MgNa2Mg10 cuboctahedra that share corners with four equivalent Mg(3)Mg12 cuboctahedra; corners with fourteen Mg(2,2)Na2Mg10 cuboctahedra; edges with two equivalent Mg(3)Mg12 cuboctahedra; edges with four equivalent Na(1)Mg12 cuboctahedra; edges with four Mg(2,2)Na2Mg10 cuboctahedra; edges with eight Mg(1,1)Na2Mg10 cuboctahedra; faces with two equivalent Na(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(2,2)Na2Mg10 cuboctahedra; and faces with ten Mg(1,1)Na2Mg10 cuboctahedra. In the fifth Mg site, Mg(3) is bonded to six Mg(1,1) and six Mg(2,2) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(3)Mg12 cuboctahedra; corners with twelve Mg(2,2)Na2Mg10 cuboctahedra; edges with six Mg(2,2)Na2Mg10 cuboctahedra; edges with twelve Mg(1,1)Na2Mg10 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six equivalent Na(1)Mg12 cuboctahedra; faces with six Mg(1,1)Na2Mg10 cuboctahedra; and faces with six Mg(2,2)Na2Mg10 cuboctahedra.
NaMg7 crystallizes in the hexagonal P-6m2 space group. Na(1) is bonded to six Mg(1,1) and six Mg(2,2) atoms to form NaMg12 cuboctahedra that share corners with six equivalent Na(1)Mg12 cuboctahedra; corners with twelve Mg(1,1)Na2Mg10 cuboctahedra; edges with six Mg(1,1)Na2Mg10 cuboctahedra; edges with twelve Mg(2,2)Na2Mg10 cuboctahedra; faces with two equivalent Na(1)Mg12 cuboctahedra; faces with six equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(1,1)Na2Mg10 cuboctahedra; and faces with six Mg(2,2)Na2Mg10 cuboctahedra. All Na(1)-Mg(1,1) bond lengths are 3.23 Å. All Na(1)-Mg(2,2) bond lengths are 3.24 Å. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Na(1); two equivalent Mg(3); four Mg(1,1); and four Mg(2,2) atoms to form distorted MgNa2Mg10 cuboctahedra that share corners with four equivalent Na(1)Mg12 cuboctahedra; corners with fourteen Mg(1,1)Na2Mg10 cuboctahedra; edges with two equivalent Na(1)Mg12 cuboctahedra; edges with four equivalent Mg(3)Mg12 cuboctahedra; edges with four Mg(1,1)Na2Mg10 cuboctahedra; edges with eight Mg(2,2)Na2Mg10 cuboctahedra; faces with two equivalent Na(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(1,1)Na2Mg10 cuboctahedra; and faces with ten Mg(2,2)Na2Mg10 cuboctahedra. Both Mg(1)-Mg(3) bond lengths are 3.24 Å. There are two shorter (3.22 Å) and two longer (3.23 Å) Mg(1)-Mg(1,1) bond lengths. All Mg(1)-Mg(2,2) bond lengths are 3.24 Å. In the second Mg site, Mg(1) is bonded to two equivalent Na(1), two equivalent Mg(3), four equivalent Mg(1), and four equivalent Mg(2) atoms to form distorted MgNa2Mg10 cuboctahedra that share corners with four equivalent Na(1)Mg12 cuboctahedra; corners with fourteen Mg(1,1)Na2Mg10 cuboctahedra; edges with two equivalent Na(1)Mg12 cuboctahedra; edges with four equivalent Mg(3)Mg12 cuboctahedra; edges with four equivalent Mg(1)Na2Mg10 cuboctahedra; edges with eight equivalent Mg(2)Na2Mg10 cuboctahedra; faces with two equivalent Na(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(1,1)Na2Mg10 cuboctahedra; and faces with ten Mg(2,2)Na2Mg10 cuboctahedra. Both Mg(1)-Mg(3) bond lengths are 3.24 Å. All Mg(1)-Mg(2) bond lengths are 3.24 Å. In the third Mg site, Mg(2) is bonded to two equivalent Na(1), two equivalent Mg(3), four equivalent Mg(1), and four equivalent Mg(2) atoms to form MgNa2Mg10 cuboctahedra that share corners with four equivalent Mg(3)Mg12 cuboctahedra; corners with fourteen Mg(2,2)Na2Mg10 cuboctahedra; edges with two equivalent Mg(3)Mg12 cuboctahedra; edges with four equivalent Na(1)Mg12 cuboctahedra; edges with four equivalent Mg(2)Na2Mg10 cuboctahedra; edges with eight equivalent Mg(1)Na2Mg10 cuboctahedra; faces with two equivalent Na(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(2,2)Na2Mg10 cuboctahedra; and faces with ten Mg(1,1)Na2Mg10 cuboctahedra. Both Mg(2)-Mg(3) bond lengths are 3.23 Å. There are two shorter (3.21 Å) and two longer (3.24 Å) Mg(2)-Mg(2) bond lengths. In the fourth Mg site, Mg(2) is bonded to two equivalent Na(1); two equivalent Mg(3); four Mg(1,1); and four Mg(2,2) atoms to form MgNa2Mg10 cuboctahedra that share corners with four equivalent Mg(3)Mg12 cuboctahedra; corners with fourteen Mg(2,2)Na2Mg10 cuboctahedra; edges with two equivalent Mg(3)Mg12 cuboctahedra; edges with four equivalent Na(1)Mg12 cuboctahedra; edges with four Mg(2,2)Na2Mg10 cuboctahedra; edges with eight Mg(1,1)Na2Mg10 cuboctahedra; faces with two equivalent Na(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six Mg(2,2)Na2Mg10 cuboctahedra; and faces with ten Mg(1,1)Na2Mg10 cuboctahedra. Both Mg(2)-Mg(3) bond lengths are 3.23 Å. There is one shorter (3.21 Å) and one longer (3.24 Å) Mg(2)-Mg(2) bond length. In the fifth Mg site, Mg(3) is bonded to six Mg(1,1) and six Mg(2,2) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(3)Mg12 cuboctahedra; corners with twelve Mg(2,2)Na2Mg10 cuboctahedra; edges with six Mg(2,2)Na2Mg10 cuboctahedra; edges with twelve Mg(1,1)Na2Mg10 cuboctahedra; faces with two equivalent Mg(3)Mg12 cuboctahedra; faces with six equivalent Na(1)Mg12 cuboctahedra; faces with six Mg(1,1)Na2Mg10 cuboctahedra; and faces with six Mg(2,2)Na2Mg10 cuboctahedra.