NaMg6Si crystallizes in the orthorhombic Amm2 space group. Na(1) is bonded to two equivalent Mg(4); four Mg(1,1,1); four equivalent Mg(2); and two equivalent Si(1) atoms to form NaMg10Si2 cuboctahedra that share corners with four equivalent Si(1)Na2Mg10 cuboctahedra; corners with six equivalent Na(1)Mg10Si2 cuboctahedra; corners with eight Mg(1,1,1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Si(1)Na2Mg10 cuboctahedra; edges with four equivalent Mg(4)Na2Mg10 cuboctahedra; edges with four Mg(1,1,1)Na2Mg8Si2 cuboctahedra; edges with eight Mg(2,2)Na2Mg8Si2 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four Mg(1,1,1)Na2Mg8Si2 cuboctahedra; faces with four equivalent Mg(2)Na2Mg8Si2 cuboctahedra; and faces with six equivalent Mg(3)Mg10Si2 cuboctahedra. There are seven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Si(1) atoms to form distorted MgNa2Mg8Si2 cuboctahedra that share corners with four equivalent Na(1)Mg10Si2 cuboctahedra; corners with four equivalent Si(1)Na2Mg10 cuboctahedra; corners with ten Mg(1,1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Na(1)Mg10Si2 cuboctahedra; edges with two equivalent Mg(1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Si(1)Na2Mg10 cuboctahedra; edges with four equivalent Mg(3)Mg10Si2 cuboctahedra; edges with four equivalent Mg(4)Na2Mg10 cuboctahedra; edges with four equivalent Mg(2)Na2Mg8Si2 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four Mg(1,1)Na2Mg8Si2 cuboctahedra; and faces with eight Mg(2,2)Na2Mg8Si2 cuboctahedra. In the second Mg site, Mg(1) is bonded to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Si(1) atoms to form distorted MgNa2Mg8Si2 cuboctahedra that share corners with four equivalent Na(1)Mg10Si2 cuboctahedra; corners with four equivalent Si(1)Na2Mg10 cuboctahedra; corners with ten Mg(1,1,1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Na(1)Mg10Si2 cuboctahedra; edges with two equivalent Mg(1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Si(1)Na2Mg10 cuboctahedra; edges with four equivalent Mg(3)Mg10Si2 cuboctahedra; edges with four equivalent Mg(4)Na2Mg10 cuboctahedra; edges with four equivalent Mg(2)Na2Mg8Si2 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four Mg(1,1)Na2Mg8Si2 cuboctahedra; and faces with eight Mg(2,2)Na2Mg8Si2 cuboctahedra. In the third Mg site, Mg(2) is bonded to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Si(1) atoms to form distorted MgNa2Mg8Si2 cuboctahedra that share corners with four equivalent Mg(3)Mg10Si2 cuboctahedra; corners with four equivalent Mg(4)Na2Mg10 cuboctahedra; corners with ten Mg(2,2)Na2Mg8Si2 cuboctahedra; edges with two equivalent Mg(3)Mg10Si2 cuboctahedra; edges with two equivalent Mg(4)Na2Mg10 cuboctahedra; edges with two equivalent Mg(2)Na2Mg8Si2 cuboctahedra; edges with four equivalent Na(1)Mg10Si2 cuboctahedra; edges with four equivalent Mg(1)Na2Mg8Si2 cuboctahedra; edges with four equivalent Si(1)Na2Mg10 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four equivalent Mg(2)Na2Mg8Si2 cuboctahedra; and faces with eight Mg(1,1)Na2Mg8Si2 cuboctahedra. In the fourth Mg site, Mg(3) is bonded to two equivalent Mg(4); four Mg(1,1); four Mg(2,2); and two equivalent Si(1) atoms to form distorted MgMg10Si2 cuboctahedra that share corners with four equivalent Mg(4)Na2Mg10 cuboctahedra; corners with six equivalent Mg(3)Mg10Si2 cuboctahedra; corners with eight Mg(2,2)Na2Mg8Si2 cuboctahedra; edges with two equivalent Mg(4)Na2Mg10 cuboctahedra; edges with four Mg(2,2)Na2Mg8Si2 cuboctahedra; edges with four equivalent Si(1)Na2Mg10 cuboctahedra; edges with eight Mg(1,1,1)Na2Mg8Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four Mg(1,1)Na2Mg8Si2 cuboctahedra; faces with four Mg(2,2)Na2Mg8Si2 cuboctahedra; and faces with six equivalent Na(1)Mg10Si2 cuboctahedra. In the fifth Mg site, Mg(4) 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 Mg(3)Mg10Si2 cuboctahedra; corners with six equivalent Mg(4)Na2Mg10 cuboctahedra; corners with eight Mg(2,2)Na2Mg8Si2 cuboctahedra; edges with two equivalent Mg(3)Mg10Si2 cuboctahedra; edges with four equivalent Na(1)Mg10Si2 cuboctahedra; edges with four Mg(2,2)Na2Mg8Si2 cuboctahedra; edges with eight Mg(1,1,1)Na2Mg8Si2 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with four Mg(1,1)Na2Mg8Si2 cuboctahedra; faces with four Mg(2,2)Na2Mg8Si2 cuboctahedra; and faces with six equivalent Si(1)Na2Mg10 cuboctahedra. In the sixth Mg site, Mg(1) is bonded to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Si(1) atoms to form distorted MgNa2Mg8Si2 cuboctahedra that share corners with four equivalent Na(1)Mg10Si2 cuboctahedra; corners with four equivalent Si(1)Na2Mg10 cuboctahedra; corners with ten Mg(1,1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Na(1)Mg10Si2 cuboctahedra; edges with two equivalent Mg(1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Si(1)Na2Mg10 cuboctahedra; edges with four equivalent Mg(3)Mg10Si2 cuboctahedra; edges with four equivalent Mg(4)Na2Mg10 cuboctahedra; edges with four equivalent Mg(2)Na2Mg8Si2 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four Mg(1,1)Na2Mg8Si2 cuboctahedra; and faces with eight Mg(2,2)Na2Mg8Si2 cuboctahedra. In the seventh Mg site, Mg(2) is bonded to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Si(1) atoms to form distorted MgNa2Mg8Si2 cuboctahedra that share corners with four equivalent Mg(3)Mg10Si2 cuboctahedra; corners with four equivalent Mg(4)Na2Mg10 cuboctahedra; corners with ten Mg(2,2)Na2Mg8Si2 cuboctahedra; edges with two equivalent Mg(3)Mg10Si2 cuboctahedra; edges with two equivalent Mg(4)Na2Mg10 cuboctahedra; edges with two equivalent Mg(2)Na2Mg8Si2 cuboctahedra; edges with four equivalent Na(1)Mg10Si2 cuboctahedra; edges with four equivalent Mg(1)Na2Mg8Si2 cuboctahedra; edges with four equivalent Si(1)Na2Mg10 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four Mg(2,2)Na2Mg8Si2 cuboctahedra; and faces with eight Mg(1,1,1)Na2Mg8Si2 cuboctahedra. Si(1) is bonded to two equivalent Na(1); two equivalent Mg(3); four Mg(1,1,1); and four equivalent Mg(2) atoms to form SiNa2Mg10 cuboctahedra that share corners with four equivalent Na(1)Mg10Si2 cuboctahedra; corners with six equivalent Si(1)Na2Mg10 cuboctahedra; corners with eight Mg(1,1,1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Na(1)Mg10Si2 cuboctahedra; edges with four equivalent Mg(3)Mg10Si2 cuboctahedra; edges with four Mg(1,1,1)Na2Mg8Si2 cuboctahedra; edges with eight Mg(2,2)Na2Mg8Si2 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four Mg(1,1,1)Na2Mg8Si2 cuboctahedra; faces with four equivalent Mg(2)Na2Mg8Si2 cuboctahedra; and faces with six equivalent Mg(4)Na2Mg10 cuboctahedra.
NaMg6Si crystallizes in the orthorhombic Amm2 space group. Na(1) is bonded to two equivalent Mg(4); four Mg(1,1,1); four equivalent Mg(2); and two equivalent Si(1) atoms to form NaMg10Si2 cuboctahedra that share corners with four equivalent Si(1)Na2Mg10 cuboctahedra; corners with six equivalent Na(1)Mg10Si2 cuboctahedra; corners with eight Mg(1,1,1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Si(1)Na2Mg10 cuboctahedra; edges with four equivalent Mg(4)Na2Mg10 cuboctahedra; edges with four Mg(1,1,1)Na2Mg8Si2 cuboctahedra; edges with eight Mg(2,2)Na2Mg8Si2 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four Mg(1,1,1)Na2Mg8Si2 cuboctahedra; faces with four equivalent Mg(2)Na2Mg8Si2 cuboctahedra; and faces with six equivalent Mg(3)Mg10Si2 cuboctahedra. Both Na(1)-Mg(4) bond lengths are 3.13 Å. There are two shorter (3.19 Å) and two longer (3.21 Å) Na(1)-Mg(1,1,1) bond lengths. All Na(1)-Mg(2) bond lengths are 3.12 Å. Both Na(1)-Si(1) bond lengths are 3.17 Å. There are seven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Si(1) atoms to form distorted MgNa2Mg8Si2 cuboctahedra that share corners with four equivalent Na(1)Mg10Si2 cuboctahedra; corners with four equivalent Si(1)Na2Mg10 cuboctahedra; corners with ten Mg(1,1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Na(1)Mg10Si2 cuboctahedra; edges with two equivalent Mg(1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Si(1)Na2Mg10 cuboctahedra; edges with four equivalent Mg(3)Mg10Si2 cuboctahedra; edges with four equivalent Mg(4)Na2Mg10 cuboctahedra; edges with four equivalent Mg(2)Na2Mg8Si2 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four Mg(1,1)Na2Mg8Si2 cuboctahedra; and faces with eight Mg(2,2)Na2Mg8Si2 cuboctahedra. There is one shorter (3.15 Å) and one longer (3.19 Å) Mg(1)-Mg(1) bond length. Both Mg(1)-Mg(2) bond lengths are 3.13 Å. Both Mg(1)-Mg(3) bond lengths are 3.12 Å. Both Mg(1)-Mg(4) bond lengths are 3.10 Å. There is one shorter (3.18 Å) and one longer (3.22 Å) Mg(1)-Si(1) bond length. In the second Mg site, Mg(1) is bonded to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Si(1) atoms to form distorted MgNa2Mg8Si2 cuboctahedra that share corners with four equivalent Na(1)Mg10Si2 cuboctahedra; corners with four equivalent Si(1)Na2Mg10 cuboctahedra; corners with ten Mg(1,1,1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Na(1)Mg10Si2 cuboctahedra; edges with two equivalent Mg(1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Si(1)Na2Mg10 cuboctahedra; edges with four equivalent Mg(3)Mg10Si2 cuboctahedra; edges with four equivalent Mg(4)Na2Mg10 cuboctahedra; edges with four equivalent Mg(2)Na2Mg8Si2 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four Mg(1,1)Na2Mg8Si2 cuboctahedra; and faces with eight Mg(2,2)Na2Mg8Si2 cuboctahedra. Both Mg(1)-Mg(2) bond lengths are 3.13 Å. Both Mg(1)-Mg(3) bond lengths are 3.12 Å. Both Mg(1)-Mg(4) bond lengths are 3.10 Å. There is one shorter (3.18 Å) and one longer (3.22 Å) Mg(1)-Si(1) bond length. In the third Mg site, Mg(2) is bonded to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Si(1) atoms to form distorted MgNa2Mg8Si2 cuboctahedra that share corners with four equivalent Mg(3)Mg10Si2 cuboctahedra; corners with four equivalent Mg(4)Na2Mg10 cuboctahedra; corners with ten Mg(2,2)Na2Mg8Si2 cuboctahedra; edges with two equivalent Mg(3)Mg10Si2 cuboctahedra; edges with two equivalent Mg(4)Na2Mg10 cuboctahedra; edges with two equivalent Mg(2)Na2Mg8Si2 cuboctahedra; edges with four equivalent Na(1)Mg10Si2 cuboctahedra; edges with four equivalent Mg(1)Na2Mg8Si2 cuboctahedra; edges with four equivalent Si(1)Na2Mg10 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four equivalent Mg(2)Na2Mg8Si2 cuboctahedra; and faces with eight Mg(1,1)Na2Mg8Si2 cuboctahedra. There is one shorter (3.10 Å) and one longer (3.24 Å) Mg(2)-Mg(2) bond length. There is one shorter (3.15 Å) and one longer (3.24 Å) Mg(2)-Mg(3) bond length. There is one shorter (3.18 Å) and one longer (3.22 Å) Mg(2)-Mg(4) bond length. Both Mg(2)-Si(1) bond lengths are 3.08 Å. In the fourth Mg site, Mg(3) is bonded to two equivalent Mg(4); four Mg(1,1); four Mg(2,2); and two equivalent Si(1) atoms to form distorted MgMg10Si2 cuboctahedra that share corners with four equivalent Mg(4)Na2Mg10 cuboctahedra; corners with six equivalent Mg(3)Mg10Si2 cuboctahedra; corners with eight Mg(2,2)Na2Mg8Si2 cuboctahedra; edges with two equivalent Mg(4)Na2Mg10 cuboctahedra; edges with four Mg(2,2)Na2Mg8Si2 cuboctahedra; edges with four equivalent Si(1)Na2Mg10 cuboctahedra; edges with eight Mg(1,1,1)Na2Mg8Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four Mg(1,1)Na2Mg8Si2 cuboctahedra; faces with four Mg(2,2)Na2Mg8Si2 cuboctahedra; and faces with six equivalent Na(1)Mg10Si2 cuboctahedra. Both Mg(3)-Mg(4) bond lengths are 3.17 Å. The Mg(3)-Mg(2) bond length is 3.24 Å. Both Mg(3)-Si(1) bond lengths are 3.12 Å. In the fifth Mg site, Mg(4) 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 Mg(3)Mg10Si2 cuboctahedra; corners with six equivalent Mg(4)Na2Mg10 cuboctahedra; corners with eight Mg(2,2)Na2Mg8Si2 cuboctahedra; edges with two equivalent Mg(3)Mg10Si2 cuboctahedra; edges with four equivalent Na(1)Mg10Si2 cuboctahedra; edges with four Mg(2,2)Na2Mg8Si2 cuboctahedra; edges with eight Mg(1,1,1)Na2Mg8Si2 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with four Mg(1,1)Na2Mg8Si2 cuboctahedra; faces with four Mg(2,2)Na2Mg8Si2 cuboctahedra; and faces with six equivalent Si(1)Na2Mg10 cuboctahedra. The Mg(4)-Mg(2) bond length is 3.18 Å. In the sixth Mg site, Mg(1) is bonded to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Si(1) atoms to form distorted MgNa2Mg8Si2 cuboctahedra that share corners with four equivalent Na(1)Mg10Si2 cuboctahedra; corners with four equivalent Si(1)Na2Mg10 cuboctahedra; corners with ten Mg(1,1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Na(1)Mg10Si2 cuboctahedra; edges with two equivalent Mg(1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Si(1)Na2Mg10 cuboctahedra; edges with four equivalent Mg(3)Mg10Si2 cuboctahedra; edges with four equivalent Mg(4)Na2Mg10 cuboctahedra; edges with four equivalent Mg(2)Na2Mg8Si2 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four Mg(1,1)Na2Mg8Si2 cuboctahedra; and faces with eight Mg(2,2)Na2Mg8Si2 cuboctahedra. There is one shorter (3.15 Å) and one longer (3.19 Å) Mg(1)-Mg(1) bond length. Both Mg(1)-Mg(2) bond lengths are 3.13 Å. Both Mg(1)-Mg(3) bond lengths are 3.12 Å. Both Mg(1)-Mg(4) bond lengths are 3.10 Å. There is one shorter (3.18 Å) and one longer (3.22 Å) Mg(1)-Si(1) bond length. In the seventh Mg site, Mg(2) is bonded to two equivalent Na(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Si(1) atoms to form distorted MgNa2Mg8Si2 cuboctahedra that share corners with four equivalent Mg(3)Mg10Si2 cuboctahedra; corners with four equivalent Mg(4)Na2Mg10 cuboctahedra; corners with ten Mg(2,2)Na2Mg8Si2 cuboctahedra; edges with two equivalent Mg(3)Mg10Si2 cuboctahedra; edges with two equivalent Mg(4)Na2Mg10 cuboctahedra; edges with two equivalent Mg(2)Na2Mg8Si2 cuboctahedra; edges with four equivalent Na(1)Mg10Si2 cuboctahedra; edges with four equivalent Mg(1)Na2Mg8Si2 cuboctahedra; edges with four equivalent Si(1)Na2Mg10 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Mg(4)Na2Mg10 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four Mg(2,2)Na2Mg8Si2 cuboctahedra; and faces with eight Mg(1,1,1)Na2Mg8Si2 cuboctahedra. Both Mg(2)-Na(1) bond lengths are 3.12 Å. There is one shorter (3.10 Å) and one longer (3.24 Å) Mg(2)-Mg(2) bond length. Both Mg(2)-Si(1) bond lengths are 3.08 Å. Si(1) is bonded to two equivalent Na(1); two equivalent Mg(3); four Mg(1,1,1); and four equivalent Mg(2) atoms to form SiNa2Mg10 cuboctahedra that share corners with four equivalent Na(1)Mg10Si2 cuboctahedra; corners with six equivalent Si(1)Na2Mg10 cuboctahedra; corners with eight Mg(1,1,1)Na2Mg8Si2 cuboctahedra; edges with two equivalent Na(1)Mg10Si2 cuboctahedra; edges with four equivalent Mg(3)Mg10Si2 cuboctahedra; edges with four Mg(1,1,1)Na2Mg8Si2 cuboctahedra; edges with eight Mg(2,2)Na2Mg8Si2 cuboctahedra; faces with two equivalent Na(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Mg10Si2 cuboctahedra; faces with two equivalent Si(1)Na2Mg10 cuboctahedra; faces with four Mg(1,1,1)Na2Mg8Si2 cuboctahedra; faces with four equivalent Mg(2)Na2Mg8Si2 cuboctahedra; and faces with six equivalent Mg(4)Na2Mg10 cuboctahedra.