KNaMg6 crystallizes in the orthorhombic Amm2 space group. K(1) is bonded to two equivalent Na(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form KNa2Mg10 cuboctahedra that share corners with six equivalent K(1)Na2Mg10 cuboctahedra, edges with four equivalent Na(1)K2Mg10 cuboctahedra, faces with two equivalent K(1)Na2Mg10 cuboctahedra, faces with two equivalent Na(1)K2Mg10 cuboctahedra, and faces with six equivalent Mg(4)Na2Mg10 cuboctahedra. Na(1) is bonded to two equivalent K(1), two equivalent Mg(4), four equivalent Mg(1), and four equivalent Mg(3) atoms to form NaK2Mg10 cuboctahedra that share corners with four equivalent Mg(4)Na2Mg10 cuboctahedra, corners with six equivalent Na(1)K2Mg10 cuboctahedra, edges with two equivalent Mg(4)Na2Mg10 cuboctahedra, edges with four equivalent K(1)Na2Mg10 cuboctahedra, faces with two equivalent K(1)Na2Mg10 cuboctahedra, faces with two equivalent Na(1)K2Mg10 cuboctahedra, and faces with two equivalent Mg(4)Na2Mg10 cuboctahedra. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to two equivalent K(1), two equivalent Na(1), two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms. In the second Mg site, Mg(2) is bonded in a 12-coordinate geometry to two equivalent K(1), two equivalent Mg(4), four equivalent Mg(1), and four equivalent Mg(3) atoms. In the third Mg site, Mg(3) is bonded in a 11-coordinate geometry to two equivalent K(1), two equivalent Na(1), one Mg(3), two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(4) 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)K2Mg10 cuboctahedra, corners with six equivalent Mg(4)Na2Mg10 cuboctahedra, edges with two equivalent Na(1)K2Mg10 cuboctahedra, faces with two equivalent Na(1)K2Mg10 cuboctahedra, faces with two equivalent Mg(4)Na2Mg10 cuboctahedra, and faces with six equivalent K(1)Na2Mg10 cuboctahedra.
KNaMg6 crystallizes in the orthorhombic Amm2 space group. K(1) is bonded to two equivalent Na(1), two equivalent Mg(2), four equivalent Mg(1), and four equivalent Mg(3) atoms to form KNa2Mg10 cuboctahedra that share corners with six equivalent K(1)Na2Mg10 cuboctahedra, edges with four equivalent Na(1)K2Mg10 cuboctahedra, faces with two equivalent K(1)Na2Mg10 cuboctahedra, faces with two equivalent Na(1)K2Mg10 cuboctahedra, and faces with six equivalent Mg(4)Na2Mg10 cuboctahedra. Both K(1)-Na(1) bond lengths are 3.34 Å. Both K(1)-Mg(2) bond lengths are 3.46 Å. There are two shorter (3.41 Å) and two longer (3.47 Å) K(1)-Mg(1) bond lengths. All K(1)-Mg(3) bond lengths are 3.47 Å. Na(1) is bonded to two equivalent K(1), two equivalent Mg(4), four equivalent Mg(1), and four equivalent Mg(3) atoms to form NaK2Mg10 cuboctahedra that share corners with four equivalent Mg(4)Na2Mg10 cuboctahedra, corners with six equivalent Na(1)K2Mg10 cuboctahedra, edges with two equivalent Mg(4)Na2Mg10 cuboctahedra, edges with four equivalent K(1)Na2Mg10 cuboctahedra, faces with two equivalent K(1)Na2Mg10 cuboctahedra, faces with two equivalent Na(1)K2Mg10 cuboctahedra, and faces with two equivalent Mg(4)Na2Mg10 cuboctahedra. Both Na(1)-Mg(4) bond lengths are 3.46 Å. All Na(1)-Mg(1) bond lengths are 3.38 Å. There are two shorter (3.25 Å) and two longer (3.63 Å) Na(1)-Mg(3) bond lengths. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to two equivalent K(1), two equivalent Na(1), two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms. There is one shorter (3.40 Å) and one longer (3.48 Å) Mg(1)-Mg(2) bond length. Both Mg(1)-Mg(3) bond lengths are 3.26 Å. Both Mg(1)-Mg(4) bond lengths are 3.34 Å. In the second Mg site, Mg(2) is bonded in a 12-coordinate geometry to two equivalent K(1), two equivalent Mg(4), four equivalent Mg(1), and four equivalent Mg(3) atoms. Both Mg(2)-Mg(4) bond lengths are 3.35 Å. All Mg(2)-Mg(3) bond lengths are 3.30 Å. In the third Mg site, Mg(3) is bonded in a 11-coordinate geometry to two equivalent K(1), two equivalent Na(1), one Mg(3), two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(4) atoms. The Mg(3)-Mg(3) bond length is 3.19 Å. There is one shorter (3.43 Å) and one longer (3.45 Å) Mg(3)-Mg(4) bond length. 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)K2Mg10 cuboctahedra, corners with six equivalent Mg(4)Na2Mg10 cuboctahedra, edges with two equivalent Na(1)K2Mg10 cuboctahedra, faces with two equivalent Na(1)K2Mg10 cuboctahedra, faces with two equivalent Mg(4)Na2Mg10 cuboctahedra, and faces with six equivalent K(1)Na2Mg10 cuboctahedra.