KMg14C crystallizes in the hexagonal P-6m2 space group. K(1) is bonded to six equivalent Mg(1) and six equivalent Mg(3) atoms to form KMg12 cuboctahedra that share corners with six equivalent K(1)Mg12 cuboctahedra and faces with six equivalent Mg(4)Mg12 cuboctahedra. There are four inequivalent Mg sites. In the first Mg site, Mg(1) 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 second Mg site, Mg(2) is bonded in a 10-coordinate geometry to two equivalent Mg(4), four equivalent Mg(2), and four equivalent Mg(3) atoms. In the third Mg site, Mg(3) is bonded in a 12-coordinate geometry to one K(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), and one C(1) atom. In the fourth Mg site, Mg(4) is bonded to three equivalent Mg(1), three equivalent Mg(2), and six equivalent Mg(3) atoms to form distorted MgMg12 cuboctahedra that share corners with six equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, and faces with three equivalent K(1)Mg12 cuboctahedra. C(1) is bonded in a 6-coordinate geometry to six equivalent Mg(3) atoms.
KMg14C crystallizes in the hexagonal P-6m2 space group. K(1) is bonded to six equivalent Mg(1) and six equivalent Mg(3) atoms to form KMg12 cuboctahedra that share corners with six equivalent K(1)Mg12 cuboctahedra and faces with six equivalent Mg(4)Mg12 cuboctahedra. All K(1)-Mg(1) bond lengths are 3.22 Å. All K(1)-Mg(3) bond lengths are 3.40 Å. There are four inequivalent Mg sites. In the first Mg site, Mg(1) 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(1)-Mg(4) bond lengths are 3.14 Å. There are two shorter (3.10 Å) and two longer (3.35 Å) Mg(1)-Mg(1) bond lengths. All Mg(1)-Mg(3) bond lengths are 3.43 Å. In the second Mg site, Mg(2) is bonded in a 10-coordinate geometry to two equivalent Mg(4), four equivalent Mg(2), and four equivalent Mg(3) atoms. Both Mg(2)-Mg(4) bond lengths are 3.19 Å. There are two shorter (3.07 Å) and two longer (3.38 Å) Mg(2)-Mg(2) bond lengths. All Mg(2)-Mg(3) bond lengths are 2.96 Å. In the third Mg site, Mg(3) is bonded in a 12-coordinate geometry to one K(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), and one C(1) atom. Both Mg(3)-Mg(4) bond lengths are 3.25 Å. The Mg(3)-C(1) bond length is 2.87 Å. In the fourth Mg site, Mg(4) is bonded to three equivalent Mg(1), three equivalent Mg(2), and six equivalent Mg(3) atoms to form distorted MgMg12 cuboctahedra that share corners with six equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, and faces with three equivalent K(1)Mg12 cuboctahedra. C(1) is bonded in a 6-coordinate geometry to six equivalent Mg(3) atoms.