KMg14Ni crystallizes in the hexagonal P-6m2 space group. K(1) is bonded to six equivalent Mg(2) and six equivalent Mg(3) atoms to form KMg12 cuboctahedra that share corners with six equivalent K(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(1)Mg10Ni2 cuboctahedra, faces with two equivalent Ni(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 to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Ni(1) atoms to form distorted MgMg10Ni2 cuboctahedra that share corners with four equivalent K(1)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg10Ni2 cuboctahedra, edges with two equivalent Ni(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Ni2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Ni(1)Mg12 cuboctahedra, and faces with four equivalent Mg(1)Mg10Ni2 cuboctahedra. In the second Mg site, Mg(2) is bonded in a 2-coordinate geometry to two equivalent K(1) and two equivalent Mg(4) atoms. In the third Mg site, Mg(3) is bonded in a 1-coordinate geometry to one K(1), two equivalent Mg(1), two equivalent Mg(4), and one Ni(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, edges with six equivalent Mg(1)Mg10Ni2 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with three equivalent K(1)Mg12 cuboctahedra, faces with three equivalent Mg(1)Mg10Ni2 cuboctahedra, and faces with three equivalent Ni(1)Mg12 cuboctahedra. Ni(1) is bonded to six equivalent Mg(1) and six equivalent Mg(3) atoms to form NiMg12 cuboctahedra that share corners with six equivalent Ni(1)Mg12 cuboctahedra, edges with six equivalent Mg(1)Mg10Ni2 cuboctahedra, faces with two equivalent K(1)Mg12 cuboctahedra, faces with six equivalent Mg(1)Mg10Ni2 cuboctahedra, and faces with six equivalent Mg(4)Mg12 cuboctahedra.
KMg14Ni crystallizes in the hexagonal P-6m2 space group. K(1) is bonded to six equivalent Mg(2) and six equivalent Mg(3) atoms to form KMg12 cuboctahedra that share corners with six equivalent K(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(1)Mg10Ni2 cuboctahedra, faces with two equivalent Ni(1)Mg12 cuboctahedra, and faces with six equivalent Mg(4)Mg12 cuboctahedra. All K(1)-Mg(2) bond lengths are 3.19 Å. All K(1)-Mg(3) bond lengths are 3.45 Å. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Ni(1) atoms to form distorted MgMg10Ni2 cuboctahedra that share corners with four equivalent K(1)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg10Ni2 cuboctahedra, edges with two equivalent Ni(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Ni2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Ni(1)Mg12 cuboctahedra, and faces with four equivalent Mg(1)Mg10Ni2 cuboctahedra. Both Mg(1)-Mg(4) bond lengths are 3.26 Å. There are two shorter (3.08 Å) and two longer (3.29 Å) Mg(1)-Mg(1) bond lengths. All Mg(1)-Mg(3) bond lengths are 3.00 Å. Both Mg(1)-Ni(1) bond lengths are 3.19 Å. In the second Mg site, Mg(2) is bonded in a 2-coordinate geometry to two equivalent K(1) and two equivalent Mg(4) atoms. Both Mg(2)-Mg(4) bond lengths are 3.15 Å. In the third Mg site, Mg(3) is bonded in a 1-coordinate geometry to one K(1), two equivalent Mg(1), two equivalent Mg(4), and one Ni(1) atom. Both Mg(3)-Mg(4) bond lengths are 3.22 Å. The Mg(3)-Ni(1) bond length is 2.94 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, edges with six equivalent Mg(1)Mg10Ni2 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with three equivalent K(1)Mg12 cuboctahedra, faces with three equivalent Mg(1)Mg10Ni2 cuboctahedra, and faces with three equivalent Ni(1)Mg12 cuboctahedra. Ni(1) is bonded to six equivalent Mg(1) and six equivalent Mg(3) atoms to form NiMg12 cuboctahedra that share corners with six equivalent Ni(1)Mg12 cuboctahedra, edges with six equivalent Mg(1)Mg10Ni2 cuboctahedra, faces with two equivalent K(1)Mg12 cuboctahedra, faces with six equivalent Mg(1)Mg10Ni2 cuboctahedra, and faces with six equivalent Mg(4)Mg12 cuboctahedra.