Mg14CBi crystallizes in the hexagonal P-6m2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 10-coordinate geometry to 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 distorted linear geometry to two equivalent Mg(4) and two equivalent Bi(1) atoms. In the third Mg site, Mg(3) is bonded in a 12-coordinate geometry to two equivalent Mg(1), two equivalent Mg(4), one C(1), and one Bi(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 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 Bi(1)Mg12 cuboctahedra. C(1) is bonded in a 6-coordinate geometry to six equivalent Mg(3) atoms. Bi(1) is bonded to six equivalent Mg(2) and six equivalent Mg(3) atoms to form BiMg12 cuboctahedra that share corners with six equivalent Bi(1)Mg12 cuboctahedra and faces with six equivalent Mg(4)Mg12 cuboctahedra.
Mg14CBi crystallizes in the hexagonal P-6m2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 10-coordinate geometry to two equivalent Mg(4), four equivalent Mg(1), and four equivalent Mg(3) atoms. Both Mg(1)-Mg(4) bond lengths are 3.08 Å. There are two shorter (3.05 Å) and two longer (3.27 Å) Mg(1)-Mg(1) bond lengths. All Mg(1)-Mg(3) bond lengths are 2.95 Å. In the second Mg site, Mg(2) is bonded in a distorted linear geometry to two equivalent Mg(4) and two equivalent Bi(1) atoms. Both Mg(2)-Mg(4) bond lengths are 3.12 Å. Both Mg(2)-Bi(1) bond lengths are 3.16 Å. In the third Mg site, Mg(3) is bonded in a 12-coordinate geometry to two equivalent Mg(1), two equivalent Mg(4), one C(1), and one Bi(1) atom. Both Mg(3)-Mg(4) bond lengths are 3.17 Å. The Mg(3)-C(1) bond length is 2.88 Å. The Mg(3)-Bi(1) bond length is 3.29 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 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 Bi(1)Mg12 cuboctahedra. C(1) is bonded in a 6-coordinate geometry to six equivalent Mg(3) atoms. Bi(1) is bonded to six equivalent Mg(2) and six equivalent Mg(3) atoms to form BiMg12 cuboctahedra that share corners with six equivalent Bi(1)Mg12 cuboctahedra and faces with six equivalent Mg(4)Mg12 cuboctahedra.