MgTm5 crystallizes in the trigonal R32 space group. Mg(1) is bonded to six Tm(1,1,1) and six equivalent Tm(2) atoms to form MgTm12 cuboctahedra that share corners with six equivalent Mg(1)Tm12 cuboctahedra; corners with twelve equivalent Tm(2)Tm9Mg3 cuboctahedra; edges with six equivalent Mg(1)Tm12 cuboctahedra; edges with twelve Tm(1,1,1)Tm10Mg2 cuboctahedra; faces with eight equivalent Tm(2)Tm9Mg3 cuboctahedra; and faces with twelve Tm(1,1,1)Tm10Mg2 cuboctahedra. There are six inequivalent Tm sites. In the first Tm site, Tm(1) is bonded to two equivalent Mg(1), four equivalent Tm(2), and six equivalent Tm(1) atoms to form TmTm10Mg2 cuboctahedra that share corners with eighteen Tm(1,1,1)Tm10Mg2 cuboctahedra; edges with four equivalent Mg(1)Tm12 cuboctahedra; edges with six equivalent Tm(1)Tm10Mg2 cuboctahedra; edges with eight equivalent Tm(2)Tm9Mg3 cuboctahedra; faces with four equivalent Mg(1)Tm12 cuboctahedra; faces with eight Tm(1,1)Tm10Mg2 cuboctahedra; and faces with eight equivalent Tm(2)Tm9Mg3 cuboctahedra. In the second Tm site, Tm(1) is bonded to two equivalent Mg(1); four equivalent Tm(2); and six Tm(1,1) atoms to form TmTm10Mg2 cuboctahedra that share corners with eighteen Tm(1,1,1,1)Tm10Mg2 cuboctahedra; edges with four equivalent Mg(1)Tm12 cuboctahedra; edges with six equivalent Tm(1)Tm10Mg2 cuboctahedra; edges with eight equivalent Tm(2)Tm9Mg3 cuboctahedra; faces with four equivalent Mg(1)Tm12 cuboctahedra; faces with eight Tm(1,1,1)Tm10Mg2 cuboctahedra; and faces with eight equivalent Tm(2)Tm9Mg3 cuboctahedra. In the third Tm site, Tm(2) is bonded to three equivalent Mg(1); three equivalent Tm(2); and six Tm(1,1,1) atoms to form TmTm9Mg3 cuboctahedra that share corners with six equivalent Mg(1)Tm12 cuboctahedra; corners with twelve equivalent Tm(2)Tm9Mg3 cuboctahedra; edges with six equivalent Tm(2)Tm9Mg3 cuboctahedra; edges with twelve Tm(1,1,1)Tm10Mg2 cuboctahedra; faces with four equivalent Mg(1)Tm12 cuboctahedra; faces with four equivalent Tm(2)Tm9Mg3 cuboctahedra; and faces with twelve Tm(1,1,1)Tm10Mg2 cuboctahedra. In the fourth Tm site, Tm(1) is bonded to two equivalent Mg(1); four equivalent Tm(2); and six Tm(1,1) atoms to form TmTm10Mg2 cuboctahedra that share corners with eighteen Tm(1,1,1,1)Tm10Mg2 cuboctahedra; edges with four equivalent Mg(1)Tm12 cuboctahedra; edges with six equivalent Tm(1)Tm10Mg2 cuboctahedra; edges with eight equivalent Tm(2)Tm9Mg3 cuboctahedra; faces with four equivalent Mg(1)Tm12 cuboctahedra; faces with eight Tm(1,1)Tm10Mg2 cuboctahedra; and faces with eight equivalent Tm(2)Tm9Mg3 cuboctahedra. In the fifth Tm site, Tm(1) is bonded to two equivalent Mg(1); four equivalent Tm(2); and six Tm(1,1) atoms to form TmTm10Mg2 cuboctahedra that share corners with eighteen Tm(1,1,1,1)Tm10Mg2 cuboctahedra; edges with four equivalent Mg(1)Tm12 cuboctahedra; edges with six equivalent Tm(1)Tm10Mg2 cuboctahedra; edges with eight equivalent Tm(2)Tm9Mg3 cuboctahedra; faces with four equivalent Mg(1)Tm12 cuboctahedra; faces with eight Tm(1,1)Tm10Mg2 cuboctahedra; and faces with eight equivalent Tm(2)Tm9Mg3 cuboctahedra. In the sixth Tm site, Tm(1) is bonded to two equivalent Mg(1), four equivalent Tm(2), and six equivalent Tm(1) atoms to form TmTm10Mg2 cuboctahedra that share corners with eighteen Tm(1,1,1)Tm10Mg2 cuboctahedra; edges with four equivalent Mg(1)Tm12 cuboctahedra; edges with six equivalent Tm(1)Tm10Mg2 cuboctahedra; edges with eight equivalent Tm(2)Tm9Mg3 cuboctahedra; faces with four equivalent Mg(1)Tm12 cuboctahedra; faces with eight Tm(1,1)Tm10Mg2 cuboctahedra; and faces with eight equivalent Tm(2)Tm9Mg3 cuboctahedra.
MgTm5 crystallizes in the trigonal R32 space group. Mg(1) is bonded to six Tm(1,1,1) and six equivalent Tm(2) atoms to form MgTm12 cuboctahedra that share corners with six equivalent Mg(1)Tm12 cuboctahedra; corners with twelve equivalent Tm(2)Tm9Mg3 cuboctahedra; edges with six equivalent Mg(1)Tm12 cuboctahedra; edges with twelve Tm(1,1,1)Tm10Mg2 cuboctahedra; faces with eight equivalent Tm(2)Tm9Mg3 cuboctahedra; and faces with twelve Tm(1,1,1)Tm10Mg2 cuboctahedra. All Mg(1)-Tm(1,1,1) bond lengths are 3.39 Å. All Mg(1)-Tm(2) bond lengths are 3.48 Å. There are six inequivalent Tm sites. In the first Tm site, Tm(1) is bonded to two equivalent Mg(1), four equivalent Tm(2), and six equivalent Tm(1) atoms to form TmTm10Mg2 cuboctahedra that share corners with eighteen Tm(1,1,1)Tm10Mg2 cuboctahedra; edges with four equivalent Mg(1)Tm12 cuboctahedra; edges with six equivalent Tm(1)Tm10Mg2 cuboctahedra; edges with eight equivalent Tm(2)Tm9Mg3 cuboctahedra; faces with four equivalent Mg(1)Tm12 cuboctahedra; faces with eight Tm(1,1)Tm10Mg2 cuboctahedra; and faces with eight equivalent Tm(2)Tm9Mg3 cuboctahedra. There are two shorter (3.40 Å) and two longer (3.43 Å) Tm(1)-Tm(2) bond lengths. There are four shorter (3.43 Å) and two longer (3.58 Å) Tm(1)-Tm(1) bond lengths. In the second Tm site, Tm(1) is bonded to two equivalent Mg(1); four equivalent Tm(2); and six Tm(1,1) atoms to form TmTm10Mg2 cuboctahedra that share corners with eighteen Tm(1,1,1,1)Tm10Mg2 cuboctahedra; edges with four equivalent Mg(1)Tm12 cuboctahedra; edges with six equivalent Tm(1)Tm10Mg2 cuboctahedra; edges with eight equivalent Tm(2)Tm9Mg3 cuboctahedra; faces with four equivalent Mg(1)Tm12 cuboctahedra; faces with eight Tm(1,1,1)Tm10Mg2 cuboctahedra; and faces with eight equivalent Tm(2)Tm9Mg3 cuboctahedra. There are two shorter (3.40 Å) and two longer (3.43 Å) Tm(1)-Tm(2) bond lengths. There are two shorter (3.43 Å) and one longer (3.58 Å) Tm(1)-Tm(1) bond length. In the third Tm site, Tm(2) is bonded to three equivalent Mg(1); three equivalent Tm(2); and six Tm(1,1,1) atoms to form TmTm9Mg3 cuboctahedra that share corners with six equivalent Mg(1)Tm12 cuboctahedra; corners with twelve equivalent Tm(2)Tm9Mg3 cuboctahedra; edges with six equivalent Tm(2)Tm9Mg3 cuboctahedra; edges with twelve Tm(1,1,1)Tm10Mg2 cuboctahedra; faces with four equivalent Mg(1)Tm12 cuboctahedra; faces with four equivalent Tm(2)Tm9Mg3 cuboctahedra; and faces with twelve Tm(1,1,1)Tm10Mg2 cuboctahedra. All Tm(2)-Tm(2) bond lengths are 3.48 Å. The Tm(2)-Tm(1) bond length is 3.43 Å. In the fourth Tm site, Tm(1) is bonded to two equivalent Mg(1); four equivalent Tm(2); and six Tm(1,1) atoms to form TmTm10Mg2 cuboctahedra that share corners with eighteen Tm(1,1,1,1)Tm10Mg2 cuboctahedra; edges with four equivalent Mg(1)Tm12 cuboctahedra; edges with six equivalent Tm(1)Tm10Mg2 cuboctahedra; edges with eight equivalent Tm(2)Tm9Mg3 cuboctahedra; faces with four equivalent Mg(1)Tm12 cuboctahedra; faces with eight Tm(1,1)Tm10Mg2 cuboctahedra; and faces with eight equivalent Tm(2)Tm9Mg3 cuboctahedra. Both Tm(1)-Mg(1) bond lengths are 3.39 Å. There are two shorter (3.40 Å) and two longer (3.43 Å) Tm(1)-Tm(2) bond lengths. There are four shorter (3.43 Å) and two longer (3.58 Å) Tm(1)-Tm(1,1) bond lengths. In the fifth Tm site, Tm(1) is bonded to two equivalent Mg(1); four equivalent Tm(2); and six Tm(1,1) atoms to form TmTm10Mg2 cuboctahedra that share corners with eighteen Tm(1,1,1,1)Tm10Mg2 cuboctahedra; edges with four equivalent Mg(1)Tm12 cuboctahedra; edges with six equivalent Tm(1)Tm10Mg2 cuboctahedra; edges with eight equivalent Tm(2)Tm9Mg3 cuboctahedra; faces with four equivalent Mg(1)Tm12 cuboctahedra; faces with eight Tm(1,1)Tm10Mg2 cuboctahedra; and faces with eight equivalent Tm(2)Tm9Mg3 cuboctahedra. Both Tm(1)-Mg(1) bond lengths are 3.39 Å. There are two shorter (3.40 Å) and two longer (3.43 Å) Tm(1)-Tm(2) bond lengths. There are two shorter (3.43 Å) and one longer (3.58 Å) Tm(1)-Tm(1) bond length. In the sixth Tm site, Tm(1) is bonded to two equivalent Mg(1), four equivalent Tm(2), and six equivalent Tm(1) atoms to form TmTm10Mg2 cuboctahedra that share corners with eighteen Tm(1,1,1)Tm10Mg2 cuboctahedra; edges with four equivalent Mg(1)Tm12 cuboctahedra; edges with six equivalent Tm(1)Tm10Mg2 cuboctahedra; edges with eight equivalent Tm(2)Tm9Mg3 cuboctahedra; faces with four equivalent Mg(1)Tm12 cuboctahedra; faces with eight Tm(1,1)Tm10Mg2 cuboctahedra; and faces with eight equivalent Tm(2)Tm9Mg3 cuboctahedra. There are four shorter (3.43 Å) and two longer (3.58 Å) Tm(1)-Tm(1) bond lengths.