MgPm5 crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded in a 10-coordinate geometry to two equivalent Pm(3), two equivalent Pm(4), two equivalent Pm(5), and four equivalent Pm(2) atoms. There are five inequivalent Pm sites. In the first Pm site, Pm(1) is bonded to two equivalent Pm(1), two equivalent Pm(2), two equivalent Pm(3), two equivalent Pm(5), and four equivalent Pm(4) atoms to form PmPm12 cuboctahedra that share corners with six equivalent Pm(3)Pm10Mg2 cuboctahedra, corners with six equivalent Pm(1)Pm12 cuboctahedra, corners with six equivalent Pm(2)Pm8Mg4 cuboctahedra, edges with three equivalent Pm(3)Pm10Mg2 cuboctahedra, edges with three equivalent Pm(2)Pm8Mg4 cuboctahedra, edges with four equivalent Pm(4)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(3)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(2)Pm8Mg4 cuboctahedra, faces with four equivalent Pm(4)Pm10Mg2 cuboctahedra, faces with four equivalent Pm(1)Pm12 cuboctahedra, and faces with six equivalent Pm(5)Pm10Mg2 cuboctahedra. In the second Pm site, Pm(2) is bonded to four equivalent Mg(1), two equivalent Pm(1), two equivalent Pm(2), two equivalent Pm(3), and two equivalent Pm(4) atoms to form distorted PmPm8Mg4 cuboctahedra that share corners with six equivalent Pm(3)Pm10Mg2 cuboctahedra, corners with six equivalent Pm(1)Pm12 cuboctahedra, corners with six equivalent Pm(2)Pm8Mg4 cuboctahedra, edges with three equivalent Pm(3)Pm10Mg2 cuboctahedra, edges with three equivalent Pm(1)Pm12 cuboctahedra, edges with eight equivalent Pm(5)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(3)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(5)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(1)Pm12 cuboctahedra, faces with four equivalent Pm(2)Pm8Mg4 cuboctahedra, and faces with six equivalent Pm(4)Pm10Mg2 cuboctahedra. In the third Pm site, Pm(3) is bonded to two equivalent Mg(1), two equivalent Pm(1), two equivalent Pm(2), two equivalent Pm(3), and four equivalent Pm(5) atoms to form PmPm10Mg2 cuboctahedra that share corners with six equivalent Pm(3)Pm10Mg2 cuboctahedra, corners with six equivalent Pm(1)Pm12 cuboctahedra, corners with six equivalent Pm(2)Pm8Mg4 cuboctahedra, edges with three equivalent Pm(1)Pm12 cuboctahedra, edges with three equivalent Pm(2)Pm8Mg4 cuboctahedra, edges with four equivalent Pm(5)Pm10Mg2 cuboctahedra, edges with eight equivalent Pm(4)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(4)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(1)Pm12 cuboctahedra, faces with two equivalent Pm(2)Pm8Mg4 cuboctahedra, faces with four equivalent Pm(3)Pm10Mg2 cuboctahedra, and faces with four equivalent Pm(5)Pm10Mg2 cuboctahedra. In the fourth Pm site, Pm(4) is bonded to two equivalent Mg(1), two equivalent Pm(2), two equivalent Pm(4), two equivalent Pm(5), and four equivalent Pm(1) atoms to form distorted PmPm10Mg2 cuboctahedra that share corners with six equivalent Pm(4)Pm10Mg2 cuboctahedra, corners with six equivalent Pm(5)Pm10Mg2 cuboctahedra, edges with three equivalent Pm(5)Pm10Mg2 cuboctahedra, edges with four equivalent Pm(1)Pm12 cuboctahedra, edges with eight equivalent Pm(3)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(3)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(5)Pm10Mg2 cuboctahedra, faces with four equivalent Pm(4)Pm10Mg2 cuboctahedra, faces with four equivalent Pm(1)Pm12 cuboctahedra, and faces with six equivalent Pm(2)Pm8Mg4 cuboctahedra. In the fifth Pm site, Pm(5) is bonded to two equivalent Mg(1), two equivalent Pm(1), two equivalent Pm(4), two equivalent Pm(5), and four equivalent Pm(3) atoms to form distorted PmPm10Mg2 cuboctahedra that share corners with six equivalent Pm(4)Pm10Mg2 cuboctahedra, corners with six equivalent Pm(5)Pm10Mg2 cuboctahedra, edges with three equivalent Pm(4)Pm10Mg2 cuboctahedra, edges with four equivalent Pm(3)Pm10Mg2 cuboctahedra, edges with eight equivalent Pm(2)Pm8Mg4 cuboctahedra, faces with two equivalent Pm(4)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(2)Pm8Mg4 cuboctahedra, faces with four equivalent Pm(3)Pm10Mg2 cuboctahedra, faces with four equivalent Pm(5)Pm10Mg2 cuboctahedra, and faces with six equivalent Pm(1)Pm12 cuboctahedra.
MgPm5 crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded in a 10-coordinate geometry to two equivalent Pm(3), two equivalent Pm(4), two equivalent Pm(5), and four equivalent Pm(2) atoms. Both Mg(1)-Pm(3) bond lengths are 3.61 Å. Both Mg(1)-Pm(4) bond lengths are 3.53 Å. Both Mg(1)-Pm(5) bond lengths are 3.47 Å. All Mg(1)-Pm(2) bond lengths are 3.54 Å. There are five inequivalent Pm sites. In the first Pm site, Pm(1) is bonded to two equivalent Pm(1), two equivalent Pm(2), two equivalent Pm(3), two equivalent Pm(5), and four equivalent Pm(4) atoms to form PmPm12 cuboctahedra that share corners with six equivalent Pm(3)Pm10Mg2 cuboctahedra, corners with six equivalent Pm(1)Pm12 cuboctahedra, corners with six equivalent Pm(2)Pm8Mg4 cuboctahedra, edges with three equivalent Pm(3)Pm10Mg2 cuboctahedra, edges with three equivalent Pm(2)Pm8Mg4 cuboctahedra, edges with four equivalent Pm(4)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(3)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(2)Pm8Mg4 cuboctahedra, faces with four equivalent Pm(4)Pm10Mg2 cuboctahedra, faces with four equivalent Pm(1)Pm12 cuboctahedra, and faces with six equivalent Pm(5)Pm10Mg2 cuboctahedra. Both Pm(1)-Pm(1) bond lengths are 3.71 Å. Both Pm(1)-Pm(2) bond lengths are 3.60 Å. Both Pm(1)-Pm(3) bond lengths are 3.64 Å. Both Pm(1)-Pm(5) bond lengths are 3.73 Å. All Pm(1)-Pm(4) bond lengths are 3.56 Å. In the second Pm site, Pm(2) is bonded to four equivalent Mg(1), two equivalent Pm(1), two equivalent Pm(2), two equivalent Pm(3), and two equivalent Pm(4) atoms to form distorted PmPm8Mg4 cuboctahedra that share corners with six equivalent Pm(3)Pm10Mg2 cuboctahedra, corners with six equivalent Pm(1)Pm12 cuboctahedra, corners with six equivalent Pm(2)Pm8Mg4 cuboctahedra, edges with three equivalent Pm(3)Pm10Mg2 cuboctahedra, edges with three equivalent Pm(1)Pm12 cuboctahedra, edges with eight equivalent Pm(5)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(3)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(5)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(1)Pm12 cuboctahedra, faces with four equivalent Pm(2)Pm8Mg4 cuboctahedra, and faces with six equivalent Pm(4)Pm10Mg2 cuboctahedra. Both Pm(2)-Pm(2) bond lengths are 3.71 Å. Both Pm(2)-Pm(3) bond lengths are 3.47 Å. Both Pm(2)-Pm(4) bond lengths are 3.65 Å. In the third Pm site, Pm(3) is bonded to two equivalent Mg(1), two equivalent Pm(1), two equivalent Pm(2), two equivalent Pm(3), and four equivalent Pm(5) atoms to form PmPm10Mg2 cuboctahedra that share corners with six equivalent Pm(3)Pm10Mg2 cuboctahedra, corners with six equivalent Pm(1)Pm12 cuboctahedra, corners with six equivalent Pm(2)Pm8Mg4 cuboctahedra, edges with three equivalent Pm(1)Pm12 cuboctahedra, edges with three equivalent Pm(2)Pm8Mg4 cuboctahedra, edges with four equivalent Pm(5)Pm10Mg2 cuboctahedra, edges with eight equivalent Pm(4)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(4)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(1)Pm12 cuboctahedra, faces with two equivalent Pm(2)Pm8Mg4 cuboctahedra, faces with four equivalent Pm(3)Pm10Mg2 cuboctahedra, and faces with four equivalent Pm(5)Pm10Mg2 cuboctahedra. Both Pm(3)-Pm(3) bond lengths are 3.71 Å. All Pm(3)-Pm(5) bond lengths are 3.54 Å. In the fourth Pm site, Pm(4) is bonded to two equivalent Mg(1), two equivalent Pm(2), two equivalent Pm(4), two equivalent Pm(5), and four equivalent Pm(1) atoms to form distorted PmPm10Mg2 cuboctahedra that share corners with six equivalent Pm(4)Pm10Mg2 cuboctahedra, corners with six equivalent Pm(5)Pm10Mg2 cuboctahedra, edges with three equivalent Pm(5)Pm10Mg2 cuboctahedra, edges with four equivalent Pm(1)Pm12 cuboctahedra, edges with eight equivalent Pm(3)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(3)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(5)Pm10Mg2 cuboctahedra, faces with four equivalent Pm(4)Pm10Mg2 cuboctahedra, faces with four equivalent Pm(1)Pm12 cuboctahedra, and faces with six equivalent Pm(2)Pm8Mg4 cuboctahedra. Both Pm(4)-Pm(4) bond lengths are 3.71 Å. Both Pm(4)-Pm(5) bond lengths are 3.71 Å. In the fifth Pm site, Pm(5) is bonded to two equivalent Mg(1), two equivalent Pm(1), two equivalent Pm(4), two equivalent Pm(5), and four equivalent Pm(3) atoms to form distorted PmPm10Mg2 cuboctahedra that share corners with six equivalent Pm(4)Pm10Mg2 cuboctahedra, corners with six equivalent Pm(5)Pm10Mg2 cuboctahedra, edges with three equivalent Pm(4)Pm10Mg2 cuboctahedra, edges with four equivalent Pm(3)Pm10Mg2 cuboctahedra, edges with eight equivalent Pm(2)Pm8Mg4 cuboctahedra, faces with two equivalent Pm(4)Pm10Mg2 cuboctahedra, faces with two equivalent Pm(2)Pm8Mg4 cuboctahedra, faces with four equivalent Pm(3)Pm10Mg2 cuboctahedra, faces with four equivalent Pm(5)Pm10Mg2 cuboctahedra, and faces with six equivalent Pm(1)Pm12 cuboctahedra. Both Pm(5)-Pm(5) bond lengths are 3.71 Å.