SrMg14Mn crystallizes in the hexagonal P-6m2 space group. Sr(1) is bonded to six equivalent Mg(2) and six equivalent Mg(3) atoms to form SrMg12 cuboctahedra that share corners with six equivalent Sr(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with six equivalent Mg(2)Sr2Mg10 cuboctahedra, edges with twelve equivalent Mg(3)SrMg10Mn cuboctahedra, faces with two equivalent Mn(1)Mg12 cuboctahedra, faces with six equivalent Mg(4)Mg12 cuboctahedra, faces with six equivalent Mg(2)Sr2Mg10 cuboctahedra, and faces with six equivalent Mg(3)SrMg10Mn 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 Mn(1) atoms to form MgMg10Mn2 cuboctahedra that share corners with four equivalent Sr(1)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg10Mn2 cuboctahedra, corners with eight equivalent Mg(2)Sr2Mg10 cuboctahedra, edges with two equivalent Mn(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(3)SrMg10Mn cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(2)Sr2Mg10 cuboctahedra, faces with two equivalent Mn(1)Mg12 cuboctahedra, faces with four equivalent Mg(1)Mg10Mn2 cuboctahedra, and faces with ten equivalent Mg(3)SrMg10Mn cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Sr(1), two equivalent Mg(4), four equivalent Mg(2), and four equivalent Mg(3) atoms to form distorted MgSr2Mg10 cuboctahedra that share corners with four equivalent Mn(1)Mg12 cuboctahedra, corners with six equivalent Mg(2)Sr2Mg10 cuboctahedra, corners with eight equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with two equivalent Sr(1)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(2)Sr2Mg10 cuboctahedra, edges with eight equivalent Mg(3)SrMg10Mn cuboctahedra, faces with two equivalent Sr(1)Mg12 cuboctahedra, faces with two equivalent Mg(1)Mg10Mn2 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with four equivalent Mg(2)Sr2Mg10 cuboctahedra, and faces with ten equivalent Mg(3)SrMg10Mn cuboctahedra. In the third Mg site, Mg(3) is bonded to one Sr(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), four equivalent Mg(3), and one Mn(1) atom to form distorted MgSrMg10Mn cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra, corners with fourteen equivalent Mg(3)SrMg10Mn cuboctahedra, edges with two equivalent Sr(1)Mg12 cuboctahedra, edges with two equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Mn(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with four equivalent Mg(2)Sr2Mg10 cuboctahedra, edges with four equivalent Mg(3)SrMg10Mn cuboctahedra,  a faceface with one Sr(1)Mg12 cuboctahedra,  a faceface with one Mn(1)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with five equivalent Mg(1)Mg10Mn2 cuboctahedra, faces with five equivalent Mg(2)Sr2Mg10 cuboctahedra, and faces with six equivalent Mg(3)SrMg10Mn cuboctahedra. 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, corners with twelve equivalent Mg(3)SrMg10Mn cuboctahedra, edges with six equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with six equivalent Mg(2)Sr2Mg10 cuboctahedra, edges with six equivalent Mg(3)SrMg10Mn cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with three equivalent Sr(1)Mg12 cuboctahedra, faces with three equivalent Mg(1)Mg10Mn2 cuboctahedra, faces with three equivalent Mg(2)Sr2Mg10 cuboctahedra, faces with three equivalent Mn(1)Mg12 cuboctahedra, and faces with six equivalent Mg(3)SrMg10Mn cuboctahedra. Mn(1) is bonded to six equivalent Mg(1) and six equivalent Mg(3) atoms to form MnMg12 cuboctahedra that share corners with six equivalent Mn(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(2)Sr2Mg10 cuboctahedra, edges with six equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with twelve equivalent Mg(3)SrMg10Mn cuboctahedra, faces with two equivalent Sr(1)Mg12 cuboctahedra, faces with six equivalent Mg(1)Mg10Mn2 cuboctahedra, faces with six equivalent Mg(4)Mg12 cuboctahedra, and faces with six equivalent Mg(3)SrMg10Mn cuboctahedra.
SrMg14Mn crystallizes in the hexagonal P-6m2 space group. Sr(1) is bonded to six equivalent Mg(2) and six equivalent Mg(3) atoms to form SrMg12 cuboctahedra that share corners with six equivalent Sr(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with six equivalent Mg(2)Sr2Mg10 cuboctahedra, edges with twelve equivalent Mg(3)SrMg10Mn cuboctahedra, faces with two equivalent Mn(1)Mg12 cuboctahedra, faces with six equivalent Mg(4)Mg12 cuboctahedra, faces with six equivalent Mg(2)Sr2Mg10 cuboctahedra, and faces with six equivalent Mg(3)SrMg10Mn cuboctahedra. All Sr(1)-Mg(2) bond lengths are 3.26 Å. All Sr(1)-Mg(3) bond lengths are 3.38 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 Mn(1) atoms to form MgMg10Mn2 cuboctahedra that share corners with four equivalent Sr(1)Mg12 cuboctahedra, corners with six equivalent Mg(1)Mg10Mn2 cuboctahedra, corners with eight equivalent Mg(2)Sr2Mg10 cuboctahedra, edges with two equivalent Mn(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(3)SrMg10Mn cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(2)Sr2Mg10 cuboctahedra, faces with two equivalent Mn(1)Mg12 cuboctahedra, faces with four equivalent Mg(1)Mg10Mn2 cuboctahedra, and faces with ten equivalent Mg(3)SrMg10Mn cuboctahedra. Both Mg(1)-Mg(4) bond lengths are 3.27 Å. There are two shorter (3.24 Å) and two longer (3.28 Å) Mg(1)-Mg(1) bond lengths. All Mg(1)-Mg(3) bond lengths are 3.07 Å. Both Mg(1)-Mn(1) bond lengths are 3.26 Å. In the second Mg site, Mg(2) is bonded to two equivalent Sr(1), two equivalent Mg(4), four equivalent Mg(2), and four equivalent Mg(3) atoms to form distorted MgSr2Mg10 cuboctahedra that share corners with four equivalent Mn(1)Mg12 cuboctahedra, corners with six equivalent Mg(2)Sr2Mg10 cuboctahedra, corners with eight equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with two equivalent Sr(1)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(2)Sr2Mg10 cuboctahedra, edges with eight equivalent Mg(3)SrMg10Mn cuboctahedra, faces with two equivalent Sr(1)Mg12 cuboctahedra, faces with two equivalent Mg(1)Mg10Mn2 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with four equivalent Mg(2)Sr2Mg10 cuboctahedra, and faces with ten equivalent Mg(3)SrMg10Mn cuboctahedra. Both Mg(2)-Mg(4) bond lengths are 3.21 Å. There are two shorter (3.14 Å) and two longer (3.38 Å) Mg(2)-Mg(2) bond lengths. All Mg(2)-Mg(3) bond lengths are 3.35 Å. In the third Mg site, Mg(3) is bonded to one Sr(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), four equivalent Mg(3), and one Mn(1) atom to form distorted MgSrMg10Mn cuboctahedra that share corners with four equivalent Mg(4)Mg12 cuboctahedra, corners with fourteen equivalent Mg(3)SrMg10Mn cuboctahedra, edges with two equivalent Sr(1)Mg12 cuboctahedra, edges with two equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Mn(1)Mg12 cuboctahedra, edges with four equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with four equivalent Mg(2)Sr2Mg10 cuboctahedra, edges with four equivalent Mg(3)SrMg10Mn cuboctahedra,  a faceface with one Sr(1)Mg12 cuboctahedra,  a faceface with one Mn(1)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with five equivalent Mg(1)Mg10Mn2 cuboctahedra, faces with five equivalent Mg(2)Sr2Mg10 cuboctahedra, and faces with six equivalent Mg(3)SrMg10Mn cuboctahedra. Both Mg(3)-Mg(4) bond lengths are 3.27 Å. There are two shorter (3.24 Å) and two longer (3.28 Å) Mg(3)-Mg(3) bond lengths. The Mg(3)-Mn(1) bond length is 3.08 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, corners with twelve equivalent Mg(3)SrMg10Mn cuboctahedra, edges with six equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with six equivalent Mg(2)Sr2Mg10 cuboctahedra, edges with six equivalent Mg(3)SrMg10Mn cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with three equivalent Sr(1)Mg12 cuboctahedra, faces with three equivalent Mg(1)Mg10Mn2 cuboctahedra, faces with three equivalent Mg(2)Sr2Mg10 cuboctahedra, faces with three equivalent Mn(1)Mg12 cuboctahedra, and faces with six equivalent Mg(3)SrMg10Mn cuboctahedra. Mn(1) is bonded to six equivalent Mg(1) and six equivalent Mg(3) atoms to form MnMg12 cuboctahedra that share corners with six equivalent Mn(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(2)Sr2Mg10 cuboctahedra, edges with six equivalent Mg(1)Mg10Mn2 cuboctahedra, edges with twelve equivalent Mg(3)SrMg10Mn cuboctahedra, faces with two equivalent Sr(1)Mg12 cuboctahedra, faces with six equivalent Mg(1)Mg10Mn2 cuboctahedra, faces with six equivalent Mg(4)Mg12 cuboctahedra, and faces with six equivalent Mg(3)SrMg10Mn cuboctahedra.