Sr2Mg1 crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to two equivalent Sr(1), two equivalent Sr(2), two equivalent Sr(3), four equivalent Sr(4), and two equivalent Mg(1) atoms to form distorted SrSr10Mg2 cuboctahedra that share corners with six equivalent Sr(1)Sr10Mg2 cuboctahedra, corners with six equivalent Sr(3)Sr6Mg6 cuboctahedra, corners with six equivalent Sr(2)Sr8Mg4 cuboctahedra, edges with three equivalent Sr(3)Sr6Mg6 cuboctahedra, edges with three equivalent Sr(2)Sr8Mg4 cuboctahedra, edges with four equivalent Sr(4)Sr8Mg4 cuboctahedra, faces with two equivalent Sr(3)Sr6Mg6 cuboctahedra, faces with two equivalent Sr(2)Sr8Mg4 cuboctahedra, faces with four equivalent Sr(1)Sr10Mg2 cuboctahedra, and faces with four equivalent Sr(4)Sr8Mg4 cuboctahedra. In the second Sr site, Sr(2) is bonded to two equivalent Sr(1), two equivalent Sr(2), two equivalent Sr(3), two equivalent Sr(4), and four equivalent Mg(2) atoms to form distorted SrSr8Mg4 cuboctahedra that share corners with six equivalent Sr(1)Sr10Mg2 cuboctahedra, corners with six equivalent Sr(3)Sr6Mg6 cuboctahedra, corners with six equivalent Sr(2)Sr8Mg4 cuboctahedra, edges with three equivalent Sr(1)Sr10Mg2 cuboctahedra, edges with three equivalent Sr(3)Sr6Mg6 cuboctahedra, faces with two equivalent Sr(1)Sr10Mg2 cuboctahedra, faces with two equivalent Sr(3)Sr6Mg6 cuboctahedra, faces with four equivalent Sr(2)Sr8Mg4 cuboctahedra, and faces with six equivalent Sr(4)Sr8Mg4 cuboctahedra. In the third Sr site, Sr(3) is bonded to two equivalent Sr(1), two equivalent Sr(2), two equivalent Sr(3), two equivalent Mg(2), and four equivalent Mg(1) atoms to form distorted SrSr6Mg6 cuboctahedra that share corners with six equivalent Sr(1)Sr10Mg2 cuboctahedra, corners with six equivalent Sr(3)Sr6Mg6 cuboctahedra, corners with six equivalent Sr(2)Sr8Mg4 cuboctahedra, edges with three equivalent Sr(1)Sr10Mg2 cuboctahedra, edges with three equivalent Sr(2)Sr8Mg4 cuboctahedra, edges with eight equivalent Sr(4)Sr8Mg4 cuboctahedra, faces with two equivalent Sr(1)Sr10Mg2 cuboctahedra, faces with two equivalent Sr(2)Sr8Mg4 cuboctahedra, faces with two equivalent Sr(4)Sr8Mg4 cuboctahedra, and faces with four equivalent Sr(3)Sr6Mg6 cuboctahedra. In the fourth Sr site, Sr(4) is bonded to two equivalent Sr(2), two equivalent Sr(4), four equivalent Sr(1), two equivalent Mg(1), and two equivalent Mg(2) atoms to form distorted SrSr8Mg4 cuboctahedra that share corners with six equivalent Sr(4)Sr8Mg4 cuboctahedra, edges with four equivalent Sr(1)Sr10Mg2 cuboctahedra, edges with eight equivalent Sr(3)Sr6Mg6 cuboctahedra, faces with two equivalent Sr(3)Sr6Mg6 cuboctahedra, faces with four equivalent Sr(1)Sr10Mg2 cuboctahedra, faces with four equivalent Sr(4)Sr8Mg4 cuboctahedra, and faces with six equivalent Sr(2)Sr8Mg4 cuboctahedra. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to two equivalent Sr(1), two equivalent Sr(4), and four equivalent Sr(3) atoms. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to two equivalent Sr(3), two equivalent Sr(4), and four equivalent Sr(2) atoms.
Sr2Mg1 crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to two equivalent Sr(1), two equivalent Sr(2), two equivalent Sr(3), four equivalent Sr(4), and two equivalent Mg(1) atoms to form distorted SrSr10Mg2 cuboctahedra that share corners with six equivalent Sr(1)Sr10Mg2 cuboctahedra, corners with six equivalent Sr(3)Sr6Mg6 cuboctahedra, corners with six equivalent Sr(2)Sr8Mg4 cuboctahedra, edges with three equivalent Sr(3)Sr6Mg6 cuboctahedra, edges with three equivalent Sr(2)Sr8Mg4 cuboctahedra, edges with four equivalent Sr(4)Sr8Mg4 cuboctahedra, faces with two equivalent Sr(3)Sr6Mg6 cuboctahedra, faces with two equivalent Sr(2)Sr8Mg4 cuboctahedra, faces with four equivalent Sr(1)Sr10Mg2 cuboctahedra, and faces with four equivalent Sr(4)Sr8Mg4 cuboctahedra. Both Sr(1)-Sr(1) bond lengths are 4.17 Å. Both Sr(1)-Sr(2) bond lengths are 4.13 Å. Both Sr(1)-Sr(3) bond lengths are 3.86 Å. All Sr(1)-Sr(4) bond lengths are 3.91 Å. Both Sr(1)-Mg(1) bond lengths are 3.81 Å. In the second Sr site, Sr(2) is bonded to two equivalent Sr(1), two equivalent Sr(2), two equivalent Sr(3), two equivalent Sr(4), and four equivalent Mg(2) atoms to form distorted SrSr8Mg4 cuboctahedra that share corners with six equivalent Sr(1)Sr10Mg2 cuboctahedra, corners with six equivalent Sr(3)Sr6Mg6 cuboctahedra, corners with six equivalent Sr(2)Sr8Mg4 cuboctahedra, edges with three equivalent Sr(1)Sr10Mg2 cuboctahedra, edges with three equivalent Sr(3)Sr6Mg6 cuboctahedra, faces with two equivalent Sr(1)Sr10Mg2 cuboctahedra, faces with two equivalent Sr(3)Sr6Mg6 cuboctahedra, faces with four equivalent Sr(2)Sr8Mg4 cuboctahedra, and faces with six equivalent Sr(4)Sr8Mg4 cuboctahedra. Both Sr(2)-Sr(2) bond lengths are 4.17 Å. Both Sr(2)-Sr(3) bond lengths are 3.89 Å. Both Sr(2)-Sr(4) bond lengths are 3.92 Å. All Sr(2)-Mg(2) bond lengths are 3.86 Å. In the third Sr site, Sr(3) is bonded to two equivalent Sr(1), two equivalent Sr(2), two equivalent Sr(3), two equivalent Mg(2), and four equivalent Mg(1) atoms to form distorted SrSr6Mg6 cuboctahedra that share corners with six equivalent Sr(1)Sr10Mg2 cuboctahedra, corners with six equivalent Sr(3)Sr6Mg6 cuboctahedra, corners with six equivalent Sr(2)Sr8Mg4 cuboctahedra, edges with three equivalent Sr(1)Sr10Mg2 cuboctahedra, edges with three equivalent Sr(2)Sr8Mg4 cuboctahedra, edges with eight equivalent Sr(4)Sr8Mg4 cuboctahedra, faces with two equivalent Sr(1)Sr10Mg2 cuboctahedra, faces with two equivalent Sr(2)Sr8Mg4 cuboctahedra, faces with two equivalent Sr(4)Sr8Mg4 cuboctahedra, and faces with four equivalent Sr(3)Sr6Mg6 cuboctahedra. Both Sr(3)-Sr(3) bond lengths are 4.17 Å. Both Sr(3)-Mg(2) bond lengths are 3.84 Å. All Sr(3)-Mg(1) bond lengths are 3.87 Å. In the fourth Sr site, Sr(4) is bonded to two equivalent Sr(2), two equivalent Sr(4), four equivalent Sr(1), two equivalent Mg(1), and two equivalent Mg(2) atoms to form distorted SrSr8Mg4 cuboctahedra that share corners with six equivalent Sr(4)Sr8Mg4 cuboctahedra, edges with four equivalent Sr(1)Sr10Mg2 cuboctahedra, edges with eight equivalent Sr(3)Sr6Mg6 cuboctahedra, faces with two equivalent Sr(3)Sr6Mg6 cuboctahedra, faces with four equivalent Sr(1)Sr10Mg2 cuboctahedra, faces with four equivalent Sr(4)Sr8Mg4 cuboctahedra, and faces with six equivalent Sr(2)Sr8Mg4 cuboctahedra. Both Sr(4)-Sr(4) bond lengths are 4.17 Å. Both Sr(4)-Mg(1) bond lengths are 3.97 Å. Both Sr(4)-Mg(2) bond lengths are 4.00 Å. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to two equivalent Sr(1), two equivalent Sr(4), and four equivalent Sr(3) atoms. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to two equivalent Sr(3), two equivalent Sr(4), and four equivalent Sr(2) atoms.