Sr2MgV2(Si2O7)2 crystallizes in the triclinic P1 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(10), one O(11), one O(13), one O(14), one O(5), one O(6), one O(7), and two equivalent O(1) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(12), one O(13), one O(5), one O(6), one O(8), one O(9), and two equivalent O(2) atoms. Mg(1) is bonded to one O(11), one O(12), one O(6), one O(7), and one O(8) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  a cornercorner with one V(2)O5 trigonal bipyramid,  a cornercorner with one V(1)O4 trigonal pyramid,  an edgeedge with one Si(3)O4 tetrahedra, and  an edgeedge with one V(2)O5 trigonal bipyramid. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(10), one O(13), one O(5), and one O(8) atom to form distorted VO4 trigonal pyramids that share  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and  a cornercorner with one Mg(1)O5 trigonal bipyramid. In the second V site, V(2) is bonded to one O(11), one O(14), one O(6), one O(7), and one O(9) atom to form distorted VO5 trigonal bipyramids that share corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(13), one O(2), one O(3), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and corners with two equivalent V(1)O4 trigonal pyramids. In the second Si site, Si(2) is bonded to one O(1), one O(14), one O(3), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, and corners with two equivalent V(2)O5 trigonal bipyramids. In the third Si site, Si(3) is bonded to one O(1), one O(11), one O(4), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent V(2)O5 trigonal bipyramids, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. In the fourth Si site, Si(4) is bonded to one O(12), one O(2), one O(4), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, and  a cornercorner with one V(1)O4 trigonal pyramid. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Sr(1), one Si(2), and one Si(3) atom. In the second O site, O(2) is bonded in a distorted linear geometry to two equivalent Sr(2), one Si(1), and one Si(4) atom. In the third O site, O(3) is bonded in a linear geometry to one Si(1) and one Si(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one V(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Sr(1), one Sr(2), one Mg(1), one V(2), and one Si(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Sr(1), one Mg(1), one V(2), and one Si(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(2), one Mg(1), one V(1), and one Si(4) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Sr(2) and one V(2) atom. In the tenth O site, O(10) is bonded in a linear geometry to one Sr(1) and one V(1) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Sr(1), one Mg(1), one V(2), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Sr(2), one Mg(1), and one Si(4) atom. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one V(1), and one Si(1) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Sr(1), one V(2), and one Si(2) atom.
Sr2MgV2(Si2O7)2 crystallizes in the triclinic P1 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(10), one O(11), one O(13), one O(14), one O(5), one O(6), one O(7), and two equivalent O(1) atoms. The Sr(1)-O(10) bond length is 2.38 Å. The Sr(1)-O(11) bond length is 2.59 Å. The Sr(1)-O(13) bond length is 2.78 Å. The Sr(1)-O(14) bond length is 2.64 Å. The Sr(1)-O(5) bond length is 2.92 Å. The Sr(1)-O(6) bond length is 3.13 Å. The Sr(1)-O(7) bond length is 2.63 Å. There is one shorter (2.83 Å) and one longer (2.92 Å) Sr(1)-O(1) bond length. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(12), one O(13), one O(5), one O(6), one O(8), one O(9), and two equivalent O(2) atoms. The Sr(2)-O(12) bond length is 2.67 Å. The Sr(2)-O(13) bond length is 2.54 Å. The Sr(2)-O(5) bond length is 2.53 Å. The Sr(2)-O(6) bond length is 2.88 Å. The Sr(2)-O(8) bond length is 2.76 Å. The Sr(2)-O(9) bond length is 2.25 Å. There is one shorter (2.74 Å) and one longer (2.84 Å) Sr(2)-O(2) bond length. Mg(1) is bonded to one O(11), one O(12), one O(6), one O(7), and one O(8) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra,  a cornercorner with one V(2)O5 trigonal bipyramid,  a cornercorner with one V(1)O4 trigonal pyramid,  an edgeedge with one Si(3)O4 tetrahedra, and  an edgeedge with one V(2)O5 trigonal bipyramid. The Mg(1)-O(11) bond length is 2.13 Å. The Mg(1)-O(12) bond length is 2.02 Å. The Mg(1)-O(6) bond length is 2.10 Å. The Mg(1)-O(7) bond length is 2.05 Å. The Mg(1)-O(8) bond length is 2.09 Å. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(10), one O(13), one O(5), and one O(8) atom to form distorted VO4 trigonal pyramids that share  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and  a cornercorner with one Mg(1)O5 trigonal bipyramid. The V(1)-O(10) bond length is 1.73 Å. The V(1)-O(13) bond length is 2.06 Å. The V(1)-O(5) bond length is 2.09 Å. The V(1)-O(8) bond length is 2.13 Å. In the second V site, V(2) is bonded to one O(11), one O(14), one O(6), one O(7), and one O(9) atom to form distorted VO5 trigonal bipyramids that share corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The V(2)-O(11) bond length is 2.04 Å. The V(2)-O(14) bond length is 2.03 Å. The V(2)-O(6) bond length is 2.30 Å. The V(2)-O(7) bond length is 2.28 Å. The V(2)-O(9) bond length is 1.76 Å. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(13), one O(2), one O(3), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and corners with two equivalent V(1)O4 trigonal pyramids. The Si(1)-O(13) bond length is 1.63 Å. The Si(1)-O(2) bond length is 1.68 Å. The Si(1)-O(3) bond length is 1.61 Å. The Si(1)-O(5) bond length is 1.63 Å. In the second Si site, Si(2) is bonded to one O(1), one O(14), one O(3), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, and corners with two equivalent V(2)O5 trigonal bipyramids. The Si(2)-O(1) bond length is 1.67 Å. The Si(2)-O(14) bond length is 1.63 Å. The Si(2)-O(3) bond length is 1.61 Å. The Si(2)-O(6) bond length is 1.65 Å. In the third Si site, Si(3) is bonded to one O(1), one O(11), one O(4), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent V(2)O5 trigonal bipyramids, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The Si(3)-O(1) bond length is 1.67 Å. The Si(3)-O(11) bond length is 1.65 Å. The Si(3)-O(4) bond length is 1.62 Å. The Si(3)-O(7) bond length is 1.64 Å. In the fourth Si site, Si(4) is bonded to one O(12), one O(2), one O(4), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, and  a cornercorner with one V(1)O4 trigonal pyramid. The Si(4)-O(12) bond length is 1.61 Å. The Si(4)-O(2) bond length is 1.68 Å. The Si(4)-O(4) bond length is 1.64 Å. The Si(4)-O(8) bond length is 1.66 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Sr(1), one Si(2), and one Si(3) atom. In the second O site, O(2) is bonded in a distorted linear geometry to two equivalent Sr(2), one Si(1), and one Si(4) atom. In the third O site, O(3) is bonded in a linear geometry to one Si(1) and one Si(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one V(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Sr(1), one Sr(2), one Mg(1), one V(2), and one Si(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Sr(1), one Mg(1), one V(2), and one Si(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(2), one Mg(1), one V(1), and one Si(4) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Sr(2) and one V(2) atom. In the tenth O site, O(10) is bonded in a linear geometry to one Sr(1) and one V(1) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Sr(1), one Mg(1), one V(2), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Sr(2), one Mg(1), and one Si(4) atom. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one V(1), and one Si(1) atom. In the fourteenth O site, O(14) is bonded in a 3-coordinate geometry to one Sr(1), one V(2), and one Si(2) atom.