Sr3(AsO4)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to one O(3), one O(4), one O(5), one O(6), two equivalent O(1), and two equivalent O(2) atoms. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(5), one O(7), and two equivalent O(6) atoms. In the third Sr site, Sr(3) is bonded in a 7-coordinate geometry to one O(2), one O(5), one O(7), two equivalent O(4), and two equivalent O(8) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. In the second As site, As(2) is bonded in a tetrahedral geometry to one O(5), one O(6), one O(7), and one O(8) atom. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Sr(2), one Sr(3), and one As(2) atom. In the second O site, O(8) is bonded in a 3-coordinate geometry to two equivalent Sr(3) and one As(2) atom. In the third O site, O(1) is bonded in a 4-coordinate geometry to one Sr(2), two equivalent Sr(1), and one As(1) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Sr(3), two equivalent Sr(1), and one As(1) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to one Sr(1), one Sr(2), and one As(1) atom. In the sixth O site, O(4) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Sr(3), and one As(1) atom. In the seventh O site, O(5) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), and one As(2) atom. In the eighth O site, O(6) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Sr(2), and one As(2) atom.
Sr3(AsO4)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to one O(3), one O(4), one O(5), one O(6), two equivalent O(1), and two equivalent O(2) atoms. The Sr(1)-O(3) bond length is 2.90 Å. The Sr(1)-O(4) bond length is 2.81 Å. The Sr(1)-O(5) bond length is 2.86 Å. The Sr(1)-O(6) bond length is 2.63 Å. There is one shorter (2.53 Å) and one longer (2.77 Å) Sr(1)-O(1) bond length. There is one shorter (2.47 Å) and one longer (2.72 Å) Sr(1)-O(2) bond length. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(5), one O(7), and two equivalent O(6) atoms. The Sr(2)-O(1) bond length is 2.53 Å. The Sr(2)-O(3) bond length is 2.50 Å. The Sr(2)-O(5) bond length is 2.46 Å. The Sr(2)-O(7) bond length is 2.52 Å. There is one shorter (2.51 Å) and one longer (3.12 Å) Sr(2)-O(6) bond length. In the third Sr site, Sr(3) is bonded in a 7-coordinate geometry to one O(2), one O(5), one O(7), two equivalent O(4), and two equivalent O(8) atoms. The Sr(3)-O(2) bond length is 2.92 Å. The Sr(3)-O(5) bond length is 3.05 Å. The Sr(3)-O(7) bond length is 2.53 Å. There is one shorter (2.45 Å) and one longer (2.60 Å) Sr(3)-O(4) bond length. There is one shorter (2.56 Å) and one longer (2.67 Å) Sr(3)-O(8) bond length. There are two inequivalent As sites. In the first As site, As(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. The As(1)-O(1) bond length is 1.73 Å. The As(1)-O(2) bond length is 1.73 Å. The As(1)-O(3) bond length is 1.71 Å. The As(1)-O(4) bond length is 1.73 Å. In the second As site, As(2) is bonded in a tetrahedral geometry to one O(5), one O(6), one O(7), and one O(8) atom. The As(2)-O(5) bond length is 1.73 Å. The As(2)-O(6) bond length is 1.73 Å. The As(2)-O(7) bond length is 1.72 Å. The As(2)-O(8) bond length is 1.73 Å. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Sr(2), one Sr(3), and one As(2) atom. In the second O site, O(8) is bonded in a 3-coordinate geometry to two equivalent Sr(3) and one As(2) atom. In the third O site, O(1) is bonded in a 4-coordinate geometry to one Sr(2), two equivalent Sr(1), and one As(1) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Sr(3), two equivalent Sr(1), and one As(1) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to one Sr(1), one Sr(2), and one As(1) atom. In the sixth O site, O(4) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Sr(3), and one As(1) atom. In the seventh O site, O(5) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), and one As(2) atom. In the eighth O site, O(6) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Sr(2), and one As(2) atom.