SrNd4Si3O13 crystallizes in the hexagonal P6_3 space group. Sr(1) is bonded in a 9-coordinate geometry to three equivalent O(2), three equivalent O(3), and three equivalent O(4) atoms. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(3), and three equivalent O(4) atoms. In the second Nd site, Nd(2) is bonded in a 7-coordinate geometry to one O(3), one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are five inequivalent O sites. In the first O site, O(4) is bonded in a 4-coordinate geometry to one Sr(1), one Nd(1), one Nd(2), and one Si(1) atom. In the second O site, O(5) is bonded in a trigonal planar geometry to three equivalent Nd(2) atoms. In the third O site, O(1) is bonded in a 1-coordinate geometry to one Nd(1), two equivalent Nd(2), and one Si(1) atom. In the fourth O site, O(2) is bonded in a 1-coordinate geometry to one Sr(1), two equivalent Nd(2), and one Si(1) atom. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Sr(1), one Nd(1), one Nd(2), and one Si(1) atom.
SrNd4Si3O13 crystallizes in the hexagonal P6_3 space group. Sr(1) is bonded in a 9-coordinate geometry to three equivalent O(2), three equivalent O(3), and three equivalent O(4) atoms. All Sr(1)-O(2) bond lengths are 2.90 Å. All Sr(1)-O(3) bond lengths are 2.53 Å. All Sr(1)-O(4) bond lengths are 2.59 Å. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(3), and three equivalent O(4) atoms. All Nd(1)-O(1) bond lengths are 2.87 Å. All Nd(1)-O(3) bond lengths are 2.44 Å. All Nd(1)-O(4) bond lengths are 2.49 Å. In the second Nd site, Nd(2) is bonded in a 7-coordinate geometry to one O(3), one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms. The Nd(2)-O(3) bond length is 2.69 Å. The Nd(2)-O(4) bond length is 2.47 Å. The Nd(2)-O(5) bond length is 2.30 Å. There is one shorter (2.43 Å) and one longer (2.56 Å) Nd(2)-O(1) bond length. There is one shorter (2.44 Å) and one longer (2.52 Å) Nd(2)-O(2) bond length. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Si(1)-O(1) bond length is 1.66 Å. The Si(1)-O(2) bond length is 1.65 Å. The Si(1)-O(3) bond length is 1.64 Å. The Si(1)-O(4) bond length is 1.65 Å. There are five inequivalent O sites. In the first O site, O(4) is bonded in a 4-coordinate geometry to one Sr(1), one Nd(1), one Nd(2), and one Si(1) atom. In the second O site, O(5) is bonded in a trigonal planar geometry to three equivalent Nd(2) atoms. In the third O site, O(1) is bonded in a 1-coordinate geometry to one Nd(1), two equivalent Nd(2), and one Si(1) atom. In the fourth O site, O(2) is bonded in a 1-coordinate geometry to one Sr(1), two equivalent Nd(2), and one Si(1) atom. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Sr(1), one Nd(1), one Nd(2), and one Si(1) atom.