SrSiAl2O3N2 crystallizes in the orthorhombic P2_12_12_1 space group. Sr(1) is bonded in a 9-coordinate geometry to one N(1), two equivalent N(2), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one N(2), one O(1), one O(2), and one O(3) atom to form AlNO3 tetrahedra that share corners with two equivalent Si(1)N3O tetrahedra and corners with three equivalent Al(2)N2O2 tetrahedra. In the second Al site, Al(2) is bonded to one N(1), one N(2), one O(1), and one O(3) atom to form AlN2O2 tetrahedra that share corners with three equivalent Al(1)NO3 tetrahedra and corners with three equivalent Si(1)N3O tetrahedra. Si(1) is bonded to one N(2), two equivalent N(1), and one O(2) atom to form SiN3O tetrahedra that share corners with two equivalent Al(1)NO3 tetrahedra, corners with two equivalent Si(1)N3O tetrahedra, and corners with three equivalent Al(2)N2O2 tetrahedra. There are two inequivalent N sites. In the first N site, N(1) is bonded in a 3-coordinate geometry to one Sr(1), one Al(2), and two equivalent Si(1) atoms. In the second N site, N(2) is bonded in a distorted trigonal planar geometry to two equivalent Sr(1), one Al(1), one Al(2), and one Si(1) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), one Al(1), and one Al(2) atom to form distorted corner-sharing OSr2Al2 tetrahedra. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Sr(1), one Al(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Sr(1), one Al(1), and one Al(2) atom.
SrSiAl2O3N2 crystallizes in the orthorhombic P2_12_12_1 space group. Sr(1) is bonded in a 9-coordinate geometry to one N(1), two equivalent N(2), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. The Sr(1)-N(1) bond length is 2.84 Å. There is one shorter (3.06 Å) and one longer (3.23 Å) Sr(1)-N(2) bond length. There is one shorter (2.52 Å) and one longer (2.75 Å) Sr(1)-O(1) bond length. There is one shorter (2.74 Å) and one longer (3.23 Å) Sr(1)-O(2) bond length. There is one shorter (2.66 Å) and one longer (2.95 Å) Sr(1)-O(3) bond length. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one N(2), one O(1), one O(2), and one O(3) atom to form AlNO3 tetrahedra that share corners with two equivalent Si(1)N3O tetrahedra and corners with three equivalent Al(2)N2O2 tetrahedra. The Al(1)-N(2) bond length is 1.86 Å. The Al(1)-O(1) bond length is 1.77 Å. The Al(1)-O(2) bond length is 1.78 Å. The Al(1)-O(3) bond length is 1.76 Å. In the second Al site, Al(2) is bonded to one N(1), one N(2), one O(1), and one O(3) atom to form AlN2O2 tetrahedra that share corners with three equivalent Al(1)NO3 tetrahedra and corners with three equivalent Si(1)N3O tetrahedra. The Al(2)-N(1) bond length is 1.88 Å. The Al(2)-N(2) bond length is 1.86 Å. The Al(2)-O(1) bond length is 1.79 Å. The Al(2)-O(3) bond length is 1.77 Å. Si(1) is bonded to one N(2), two equivalent N(1), and one O(2) atom to form SiN3O tetrahedra that share corners with two equivalent Al(1)NO3 tetrahedra, corners with two equivalent Si(1)N3O tetrahedra, and corners with three equivalent Al(2)N2O2 tetrahedra. The Si(1)-N(2) bond length is 1.73 Å. There is one shorter (1.74 Å) and one longer (1.75 Å) Si(1)-N(1) bond length. The Si(1)-O(2) bond length is 1.68 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a 3-coordinate geometry to one Sr(1), one Al(2), and two equivalent Si(1) atoms. In the second N site, N(2) is bonded in a distorted trigonal planar geometry to two equivalent Sr(1), one Al(1), one Al(2), and one Si(1) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), one Al(1), and one Al(2) atom to form distorted corner-sharing OSr2Al2 tetrahedra. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Sr(1), one Al(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Sr(1), one Al(1), and one Al(2) atom.