Sr4C2N5 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to one C(1), one N(1), two equivalent N(3), and four equivalent N(2) atoms. In the second Sr site, Sr(2) is bonded in a 5-coordinate geometry to one N(1), one N(2), one N(4), and two equivalent N(3) atoms. In the third Sr site, Sr(3) is bonded in a 6-coordinate geometry to one N(1), two equivalent N(4), and three equivalent N(5) atoms. In the fourth Sr site, Sr(4) is bonded in a 6-coordinate geometry to one N(3), one N(5), two equivalent N(1), and two equivalent N(4) atoms. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one Sr(1), one N(1), one N(2), and one N(3) atom. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one N(4) and one N(5) atom. There are five inequivalent N sites. In the first N site, N(3) is bonded in a 1-coordinate geometry to one Sr(4), two equivalent Sr(1), two equivalent Sr(2), and one C(1) atom. In the second N site, N(4) is bonded to one Sr(2), two equivalent Sr(3), two equivalent Sr(4), and one C(2) atom to form distorted corner-sharing NSr5C octahedra. The corner-sharing octahedral tilt angles range from 36-43°. In the third N site, N(5) is bonded in a 1-coordinate geometry to one Sr(4), three equivalent Sr(3), and one C(2) atom. In the fourth N site, N(1) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), two equivalent Sr(4), and one C(1) atom. In the fifth N site, N(2) is bonded in a 6-coordinate geometry to one Sr(2), four equivalent Sr(1), and one C(1) atom.
Sr4C2N5 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to one C(1), one N(1), two equivalent N(3), and four equivalent N(2) atoms. The Sr(1)-C(1) bond length is 2.74 Å. The Sr(1)-N(1) bond length is 2.70 Å. There is one shorter (2.81 Å) and one longer (2.92 Å) Sr(1)-N(3) bond length. There are a spread of Sr(1)-N(2) bond distances ranging from 2.58-2.73 Å. In the second Sr site, Sr(2) is bonded in a 5-coordinate geometry to one N(1), one N(2), one N(4), and two equivalent N(3) atoms. The Sr(2)-N(1) bond length is 2.92 Å. The Sr(2)-N(2) bond length is 2.72 Å. The Sr(2)-N(4) bond length is 2.51 Å. There is one shorter (2.54 Å) and one longer (2.59 Å) Sr(2)-N(3) bond length. In the third Sr site, Sr(3) is bonded in a 6-coordinate geometry to one N(1), two equivalent N(4), and three equivalent N(5) atoms. The Sr(3)-N(1) bond length is 2.93 Å. There is one shorter (2.66 Å) and one longer (2.70 Å) Sr(3)-N(4) bond length. There are a spread of Sr(3)-N(5) bond distances ranging from 2.63-2.68 Å. In the fourth Sr site, Sr(4) is bonded in a 6-coordinate geometry to one N(3), one N(5), two equivalent N(1), and two equivalent N(4) atoms. The Sr(4)-N(3) bond length is 2.66 Å. The Sr(4)-N(5) bond length is 2.67 Å. There is one shorter (2.63 Å) and one longer (2.79 Å) Sr(4)-N(1) bond length. There is one shorter (2.64 Å) and one longer (2.80 Å) Sr(4)-N(4) bond length. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one Sr(1), one N(1), one N(2), and one N(3) atom. The C(1)-N(1) bond length is 1.40 Å. The C(1)-N(2) bond length is 1.39 Å. The C(1)-N(3) bond length is 1.41 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one N(4) and one N(5) atom. The C(2)-N(4) bond length is 1.34 Å. The C(2)-N(5) bond length is 1.34 Å. There are five inequivalent N sites. In the first N site, N(3) is bonded in a 1-coordinate geometry to one Sr(4), two equivalent Sr(1), two equivalent Sr(2), and one C(1) atom. In the second N site, N(4) is bonded to one Sr(2), two equivalent Sr(3), two equivalent Sr(4), and one C(2) atom to form distorted corner-sharing NSr5C octahedra. The corner-sharing octahedral tilt angles range from 36-43°. In the third N site, N(5) is bonded in a 1-coordinate geometry to one Sr(4), three equivalent Sr(3), and one C(2) atom. In the fourth N site, N(1) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), two equivalent Sr(4), and one C(1) atom. In the fifth N site, N(2) is bonded in a 6-coordinate geometry to one Sr(2), four equivalent Sr(1), and one C(1) atom.