SrCa3(NBr)2 crystallizes in the monoclinic Pm space group. Sr(1) is bonded to one N(2), two equivalent N(1), one Br(2), and two equivalent Br(1) atoms to form distorted SrBr3N3 octahedra that share corners with six equivalent Ca(2)Br3N3 octahedra, edges with two equivalent Sr(1)Br3N3 octahedra, edges with two equivalent Ca(2)Br3N3 octahedra, and edges with four equivalent Ca(3)Br3N3 octahedra. The corner-sharing octahedral tilt angles range from 1-3°. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one N(1), two equivalent N(2), one Br(1), and two equivalent Br(2) atoms. In the second Ca site, Ca(2) is bonded to one N(2), two equivalent N(1), one Br(2), and two equivalent Br(1) atoms to form distorted CaBr3N3 octahedra that share corners with six equivalent Sr(1)Br3N3 octahedra, edges with two equivalent Sr(1)Br3N3 octahedra, edges with two equivalent Ca(2)Br3N3 octahedra, and edges with four equivalent Ca(3)Br3N3 octahedra. The corner-sharing octahedral tilt angles range from 1-3°. In the third Ca site, Ca(3) is bonded to one N(1), two equivalent N(2), one Br(1), and two equivalent Br(2) atoms to form distorted CaBr3N3 octahedra that share edges with two equivalent Ca(3)Br3N3 octahedra, edges with four equivalent Sr(1)Br3N3 octahedra, and edges with four equivalent Ca(2)Br3N3 octahedra. There are two inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Sr(1), one Ca(1), one Ca(3), and two equivalent Ca(2) atoms to form NSr2Ca4 octahedra that share edges with two equivalent N(1)Sr2Ca4 octahedra and edges with four equivalent N(2)SrCa5 octahedra. In the second N site, N(2) is bonded to one Sr(1), one Ca(2), two equivalent Ca(1), and two equivalent Ca(3) atoms to form NSrCa5 octahedra that share edges with two equivalent N(2)SrCa5 octahedra and edges with four equivalent N(1)Sr2Ca4 octahedra. There are two inequivalent Br sites. In the first Br site, Br(1) is bonded in a 6-coordinate geometry to two equivalent Sr(1), one Ca(1), one Ca(3), and two equivalent Ca(2) atoms. In the second Br site, Br(2) is bonded in a 6-coordinate geometry to one Sr(1), one Ca(2), two equivalent Ca(1), and two equivalent Ca(3) atoms.
SrCa3(NBr)2 crystallizes in the monoclinic Pm space group. Sr(1) is bonded to one N(2), two equivalent N(1), one Br(2), and two equivalent Br(1) atoms to form distorted SrBr3N3 octahedra that share corners with six equivalent Ca(2)Br3N3 octahedra, edges with two equivalent Sr(1)Br3N3 octahedra, edges with two equivalent Ca(2)Br3N3 octahedra, and edges with four equivalent Ca(3)Br3N3 octahedra. The corner-sharing octahedral tilt angles range from 1-3°. The Sr(1)-N(2) bond length is 2.61 Å. Both Sr(1)-N(1) bond lengths are 2.59 Å. The Sr(1)-Br(2) bond length is 3.15 Å. Both Sr(1)-Br(1) bond lengths are 3.18 Å. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one N(1), two equivalent N(2), one Br(1), and two equivalent Br(2) atoms. The Ca(1)-N(1) bond length is 2.46 Å. Both Ca(1)-N(2) bond lengths are 2.48 Å. The Ca(1)-Br(1) bond length is 3.26 Å. Both Ca(1)-Br(2) bond lengths are 3.23 Å. In the second Ca site, Ca(2) is bonded to one N(2), two equivalent N(1), one Br(2), and two equivalent Br(1) atoms to form distorted CaBr3N3 octahedra that share corners with six equivalent Sr(1)Br3N3 octahedra, edges with two equivalent Sr(1)Br3N3 octahedra, edges with two equivalent Ca(2)Br3N3 octahedra, and edges with four equivalent Ca(3)Br3N3 octahedra. The corner-sharing octahedral tilt angles range from 1-3°. The Ca(2)-N(2) bond length is 2.47 Å. Both Ca(2)-N(1) bond lengths are 2.48 Å. The Ca(2)-Br(2) bond length is 3.11 Å. Both Ca(2)-Br(1) bond lengths are 3.09 Å. In the third Ca site, Ca(3) is bonded to one N(1), two equivalent N(2), one Br(1), and two equivalent Br(2) atoms to form distorted CaBr3N3 octahedra that share edges with two equivalent Ca(3)Br3N3 octahedra, edges with four equivalent Sr(1)Br3N3 octahedra, and edges with four equivalent Ca(2)Br3N3 octahedra. The Ca(3)-N(1) bond length is 2.53 Å. Both Ca(3)-N(2) bond lengths are 2.51 Å. The Ca(3)-Br(1) bond length is 3.13 Å. Both Ca(3)-Br(2) bond lengths are 3.15 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Sr(1), one Ca(1), one Ca(3), and two equivalent Ca(2) atoms to form NSr2Ca4 octahedra that share edges with two equivalent N(1)Sr2Ca4 octahedra and edges with four equivalent N(2)SrCa5 octahedra. In the second N site, N(2) is bonded to one Sr(1), one Ca(2), two equivalent Ca(1), and two equivalent Ca(3) atoms to form NSrCa5 octahedra that share edges with two equivalent N(2)SrCa5 octahedra and edges with four equivalent N(1)Sr2Ca4 octahedra. There are two inequivalent Br sites. In the first Br site, Br(1) is bonded in a 6-coordinate geometry to two equivalent Sr(1), one Ca(1), one Ca(3), and two equivalent Ca(2) atoms. In the second Br site, Br(2) is bonded in a 6-coordinate geometry to one Sr(1), one Ca(2), two equivalent Ca(1), and two equivalent Ca(3) atoms.