Ca11(CrN5)2 crystallizes in the tetragonal P4_2/mnm space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent N(4) and four equivalent N(1) atoms to form CaN6 octahedra that share edges with two equivalent Ca(1)N6 octahedra and edges with eight equivalent Ca(2)N5 trigonal bipyramids. In the second Ca site, Ca(2) is bonded to one N(1), two equivalent N(2), and two equivalent N(4) atoms to form distorted CaN5 trigonal bipyramids that share corners with three equivalent Ca(2)N5 trigonal bipyramids, edges with two equivalent Ca(1)N6 octahedra, and edges with three equivalent Ca(2)N5 trigonal bipyramids. In the third Ca site, Ca(3) is bonded in a rectangular see-saw-like geometry to two equivalent N(1) and two equivalent N(3) atoms. In the fourth Ca site, Ca(4) is bonded in a 4-coordinate geometry to one N(3) and three equivalent N(2) atoms. Cr(1) is bonded in a linear geometry to one N(3) and one N(4) atom. There are four inequivalent N sites. In the first N site, N(3) is bonded to two equivalent Ca(3), two equivalent Ca(4), and one Cr(1) atom to form distorted NCa4Cr trigonal bipyramids that share  a cornercorner with one N(4)Ca5Cr octahedra, corners with two equivalent N(1)Ca6 octahedra, corners with six equivalent N(2)Ca5 square pyramids, corners with two equivalent N(3)Ca4Cr trigonal bipyramids, and  an edgeedge with one N(1)Ca6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the second N site, N(4) is bonded to one Ca(1), four equivalent Ca(2), and one Cr(1) atom to form NCa5Cr octahedra that share  a cornercorner with one N(4)Ca5Cr octahedra, corners with four equivalent N(2)Ca5 square pyramids,  a cornercorner with one N(3)Ca4Cr trigonal bipyramid, edges with two equivalent N(4)Ca5Cr octahedra, edges with four equivalent N(1)Ca6 octahedra, and edges with two equivalent N(2)Ca5 square pyramids. The corner-sharing octahedra are not tilted. In the third N site, N(1) is bonded to two equivalent Ca(1), two equivalent Ca(2), and two equivalent Ca(3) atoms to form NCa6 octahedra that share corners with two equivalent N(1)Ca6 octahedra, corners with four equivalent N(2)Ca5 square pyramids, corners with two equivalent N(3)Ca4Cr trigonal bipyramids, edges with three equivalent N(1)Ca6 octahedra, edges with four equivalent N(4)Ca5Cr octahedra, and  an edgeedge with one N(3)Ca4Cr trigonal bipyramid. The corner-sharing octahedra are not tilted. In the fourth N site, N(2) is bonded to two equivalent Ca(2) and three equivalent Ca(4) atoms to form distorted NCa5 square pyramids that share corners with two equivalent N(4)Ca5Cr octahedra, corners with two equivalent N(1)Ca6 octahedra, corners with four equivalent N(2)Ca5 square pyramids, corners with three equivalent N(3)Ca4Cr trigonal bipyramids,  an edgeedge with one N(4)Ca5Cr octahedra, and edges with two equivalent N(2)Ca5 square pyramids. The corner-sharing octahedral tilt angles range from 20-69°.
Ca11(CrN5)2 crystallizes in the tetragonal P4_2/mnm space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent N(4) and four equivalent N(1) atoms to form CaN6 octahedra that share edges with two equivalent Ca(1)N6 octahedra and edges with eight equivalent Ca(2)N5 trigonal bipyramids. Both Ca(1)-N(4) bond lengths are 2.48 Å. All Ca(1)-N(1) bond lengths are 2.50 Å. In the second Ca site, Ca(2) is bonded to one N(1), two equivalent N(2), and two equivalent N(4) atoms to form distorted CaN5 trigonal bipyramids that share corners with three equivalent Ca(2)N5 trigonal bipyramids, edges with two equivalent Ca(1)N6 octahedra, and edges with three equivalent Ca(2)N5 trigonal bipyramids. The Ca(2)-N(1) bond length is 2.44 Å. Both Ca(2)-N(2) bond lengths are 2.53 Å. Both Ca(2)-N(4) bond lengths are 2.58 Å. In the third Ca site, Ca(3) is bonded in a rectangular see-saw-like geometry to two equivalent N(1) and two equivalent N(3) atoms. Both Ca(3)-N(1) bond lengths are 2.42 Å. Both Ca(3)-N(3) bond lengths are 2.28 Å. In the fourth Ca site, Ca(4) is bonded in a 4-coordinate geometry to one N(3) and three equivalent N(2) atoms. The Ca(4)-N(3) bond length is 2.98 Å. There are two shorter (2.41 Å) and one longer (2.48 Å) Ca(4)-N(2) bond length. Cr(1) is bonded in a linear geometry to one N(3) and one N(4) atom. The Cr(1)-N(3) bond length is 1.72 Å. The Cr(1)-N(4) bond length is 1.75 Å. There are four inequivalent N sites. In the first N site, N(3) is bonded to two equivalent Ca(3), two equivalent Ca(4), and one Cr(1) atom to form distorted NCa4Cr trigonal bipyramids that share  a cornercorner with one N(4)Ca5Cr octahedra, corners with two equivalent N(1)Ca6 octahedra, corners with six equivalent N(2)Ca5 square pyramids, corners with two equivalent N(3)Ca4Cr trigonal bipyramids, and  an edgeedge with one N(1)Ca6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the second N site, N(4) is bonded to one Ca(1), four equivalent Ca(2), and one Cr(1) atom to form NCa5Cr octahedra that share  a cornercorner with one N(4)Ca5Cr octahedra, corners with four equivalent N(2)Ca5 square pyramids,  a cornercorner with one N(3)Ca4Cr trigonal bipyramid, edges with two equivalent N(4)Ca5Cr octahedra, edges with four equivalent N(1)Ca6 octahedra, and edges with two equivalent N(2)Ca5 square pyramids. The corner-sharing octahedra are not tilted. In the third N site, N(1) is bonded to two equivalent Ca(1), two equivalent Ca(2), and two equivalent Ca(3) atoms to form NCa6 octahedra that share corners with two equivalent N(1)Ca6 octahedra, corners with four equivalent N(2)Ca5 square pyramids, corners with two equivalent N(3)Ca4Cr trigonal bipyramids, edges with three equivalent N(1)Ca6 octahedra, edges with four equivalent N(4)Ca5Cr octahedra, and  an edgeedge with one N(3)Ca4Cr trigonal bipyramid. The corner-sharing octahedra are not tilted. In the fourth N site, N(2) is bonded to two equivalent Ca(2) and three equivalent Ca(4) atoms to form distorted NCa5 square pyramids that share corners with two equivalent N(4)Ca5Cr octahedra, corners with two equivalent N(1)Ca6 octahedra, corners with four equivalent N(2)Ca5 square pyramids, corners with three equivalent N(3)Ca4Cr trigonal bipyramids,  an edgeedge with one N(4)Ca5Cr octahedra, and edges with two equivalent N(2)Ca5 square pyramids. The corner-sharing octahedral tilt angles range from 20-69°.