CaHf8(N2O)4 crystallizes in the triclinic P1 space group. Ca(1) is bonded to one N(5), one N(6), one N(8), and one O(3) atom to form CaN3O tetrahedra that share  a cornercorner with one Hf(1)N4O2 octahedra,  a cornercorner with one Hf(7)N4O2 octahedra, corners with three equivalent Hf(2)N3O tetrahedra, and corners with three equivalent Hf(3)N3O tetrahedra. The corner-sharing octahedral tilt angles range from 64-67°. There are eight inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to one N(1), one N(2), one N(4), one N(6), one O(1), and one O(2) atom to form distorted HfN4O2 octahedra that share corners with three equivalent Hf(5)N4O2 octahedra,  a cornercorner with one Ca(1)N3O tetrahedra,  a cornercorner with one Hf(3)N3O tetrahedra, edges with three equivalent Hf(7)N4O2 octahedra, and  a faceface with one Hf(8)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 38-52°. In the second Hf site, Hf(2) is bonded to one N(3), one N(5), one N(8), and one O(3) atom to form HfN3O tetrahedra that share  a cornercorner with one Hf(5)N4O2 octahedra,  a cornercorner with one Hf(8)N4O2 octahedra, corners with three equivalent Ca(1)N3O tetrahedra, and corners with three equivalent Hf(3)N3O tetrahedra. The corner-sharing octahedral tilt angles range from 63-66°. In the third Hf site, Hf(3) is bonded to one N(2), one N(5), one N(8), and one O(3) atom to form HfN3O tetrahedra that share  a cornercorner with one Hf(1)N4O2 octahedra,  a cornercorner with one Hf(7)N4O2 octahedra, corners with three equivalent Ca(1)N3O tetrahedra, and corners with three equivalent Hf(2)N3O tetrahedra. The corner-sharing octahedral tilt angles range from 62-63°. In the fourth Hf site, Hf(4) is bonded in a 6-coordinate geometry to one N(1), one N(3), one N(4), one N(7), one O(2), and one O(4) atom. In the fifth Hf site, Hf(5) is bonded to one N(1), one N(3), one N(4), one N(7), one O(2), and one O(4) atom to form distorted HfN4O2 octahedra that share corners with three equivalent Hf(1)N4O2 octahedra,  a cornercorner with one Hf(2)N3O tetrahedra, edges with three equivalent Hf(8)N4O2 octahedra, and  a faceface with one Hf(7)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 38-52°. In the sixth Hf site, Hf(6) is bonded in a 6-coordinate geometry to one N(1), one N(2), one N(4), one N(6), one O(1), and one O(2) atom. In the seventh Hf site, Hf(7) is bonded to one N(1), one N(2), one N(4), one N(6), one O(1), and one O(2) atom to form distorted HfN4O2 octahedra that share corners with three equivalent Hf(8)N4O2 octahedra,  a cornercorner with one Ca(1)N3O tetrahedra,  a cornercorner with one Hf(3)N3O tetrahedra, edges with three equivalent Hf(1)N4O2 octahedra, and  a faceface with one Hf(5)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 41-50°. In the eighth Hf site, Hf(8) is bonded to one N(1), one N(3), one N(4), one N(7), one O(2), and one O(4) atom to form distorted HfN4O2 octahedra that share corners with three equivalent Hf(7)N4O2 octahedra,  a cornercorner with one Hf(2)N3O tetrahedra, edges with three equivalent Hf(5)N4O2 octahedra, and  a faceface with one Hf(1)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 41-50°. There are eight inequivalent N sites. In the first N site, N(1) is bonded to one Hf(1), one Hf(4), one Hf(5), one Hf(6), one Hf(7), and one Hf(8) atom to form distorted NHf6 pentagonal pyramids that share  a cornercorner with one N(6)CaHf3 tetrahedra,  a cornercorner with one N(2)Hf4 tetrahedra,  a cornercorner with one N(3)Hf4 tetrahedra, edges with three equivalent N(4)Hf6 pentagonal pyramids,  an edgeedge with one N(6)CaHf3 tetrahedra,  an edgeedge with one N(2)Hf4 tetrahedra, and  an edgeedge with one N(3)Hf4 tetrahedra. In the second N site, N(2) is bonded to one Hf(1), one Hf(3), one Hf(6), and one Hf(7) atom to form NHf4 tetrahedra that share  a cornercorner with one N(1)Hf6 pentagonal pyramid,  a cornercorner with one N(4)Hf6 pentagonal pyramid, corners with three equivalent N(6)CaHf3 tetrahedra,  an edgeedge with one N(1)Hf6 pentagonal pyramid, and  an edgeedge with one N(4)Hf6 pentagonal pyramid. In the third N site, N(3) is bonded to one Hf(2), one Hf(4), one Hf(5), and one Hf(8) atom to form a mixture of corner and edge-sharing NHf4 tetrahedra. In the fourth N site, N(4) is bonded to one Hf(1), one Hf(4), one Hf(5), one Hf(6), one Hf(7), and one Hf(8) atom to form distorted NHf6 pentagonal pyramids that share  a cornercorner with one N(6)CaHf3 tetrahedra,  a cornercorner with one N(2)Hf4 tetrahedra,  a cornercorner with one N(3)Hf4 tetrahedra, edges with three equivalent N(1)Hf6 pentagonal pyramids,  an edgeedge with one N(6)CaHf3 tetrahedra,  an edgeedge with one N(2)Hf4 tetrahedra, and  an edgeedge with one N(3)Hf4 tetrahedra. In the fifth N site, N(5) is bonded in a trigonal planar geometry to one Ca(1), one Hf(2), and one Hf(3) atom. In the sixth N site, N(6) is bonded to one Ca(1), one Hf(1), one Hf(6), and one Hf(7) atom to form NCaHf3 tetrahedra that share  a cornercorner with one N(1)Hf6 pentagonal pyramid,  a cornercorner with one N(4)Hf6 pentagonal pyramid, corners with three equivalent N(2)Hf4 tetrahedra,  an edgeedge with one N(1)Hf6 pentagonal pyramid, and  an edgeedge with one N(4)Hf6 pentagonal pyramid. In the seventh N site, N(7) is bonded in a trigonal non-coplanar geometry to one Hf(4), one Hf(5), and one Hf(8) atom. In the eighth N site, N(8) is bonded in a distorted trigonal planar geometry to one Ca(1), one Hf(2), and one Hf(3) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Hf(1), one Hf(6), and one Hf(7) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Hf(1), one Hf(4), one Hf(5), one Hf(6), one Hf(7), and one Hf(8) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ca(1), one Hf(2), and one Hf(3) atom. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Hf(4), one Hf(5), and one Hf(8) atom.
CaHf8(N2O)4 crystallizes in the triclinic P1 space group. Ca(1) is bonded to one N(5), one N(6), one N(8), and one O(3) atom to form CaN3O tetrahedra that share  a cornercorner with one Hf(1)N4O2 octahedra,  a cornercorner with one Hf(7)N4O2 octahedra, corners with three equivalent Hf(2)N3O tetrahedra, and corners with three equivalent Hf(3)N3O tetrahedra. The corner-sharing octahedral tilt angles range from 64-67°. The Ca(1)-N(5) bond length is 2.24 Å. The Ca(1)-N(6) bond length is 2.43 Å. The Ca(1)-N(8) bond length is 2.24 Å. The Ca(1)-O(3) bond length is 2.22 Å. There are eight inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to one N(1), one N(2), one N(4), one N(6), one O(1), and one O(2) atom to form distorted HfN4O2 octahedra that share corners with three equivalent Hf(5)N4O2 octahedra,  a cornercorner with one Ca(1)N3O tetrahedra,  a cornercorner with one Hf(3)N3O tetrahedra, edges with three equivalent Hf(7)N4O2 octahedra, and  a faceface with one Hf(8)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 38-52°. The Hf(1)-N(1) bond length is 2.42 Å. The Hf(1)-N(2) bond length is 2.19 Å. The Hf(1)-N(4) bond length is 2.46 Å. The Hf(1)-N(6) bond length is 2.11 Å. The Hf(1)-O(1) bond length is 2.06 Å. The Hf(1)-O(2) bond length is 2.30 Å. In the second Hf site, Hf(2) is bonded to one N(3), one N(5), one N(8), and one O(3) atom to form HfN3O tetrahedra that share  a cornercorner with one Hf(5)N4O2 octahedra,  a cornercorner with one Hf(8)N4O2 octahedra, corners with three equivalent Ca(1)N3O tetrahedra, and corners with three equivalent Hf(3)N3O tetrahedra. The corner-sharing octahedral tilt angles range from 63-66°. The Hf(2)-N(3) bond length is 2.14 Å. The Hf(2)-N(5) bond length is 1.97 Å. The Hf(2)-N(8) bond length is 1.97 Å. The Hf(2)-O(3) bond length is 1.99 Å. In the third Hf site, Hf(3) is bonded to one N(2), one N(5), one N(8), and one O(3) atom to form HfN3O tetrahedra that share  a cornercorner with one Hf(1)N4O2 octahedra,  a cornercorner with one Hf(7)N4O2 octahedra, corners with three equivalent Ca(1)N3O tetrahedra, and corners with three equivalent Hf(2)N3O tetrahedra. The corner-sharing octahedral tilt angles range from 62-63°. The Hf(3)-N(2) bond length is 2.14 Å. The Hf(3)-N(5) bond length is 1.97 Å. The Hf(3)-N(8) bond length is 1.96 Å. The Hf(3)-O(3) bond length is 1.98 Å. In the fourth Hf site, Hf(4) is bonded in a 6-coordinate geometry to one N(1), one N(3), one N(4), one N(7), one O(2), and one O(4) atom. The Hf(4)-N(1) bond length is 2.34 Å. The Hf(4)-N(3) bond length is 2.08 Å. The Hf(4)-N(4) bond length is 2.29 Å. The Hf(4)-N(7) bond length is 2.07 Å. The Hf(4)-O(2) bond length is 2.75 Å. The Hf(4)-O(4) bond length is 2.11 Å. In the fifth Hf site, Hf(5) is bonded to one N(1), one N(3), one N(4), one N(7), one O(2), and one O(4) atom to form distorted HfN4O2 octahedra that share corners with three equivalent Hf(1)N4O2 octahedra,  a cornercorner with one Hf(2)N3O tetrahedra, edges with three equivalent Hf(8)N4O2 octahedra, and  a faceface with one Hf(7)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 38-52°. The Hf(5)-N(1) bond length is 2.43 Å. The Hf(5)-N(3) bond length is 2.18 Å. The Hf(5)-N(4) bond length is 2.42 Å. The Hf(5)-N(7) bond length is 2.07 Å. The Hf(5)-O(2) bond length is 2.36 Å. The Hf(5)-O(4) bond length is 2.06 Å. In the sixth Hf site, Hf(6) is bonded in a 6-coordinate geometry to one N(1), one N(2), one N(4), one N(6), one O(1), and one O(2) atom. The Hf(6)-N(1) bond length is 2.25 Å. The Hf(6)-N(2) bond length is 2.09 Å. The Hf(6)-N(4) bond length is 2.32 Å. The Hf(6)-N(6) bond length is 2.12 Å. The Hf(6)-O(1) bond length is 2.13 Å. The Hf(6)-O(2) bond length is 2.70 Å. In the seventh Hf site, Hf(7) is bonded to one N(1), one N(2), one N(4), one N(6), one O(1), and one O(2) atom to form distorted HfN4O2 octahedra that share corners with three equivalent Hf(8)N4O2 octahedra,  a cornercorner with one Ca(1)N3O tetrahedra,  a cornercorner with one Hf(3)N3O tetrahedra, edges with three equivalent Hf(1)N4O2 octahedra, and  a faceface with one Hf(5)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 41-50°. The Hf(7)-N(1) bond length is 2.49 Å. The Hf(7)-N(2) bond length is 2.18 Å. The Hf(7)-N(4) bond length is 2.36 Å. The Hf(7)-N(6) bond length is 2.06 Å. The Hf(7)-O(1) bond length is 2.10 Å. The Hf(7)-O(2) bond length is 2.40 Å. In the eighth Hf site, Hf(8) is bonded to one N(1), one N(3), one N(4), one N(7), one O(2), and one O(4) atom to form distorted HfN4O2 octahedra that share corners with three equivalent Hf(7)N4O2 octahedra,  a cornercorner with one Hf(2)N3O tetrahedra, edges with three equivalent Hf(5)N4O2 octahedra, and  a faceface with one Hf(1)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 41-50°. The Hf(8)-N(1) bond length is 2.41 Å. The Hf(8)-N(3) bond length is 2.18 Å. The Hf(8)-N(4) bond length is 2.50 Å. The Hf(8)-N(7) bond length is 2.02 Å. The Hf(8)-O(2) bond length is 2.40 Å. The Hf(8)-O(4) bond length is 2.10 Å. There are eight inequivalent N sites. In the first N site, N(1) is bonded to one Hf(1), one Hf(4), one Hf(5), one Hf(6), one Hf(7), and one Hf(8) atom to form distorted NHf6 pentagonal pyramids that share  a cornercorner with one N(6)CaHf3 tetrahedra,  a cornercorner with one N(2)Hf4 tetrahedra,  a cornercorner with one N(3)Hf4 tetrahedra, edges with three equivalent N(4)Hf6 pentagonal pyramids,  an edgeedge with one N(6)CaHf3 tetrahedra,  an edgeedge with one N(2)Hf4 tetrahedra, and  an edgeedge with one N(3)Hf4 tetrahedra. In the second N site, N(2) is bonded to one Hf(1), one Hf(3), one Hf(6), and one Hf(7) atom to form NHf4 tetrahedra that share  a cornercorner with one N(1)Hf6 pentagonal pyramid,  a cornercorner with one N(4)Hf6 pentagonal pyramid, corners with three equivalent N(6)CaHf3 tetrahedra,  an edgeedge with one N(1)Hf6 pentagonal pyramid, and  an edgeedge with one N(4)Hf6 pentagonal pyramid. In the third N site, N(3) is bonded to one Hf(2), one Hf(4), one Hf(5), and one Hf(8) atom to form a mixture of corner and edge-sharing NHf4 tetrahedra. In the fourth N site, N(4) is bonded to one Hf(1), one Hf(4), one Hf(5), one Hf(6), one Hf(7), and one Hf(8) atom to form distorted NHf6 pentagonal pyramids that share  a cornercorner with one N(6)CaHf3 tetrahedra,  a cornercorner with one N(2)Hf4 tetrahedra,  a cornercorner with one N(3)Hf4 tetrahedra, edges with three equivalent N(1)Hf6 pentagonal pyramids,  an edgeedge with one N(6)CaHf3 tetrahedra,  an edgeedge with one N(2)Hf4 tetrahedra, and  an edgeedge with one N(3)Hf4 tetrahedra. In the fifth N site, N(5) is bonded in a trigonal planar geometry to one Ca(1), one Hf(2), and one Hf(3) atom. In the sixth N site, N(6) is bonded to one Ca(1), one Hf(1), one Hf(6), and one Hf(7) atom to form NCaHf3 tetrahedra that share  a cornercorner with one N(1)Hf6 pentagonal pyramid,  a cornercorner with one N(4)Hf6 pentagonal pyramid, corners with three equivalent N(2)Hf4 tetrahedra,  an edgeedge with one N(1)Hf6 pentagonal pyramid, and  an edgeedge with one N(4)Hf6 pentagonal pyramid. In the seventh N site, N(7) is bonded in a trigonal non-coplanar geometry to one Hf(4), one Hf(5), and one Hf(8) atom. In the eighth N site, N(8) is bonded in a distorted trigonal planar geometry to one Ca(1), one Hf(2), and one Hf(3) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Hf(1), one Hf(6), and one Hf(7) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Hf(1), one Hf(4), one Hf(5), one Hf(6), one Hf(7), and one Hf(8) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ca(1), one Hf(2), and one Hf(3) atom. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Hf(4), one Hf(5), and one Hf(8) atom.