CaHf8(N2O)4 crystallizes in the triclinic P1 space group. Ca(1) is bonded to one N(1), one N(2), one N(4), and one O(2) atom to form CaN3O tetrahedra that share  a cornercorner with one Hf(3)N4O2 octahedra,  a cornercorner with one Hf(6)N4O2 octahedra,  a cornercorner with one Hf(7)N4O2 octahedra, corners with three equivalent Hf(1)N3O tetrahedra, and corners with three equivalent Hf(5)N3O tetrahedra. The corner-sharing octahedral tilt angles are 65°. There are eight inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to one N(1), one N(4), one N(6), and one O(2) atom to form HfN3O tetrahedra that share  a cornercorner with one Hf(3)N4O2 octahedra,  a cornercorner with one Hf(6)N4O2 octahedra,  a cornercorner with one Hf(7)N4O2 octahedra, corners with three equivalent Ca(1)N3O tetrahedra, and corners with three equivalent Hf(5)N3O tetrahedra. The corner-sharing octahedral tilt angles range from 59-69°. In the second Hf site, Hf(2) is bonded in a 6-coordinate geometry to one N(3), one N(5), one N(7), one N(8), one O(3), and one O(4) atom. In the third Hf site, Hf(3) is bonded to one N(2), one N(5), one N(6), one N(8), one O(1), and one O(3) atom to form distorted HfN4O2 octahedra that share  a cornercorner with one Ca(1)N3O tetrahedra,  a cornercorner with one Hf(1)N3O tetrahedra, edges with three equivalent Hf(6)N4O2 octahedra, edges with three equivalent Hf(7)N4O2 octahedra, and  a faceface with one Hf(4)N4O2 octahedra. In the fourth Hf site, Hf(4) is bonded to one N(3), one N(5), one N(7), one N(8), one O(3), and one O(4) atom to form distorted HfN4O2 octahedra that share corners with three equivalent Hf(6)N4O2 octahedra, corners with three equivalent Hf(7)N4O2 octahedra,  a cornercorner with one Hf(5)N3O tetrahedra, and  a faceface with one Hf(3)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 40-53°. In the fifth Hf site, Hf(5) is bonded to one N(1), one N(4), one N(7), and one O(2) atom to form HfN3O tetrahedra that share  a cornercorner with one Hf(4)N4O2 octahedra, corners with three equivalent Ca(1)N3O tetrahedra, and corners with three equivalent Hf(1)N3O tetrahedra. The corner-sharing octahedral tilt angles are 61°. In the sixth Hf site, Hf(6) is bonded to one N(2), one N(5), one N(6), one N(8), one O(1), and one O(3) atom to form distorted HfN4O2 octahedra that share corners with three equivalent Hf(4)N4O2 octahedra,  a cornercorner with one Ca(1)N3O tetrahedra,  a cornercorner with one Hf(1)N3O tetrahedra, edges with three equivalent Hf(3)N4O2 octahedra, and edges with three equivalent Hf(7)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 43-53°. In the seventh Hf site, Hf(7) is bonded to one N(2), one N(5), one N(6), one N(8), one O(1), and one O(3) atom to form distorted HfN4O2 octahedra that share corners with three equivalent Hf(4)N4O2 octahedra,  a cornercorner with one Ca(1)N3O tetrahedra,  a cornercorner with one Hf(1)N3O tetrahedra, edges with three equivalent Hf(3)N4O2 octahedra, and edges with three equivalent Hf(6)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 40-51°. In the eighth Hf site, Hf(8) is bonded in a 6-coordinate geometry to one N(3), one N(5), one N(7), one N(8), one O(3), and one O(4) atom. There are eight inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one Ca(1), one Hf(1), and one Hf(5) atom. In the second N site, N(2) is bonded to one Ca(1), one Hf(3), one Hf(6), and one Hf(7) atom to form NCaHf3 tetrahedra that share  a cornercorner with one N(5)Hf6 pentagonal pyramid, corners with three equivalent N(6)Hf4 tetrahedra, and  an edgeedge with one N(5)Hf6 pentagonal pyramid. In the third N site, N(3) is bonded in a trigonal non-coplanar geometry to one Hf(2), one Hf(4), and one Hf(8) atom. In the fourth N site, N(4) is bonded in a trigonal planar geometry to one Ca(1), one Hf(1), and one Hf(5) atom. In the fifth N site, N(5) is bonded to one Hf(2), one Hf(3), one Hf(4), one Hf(6), one Hf(7), and one Hf(8) atom to form distorted NHf6 pentagonal pyramids that share  a cornercorner with one N(2)CaHf3 tetrahedra,  a cornercorner with one N(6)Hf4 tetrahedra,  a cornercorner with one N(7)Hf4 tetrahedra,  an edgeedge with one N(2)CaHf3 tetrahedra,  an edgeedge with one N(6)Hf4 tetrahedra, and  an edgeedge with one N(7)Hf4 tetrahedra. In the sixth N site, N(6) 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(5)Hf6 pentagonal pyramid, corners with three equivalent N(2)CaHf3 tetrahedra, and  an edgeedge with one N(5)Hf6 pentagonal pyramid. In the seventh N site, N(7) is bonded to one Hf(2), one Hf(4), one Hf(5), and one Hf(8) atom to form a mixture of edge and corner-sharing NHf4 tetrahedra. In the eighth N site, N(8) is bonded in a 6-coordinate geometry to one Hf(2), one Hf(3), one Hf(4), one Hf(6), one Hf(7), and one Hf(8) 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(3), one Hf(6), and one Hf(7) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Hf(1), and one Hf(5) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Hf(2), one Hf(3), one Hf(4), one Hf(6), one Hf(7), and one Hf(8) atom. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Hf(2), one Hf(4), and one Hf(8) atom.
CaHf8(N2O)4 crystallizes in the triclinic P1 space group. Ca(1) is bonded to one N(1), one N(2), one N(4), and one O(2) atom to form CaN3O tetrahedra that share  a cornercorner with one Hf(3)N4O2 octahedra,  a cornercorner with one Hf(6)N4O2 octahedra,  a cornercorner with one Hf(7)N4O2 octahedra, corners with three equivalent Hf(1)N3O tetrahedra, and corners with three equivalent Hf(5)N3O tetrahedra. The corner-sharing octahedral tilt angles are 65°. The Ca(1)-N(1) bond length is 2.24 Å. The Ca(1)-N(2) bond length is 2.43 Å. The Ca(1)-N(4) bond length is 2.24 Å. The Ca(1)-O(2) bond length is 2.25 Å. There are eight inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to one N(1), one N(4), one N(6), and one O(2) atom to form HfN3O tetrahedra that share  a cornercorner with one Hf(3)N4O2 octahedra,  a cornercorner with one Hf(6)N4O2 octahedra,  a cornercorner with one Hf(7)N4O2 octahedra, corners with three equivalent Ca(1)N3O tetrahedra, and corners with three equivalent Hf(5)N3O tetrahedra. The corner-sharing octahedral tilt angles range from 59-69°. The Hf(1)-N(1) bond length is 1.95 Å. The Hf(1)-N(4) bond length is 1.98 Å. The Hf(1)-N(6) bond length is 2.11 Å. The Hf(1)-O(2) bond length is 1.99 Å. In the second Hf site, Hf(2) is bonded in a 6-coordinate geometry to one N(3), one N(5), one N(7), one N(8), one O(3), and one O(4) atom. The Hf(2)-N(3) bond length is 2.01 Å. The Hf(2)-N(5) bond length is 2.45 Å. The Hf(2)-N(7) bond length is 2.15 Å. The Hf(2)-N(8) bond length is 2.28 Å. The Hf(2)-O(3) bond length is 2.92 Å. The Hf(2)-O(4) bond length is 2.11 Å. In the third Hf site, Hf(3) is bonded to one N(2), one N(5), one N(6), one N(8), one O(1), and one O(3) atom to form distorted HfN4O2 octahedra that share  a cornercorner with one Ca(1)N3O tetrahedra,  a cornercorner with one Hf(1)N3O tetrahedra, edges with three equivalent Hf(6)N4O2 octahedra, edges with three equivalent Hf(7)N4O2 octahedra, and  a faceface with one Hf(4)N4O2 octahedra. The Hf(3)-N(2) bond length is 2.06 Å. The Hf(3)-N(5) bond length is 2.26 Å. The Hf(3)-N(6) bond length is 2.15 Å. The Hf(3)-N(8) bond length is 2.45 Å. The Hf(3)-O(1) bond length is 2.12 Å. The Hf(3)-O(3) bond length is 2.53 Å. In the fourth Hf site, Hf(4) is bonded to one N(3), one N(5), one N(7), one N(8), one O(3), and one O(4) atom to form distorted HfN4O2 octahedra that share corners with three equivalent Hf(6)N4O2 octahedra, corners with three equivalent Hf(7)N4O2 octahedra,  a cornercorner with one Hf(5)N3O tetrahedra, and  a faceface with one Hf(3)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 40-53°. The Hf(4)-N(3) bond length is 2.09 Å. The Hf(4)-N(5) bond length is 2.26 Å. The Hf(4)-N(7) bond length is 2.11 Å. The Hf(4)-N(8) bond length is 2.37 Å. The Hf(4)-O(3) bond length is 2.44 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(4), one N(7), and one O(2) atom to form HfN3O tetrahedra that share  a cornercorner with one Hf(4)N4O2 octahedra, corners with three equivalent Ca(1)N3O tetrahedra, and corners with three equivalent Hf(1)N3O tetrahedra. The corner-sharing octahedral tilt angles are 61°. The Hf(5)-N(1) bond length is 2.00 Å. The Hf(5)-N(4) bond length is 1.95 Å. The Hf(5)-N(7) bond length is 2.12 Å. The Hf(5)-O(2) bond length is 1.98 Å. In the sixth Hf site, Hf(6) is bonded to one N(2), one N(5), one N(6), one N(8), one O(1), and one O(3) atom to form distorted HfN4O2 octahedra that share corners with three equivalent Hf(4)N4O2 octahedra,  a cornercorner with one Ca(1)N3O tetrahedra,  a cornercorner with one Hf(1)N3O tetrahedra, edges with three equivalent Hf(3)N4O2 octahedra, and edges with three equivalent Hf(7)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 43-53°. The Hf(6)-N(2) bond length is 2.10 Å. The Hf(6)-N(5) bond length is 2.38 Å. The Hf(6)-N(6) bond length is 2.11 Å. The Hf(6)-N(8) bond length is 2.24 Å. The Hf(6)-O(1) bond length is 2.13 Å. The Hf(6)-O(3) bond length is 2.59 Å. In the seventh Hf site, Hf(7) is bonded to one N(2), one N(5), one N(6), one N(8), one O(1), and one O(3) atom to form distorted HfN4O2 octahedra that share corners with three equivalent Hf(4)N4O2 octahedra,  a cornercorner with one Ca(1)N3O tetrahedra,  a cornercorner with one Hf(1)N3O tetrahedra, edges with three equivalent Hf(3)N4O2 octahedra, and edges with three equivalent Hf(6)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 40-51°. The Hf(7)-N(2) bond length is 2.12 Å. The Hf(7)-N(5) bond length is 2.56 Å. The Hf(7)-N(6) bond length is 2.18 Å. The Hf(7)-N(8) bond length is 2.53 Å. The Hf(7)-O(1) bond length is 2.04 Å. The Hf(7)-O(3) bond length is 2.24 Å. In the eighth Hf site, Hf(8) is bonded in a 6-coordinate geometry to one N(3), one N(5), one N(7), one N(8), one O(3), and one O(4) atom. The Hf(8)-N(3) bond length is 2.10 Å. The Hf(8)-N(5) bond length is 2.50 Å. The Hf(8)-N(7) bond length is 2.16 Å. The Hf(8)-N(8) bond length is 2.55 Å. The Hf(8)-O(3) bond length is 2.31 Å. The Hf(8)-O(4) bond length is 2.04 Å. There are eight inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one Ca(1), one Hf(1), and one Hf(5) atom. In the second N site, N(2) is bonded to one Ca(1), one Hf(3), one Hf(6), and one Hf(7) atom to form NCaHf3 tetrahedra that share  a cornercorner with one N(5)Hf6 pentagonal pyramid, corners with three equivalent N(6)Hf4 tetrahedra, and  an edgeedge with one N(5)Hf6 pentagonal pyramid. In the third N site, N(3) is bonded in a trigonal non-coplanar geometry to one Hf(2), one Hf(4), and one Hf(8) atom. In the fourth N site, N(4) is bonded in a trigonal planar geometry to one Ca(1), one Hf(1), and one Hf(5) atom. In the fifth N site, N(5) is bonded to one Hf(2), one Hf(3), one Hf(4), one Hf(6), one Hf(7), and one Hf(8) atom to form distorted NHf6 pentagonal pyramids that share  a cornercorner with one N(2)CaHf3 tetrahedra,  a cornercorner with one N(6)Hf4 tetrahedra,  a cornercorner with one N(7)Hf4 tetrahedra,  an edgeedge with one N(2)CaHf3 tetrahedra,  an edgeedge with one N(6)Hf4 tetrahedra, and  an edgeedge with one N(7)Hf4 tetrahedra. In the sixth N site, N(6) 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(5)Hf6 pentagonal pyramid, corners with three equivalent N(2)CaHf3 tetrahedra, and  an edgeedge with one N(5)Hf6 pentagonal pyramid. In the seventh N site, N(7) is bonded to one Hf(2), one Hf(4), one Hf(5), and one Hf(8) atom to form a mixture of edge and corner-sharing NHf4 tetrahedra. In the eighth N site, N(8) is bonded in a 6-coordinate geometry to one Hf(2), one Hf(3), one Hf(4), one Hf(6), one Hf(7), and one Hf(8) 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(3), one Hf(6), and one Hf(7) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Hf(1), and one Hf(5) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Hf(2), one Hf(3), one Hf(4), one Hf(6), one Hf(7), and one Hf(8) atom. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Hf(2), one Hf(4), and one Hf(8) atom.