Hf2ON2 crystallizes in the triclinic P1 space group. There are eight inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 7-coordinate geometry to one N(1), one N(2), one N(3), one N(4), one N(5), one N(7), and one O(3) atom. In the second Hf site, Hf(2) is bonded in a 7-coordinate geometry to one N(1), one N(2), one N(3), one N(4), one N(8), one O(1), and one O(4) atom. In the third Hf site, Hf(3) is bonded in a 7-coordinate geometry to one N(1), one N(2), one N(3), one N(4), one N(6), one O(1), and one O(4) atom. In the fourth Hf site, Hf(4) is bonded in a 7-coordinate geometry to one N(1), one N(2), one N(3), one N(4), one N(5), one O(2), and one O(3) atom. In the fifth Hf site, Hf(5) is bonded to one N(3), one N(5), one N(6), one N(8), one O(1), and one O(2) atom to form a mixture of distorted edge and corner-sharing HfN4O2 octahedra. The corner-sharing octahedral tilt angles range from 60-64°. In the sixth Hf site, Hf(6) is bonded to one N(4), one N(5), one N(6), one N(7), one O(1), and one O(2) atom to form a mixture of edge and corner-sharing HfN4O2 octahedra. The corner-sharing octahedral tilt angles range from 60-62°. In the seventh Hf site, Hf(7) is bonded in a 7-coordinate geometry to one N(1), one N(5), one N(7), one N(8), one O(2), one O(3), and one O(4) atom. In the eighth Hf site, Hf(8) is bonded to one N(2), one N(6), one N(7), one N(8), one O(3), and one O(4) atom to form distorted corner-sharing HfN4O2 octahedra. The corner-sharing octahedral tilt angles range from 60-64°. There are eight inequivalent N sites. In the first N site, N(1) is bonded to one Hf(1), one Hf(2), one Hf(3), one Hf(4), and one Hf(7) atom to form distorted NHf5 trigonal bipyramids that share corners with four equivalent N(4)Hf5 square pyramids,  a cornercorner with one N(6)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra,  a cornercorner with one N(5)Hf5 trigonal bipyramid,  a cornercorner with one O(3)Hf4 trigonal pyramid, edges with two equivalent N(2)Hf5 square pyramids,  an edgeedge with one N(7)Hf4 tetrahedra,  an edgeedge with one N(8)Hf4 tetrahedra,  an edgeedge with one N(5)Hf5 trigonal bipyramid, edges with two equivalent N(3)Hf5 trigonal bipyramids,  an edgeedge with one O(1)Hf4 trigonal pyramid, and  an edgeedge with one O(3)Hf4 trigonal pyramid. In the second N site, N(2) is bonded to one Hf(1), one Hf(2), one Hf(3), one Hf(4), and one Hf(8) atom to form NHf5 square pyramids that share  a cornercorner with one O(2)Hf4 tetrahedra, corners with two equivalent N(6)Hf4 tetrahedra, corners with four equivalent N(3)Hf5 trigonal bipyramids,  a cornercorner with one O(3)Hf4 trigonal pyramid, edges with two equivalent N(4)Hf5 square pyramids,  an edgeedge with one N(7)Hf4 tetrahedra,  an edgeedge with one N(8)Hf4 tetrahedra,  an edgeedge with one N(5)Hf5 trigonal bipyramid, edges with two equivalent N(1)Hf5 trigonal bipyramids,  an edgeedge with one O(1)Hf4 trigonal pyramid, and  an edgeedge with one O(3)Hf4 trigonal pyramid. In the third N site, N(3) is bonded to one Hf(1), one Hf(2), one Hf(3), one Hf(4), and one Hf(5) atom to form distorted NHf5 trigonal bipyramids that share corners with four equivalent N(2)Hf5 square pyramids,  a cornercorner with one N(7)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra,  a cornercorner with one N(5)Hf5 trigonal bipyramid,  a cornercorner with one O(1)Hf4 trigonal pyramid, edges with two equivalent N(4)Hf5 square pyramids,  an edgeedge with one N(6)Hf4 tetrahedra,  an edgeedge with one O(2)Hf4 tetrahedra,  an edgeedge with one N(5)Hf5 trigonal bipyramid, edges with two equivalent N(1)Hf5 trigonal bipyramids,  an edgeedge with one O(1)Hf4 trigonal pyramid, and  an edgeedge with one O(3)Hf4 trigonal pyramid. In the fourth N site, N(4) is bonded to one Hf(1), one Hf(2), one Hf(3), one Hf(4), and one Hf(6) atom to form NHf5 square pyramids that share  a cornercorner with one N(8)Hf4 tetrahedra, corners with two equivalent N(7)Hf4 tetrahedra,  a cornercorner with one N(5)Hf5 trigonal bipyramid, corners with four equivalent N(1)Hf5 trigonal bipyramids,  a cornercorner with one O(1)Hf4 trigonal pyramid, edges with two equivalent N(2)Hf5 square pyramids,  an edgeedge with one N(6)Hf4 tetrahedra,  an edgeedge with one O(2)Hf4 tetrahedra,  an edgeedge with one N(5)Hf5 trigonal bipyramid, edges with two equivalent N(3)Hf5 trigonal bipyramids,  an edgeedge with one O(1)Hf4 trigonal pyramid, and  an edgeedge with one O(3)Hf4 trigonal pyramid. In the fifth N site, N(5) is bonded to one Hf(1), one Hf(4), one Hf(5), one Hf(6), and one Hf(7) atom to form distorted NHf5 trigonal bipyramids that share  a cornercorner with one N(4)Hf5 square pyramid,  a cornercorner with one N(7)Hf4 tetrahedra, corners with two equivalent N(6)Hf4 tetrahedra,  a cornercorner with one N(1)Hf5 trigonal bipyramid,  a cornercorner with one N(3)Hf5 trigonal bipyramid, corners with two equivalent O(1)Hf4 trigonal pyramids, corners with three equivalent O(3)Hf4 trigonal pyramids,  an edgeedge with one N(2)Hf5 square pyramid,  an edgeedge with one N(4)Hf5 square pyramid,  an edgeedge with one N(7)Hf4 tetrahedra,  an edgeedge with one N(8)Hf4 tetrahedra, edges with two equivalent O(2)Hf4 tetrahedra,  an edgeedge with one N(1)Hf5 trigonal bipyramid, and  an edgeedge with one N(3)Hf5 trigonal bipyramid. In the sixth N site, N(6) is bonded to one Hf(3), one Hf(5), one Hf(6), and one Hf(8) atom to form distorted NHf4 tetrahedra that share corners with two equivalent N(2)Hf5 square pyramids, corners with two equivalent N(7)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra,  a cornercorner with one N(1)Hf5 trigonal bipyramid, corners with two equivalent N(5)Hf5 trigonal bipyramids,  a cornercorner with one O(1)Hf4 trigonal pyramid,  a cornercorner with one O(3)Hf4 trigonal pyramid,  an edgeedge with one N(4)Hf5 square pyramid,  an edgeedge with one N(3)Hf5 trigonal bipyramid, and  an edgeedge with one O(1)Hf4 trigonal pyramid. In the seventh N site, N(7) is bonded to one Hf(1), one Hf(6), one Hf(7), and one Hf(8) atom to form NHf4 tetrahedra that share corners with two equivalent N(4)Hf5 square pyramids, corners with two equivalent N(6)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra,  a cornercorner with one N(3)Hf5 trigonal bipyramid,  a cornercorner with one N(5)Hf5 trigonal bipyramid,  a cornercorner with one O(1)Hf4 trigonal pyramid,  a cornercorner with one O(3)Hf4 trigonal pyramid,  an edgeedge with one N(2)Hf5 square pyramid,  an edgeedge with one N(1)Hf5 trigonal bipyramid,  an edgeedge with one N(5)Hf5 trigonal bipyramid, and  an edgeedge with one O(3)Hf4 trigonal pyramid. In the eighth N site, N(8) is bonded to one Hf(2), one Hf(5), one Hf(7), and one Hf(8) atom to form NHf4 tetrahedra that share  a cornercorner with one N(4)Hf5 square pyramid, corners with two equivalent N(6)Hf4 tetrahedra, corners with two equivalent N(7)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra, corners with two equivalent N(3)Hf5 trigonal bipyramids, corners with two equivalent O(1)Hf4 trigonal pyramids, corners with two equivalent O(3)Hf4 trigonal pyramids,  an edgeedge with one N(2)Hf5 square pyramid,  an edgeedge with one N(1)Hf5 trigonal bipyramid, and  an edgeedge with one N(5)Hf5 trigonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Hf(2), one Hf(3), one Hf(5), and one Hf(6) atom to form distorted OHf4 trigonal pyramids that share  a cornercorner with one N(4)Hf5 square pyramid,  a cornercorner with one N(6)Hf4 tetrahedra,  a cornercorner with one N(7)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra,  a cornercorner with one N(3)Hf5 trigonal bipyramid, corners with two equivalent N(5)Hf5 trigonal bipyramids,  an edgeedge with one N(2)Hf5 square pyramid,  an edgeedge with one N(4)Hf5 square pyramid,  an edgeedge with one N(6)Hf4 tetrahedra,  an edgeedge with one N(1)Hf5 trigonal bipyramid, and  an edgeedge with one N(3)Hf5 trigonal bipyramid. In the second O site, O(2) is bonded to one Hf(4), one Hf(5), one Hf(6), and one Hf(7) atom to form OHf4 tetrahedra that share  a cornercorner with one N(2)Hf5 square pyramid, corners with two equivalent N(6)Hf4 tetrahedra, corners with two equivalent N(7)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent N(1)Hf5 trigonal bipyramids, corners with two equivalent O(1)Hf4 trigonal pyramids, corners with two equivalent O(3)Hf4 trigonal pyramids,  an edgeedge with one N(4)Hf5 square pyramid,  an edgeedge with one N(3)Hf5 trigonal bipyramid, and edges with two equivalent N(5)Hf5 trigonal bipyramids. In the third O site, O(3) is bonded to one Hf(1), one Hf(4), one Hf(7), and one Hf(8) atom to form distorted OHf4 trigonal pyramids that share  a cornercorner with one N(2)Hf5 square pyramid,  a cornercorner with one N(6)Hf4 tetrahedra,  a cornercorner with one N(7)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra,  a cornercorner with one N(1)Hf5 trigonal bipyramid, corners with three equivalent N(5)Hf5 trigonal bipyramids,  an edgeedge with one N(2)Hf5 square pyramid,  an edgeedge with one N(4)Hf5 square pyramid,  an edgeedge with one N(7)Hf4 tetrahedra,  an edgeedge with one N(1)Hf5 trigonal bipyramid, and  an edgeedge with one N(3)Hf5 trigonal bipyramid. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Hf(2), one Hf(3), one Hf(7), and one Hf(8) atom.
Hf2ON2 crystallizes in the triclinic P1 space group. There are eight inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 7-coordinate geometry to one N(1), one N(2), one N(3), one N(4), one N(5), one N(7), and one O(3) atom. The Hf(1)-N(1) bond length is 2.22 Å. The Hf(1)-N(2) bond length is 2.27 Å. The Hf(1)-N(3) bond length is 2.27 Å. The Hf(1)-N(4) bond length is 2.24 Å. The Hf(1)-N(5) bond length is 2.71 Å. The Hf(1)-N(7) bond length is 2.14 Å. The Hf(1)-O(3) bond length is 2.14 Å. In the second Hf site, Hf(2) is bonded in a 7-coordinate geometry to one N(1), one N(2), one N(3), one N(4), one N(8), one O(1), and one O(4) atom. The Hf(2)-N(1) bond length is 2.20 Å. The Hf(2)-N(2) bond length is 2.23 Å. The Hf(2)-N(3) bond length is 2.30 Å. The Hf(2)-N(4) bond length is 2.27 Å. The Hf(2)-N(8) bond length is 2.13 Å. The Hf(2)-O(1) bond length is 2.44 Å. The Hf(2)-O(4) bond length is 2.16 Å. In the third Hf site, Hf(3) is bonded in a 7-coordinate geometry to one N(1), one N(2), one N(3), one N(4), one N(6), one O(1), and one O(4) atom. The Hf(3)-N(1) bond length is 2.35 Å. The Hf(3)-N(2) bond length is 2.27 Å. The Hf(3)-N(3) bond length is 2.19 Å. The Hf(3)-N(4) bond length is 2.21 Å. The Hf(3)-N(6) bond length is 2.13 Å. The Hf(3)-O(1) bond length is 2.17 Å. The Hf(3)-O(4) bond length is 2.56 Å. In the fourth Hf site, Hf(4) is bonded in a 7-coordinate geometry to one N(1), one N(2), one N(3), one N(4), one N(5), one O(2), and one O(3) atom. The Hf(4)-N(1) bond length is 2.25 Å. The Hf(4)-N(2) bond length is 2.21 Å. The Hf(4)-N(3) bond length is 2.24 Å. The Hf(4)-N(4) bond length is 2.27 Å. The Hf(4)-N(5) bond length is 2.10 Å. The Hf(4)-O(2) bond length is 2.27 Å. The Hf(4)-O(3) bond length is 2.45 Å. In the fifth Hf site, Hf(5) is bonded to one N(3), one N(5), one N(6), one N(8), one O(1), and one O(2) atom to form a mixture of distorted edge and corner-sharing HfN4O2 octahedra. The corner-sharing octahedral tilt angles range from 60-64°. The Hf(5)-N(3) bond length is 2.20 Å. The Hf(5)-N(5) bond length is 2.18 Å. The Hf(5)-N(6) bond length is 2.19 Å. The Hf(5)-N(8) bond length is 2.12 Å. The Hf(5)-O(1) bond length is 2.15 Å. The Hf(5)-O(2) bond length is 2.14 Å. In the sixth Hf site, Hf(6) is bonded to one N(4), one N(5), one N(6), one N(7), one O(1), and one O(2) atom to form a mixture of edge and corner-sharing HfN4O2 octahedra. The corner-sharing octahedral tilt angles range from 60-62°. The Hf(6)-N(4) bond length is 2.20 Å. The Hf(6)-N(5) bond length is 2.14 Å. The Hf(6)-N(6) bond length is 2.22 Å. The Hf(6)-N(7) bond length is 2.12 Å. The Hf(6)-O(1) bond length is 2.12 Å. The Hf(6)-O(2) bond length is 2.17 Å. In the seventh Hf site, Hf(7) is bonded in a 7-coordinate geometry to one N(1), one N(5), one N(7), one N(8), one O(2), one O(3), and one O(4) atom. The Hf(7)-N(1) bond length is 2.21 Å. The Hf(7)-N(5) bond length is 2.61 Å. The Hf(7)-N(7) bond length is 2.12 Å. The Hf(7)-N(8) bond length is 2.10 Å. The Hf(7)-O(2) bond length is 2.18 Å. The Hf(7)-O(3) bond length is 2.25 Å. The Hf(7)-O(4) bond length is 2.27 Å. In the eighth Hf site, Hf(8) is bonded to one N(2), one N(6), one N(7), one N(8), one O(3), and one O(4) atom to form distorted corner-sharing HfN4O2 octahedra. The corner-sharing octahedral tilt angles range from 60-64°. The Hf(8)-N(2) bond length is 2.18 Å. The Hf(8)-N(6) bond length is 2.16 Å. The Hf(8)-N(7) bond length is 2.16 Å. The Hf(8)-N(8) bond length is 2.14 Å. The Hf(8)-O(3) bond length is 2.15 Å. The Hf(8)-O(4) bond length is 2.17 Å. There are eight inequivalent N sites. In the first N site, N(1) is bonded to one Hf(1), one Hf(2), one Hf(3), one Hf(4), and one Hf(7) atom to form distorted NHf5 trigonal bipyramids that share corners with four equivalent N(4)Hf5 square pyramids,  a cornercorner with one N(6)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra,  a cornercorner with one N(5)Hf5 trigonal bipyramid,  a cornercorner with one O(3)Hf4 trigonal pyramid, edges with two equivalent N(2)Hf5 square pyramids,  an edgeedge with one N(7)Hf4 tetrahedra,  an edgeedge with one N(8)Hf4 tetrahedra,  an edgeedge with one N(5)Hf5 trigonal bipyramid, edges with two equivalent N(3)Hf5 trigonal bipyramids,  an edgeedge with one O(1)Hf4 trigonal pyramid, and  an edgeedge with one O(3)Hf4 trigonal pyramid. In the second N site, N(2) is bonded to one Hf(1), one Hf(2), one Hf(3), one Hf(4), and one Hf(8) atom to form NHf5 square pyramids that share  a cornercorner with one O(2)Hf4 tetrahedra, corners with two equivalent N(6)Hf4 tetrahedra, corners with four equivalent N(3)Hf5 trigonal bipyramids,  a cornercorner with one O(3)Hf4 trigonal pyramid, edges with two equivalent N(4)Hf5 square pyramids,  an edgeedge with one N(7)Hf4 tetrahedra,  an edgeedge with one N(8)Hf4 tetrahedra,  an edgeedge with one N(5)Hf5 trigonal bipyramid, edges with two equivalent N(1)Hf5 trigonal bipyramids,  an edgeedge with one O(1)Hf4 trigonal pyramid, and  an edgeedge with one O(3)Hf4 trigonal pyramid. In the third N site, N(3) is bonded to one Hf(1), one Hf(2), one Hf(3), one Hf(4), and one Hf(5) atom to form distorted NHf5 trigonal bipyramids that share corners with four equivalent N(2)Hf5 square pyramids,  a cornercorner with one N(7)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra,  a cornercorner with one N(5)Hf5 trigonal bipyramid,  a cornercorner with one O(1)Hf4 trigonal pyramid, edges with two equivalent N(4)Hf5 square pyramids,  an edgeedge with one N(6)Hf4 tetrahedra,  an edgeedge with one O(2)Hf4 tetrahedra,  an edgeedge with one N(5)Hf5 trigonal bipyramid, edges with two equivalent N(1)Hf5 trigonal bipyramids,  an edgeedge with one O(1)Hf4 trigonal pyramid, and  an edgeedge with one O(3)Hf4 trigonal pyramid. In the fourth N site, N(4) is bonded to one Hf(1), one Hf(2), one Hf(3), one Hf(4), and one Hf(6) atom to form NHf5 square pyramids that share  a cornercorner with one N(8)Hf4 tetrahedra, corners with two equivalent N(7)Hf4 tetrahedra,  a cornercorner with one N(5)Hf5 trigonal bipyramid, corners with four equivalent N(1)Hf5 trigonal bipyramids,  a cornercorner with one O(1)Hf4 trigonal pyramid, edges with two equivalent N(2)Hf5 square pyramids,  an edgeedge with one N(6)Hf4 tetrahedra,  an edgeedge with one O(2)Hf4 tetrahedra,  an edgeedge with one N(5)Hf5 trigonal bipyramid, edges with two equivalent N(3)Hf5 trigonal bipyramids,  an edgeedge with one O(1)Hf4 trigonal pyramid, and  an edgeedge with one O(3)Hf4 trigonal pyramid. In the fifth N site, N(5) is bonded to one Hf(1), one Hf(4), one Hf(5), one Hf(6), and one Hf(7) atom to form distorted NHf5 trigonal bipyramids that share  a cornercorner with one N(4)Hf5 square pyramid,  a cornercorner with one N(7)Hf4 tetrahedra, corners with two equivalent N(6)Hf4 tetrahedra,  a cornercorner with one N(1)Hf5 trigonal bipyramid,  a cornercorner with one N(3)Hf5 trigonal bipyramid, corners with two equivalent O(1)Hf4 trigonal pyramids, corners with three equivalent O(3)Hf4 trigonal pyramids,  an edgeedge with one N(2)Hf5 square pyramid,  an edgeedge with one N(4)Hf5 square pyramid,  an edgeedge with one N(7)Hf4 tetrahedra,  an edgeedge with one N(8)Hf4 tetrahedra, edges with two equivalent O(2)Hf4 tetrahedra,  an edgeedge with one N(1)Hf5 trigonal bipyramid, and  an edgeedge with one N(3)Hf5 trigonal bipyramid. In the sixth N site, N(6) is bonded to one Hf(3), one Hf(5), one Hf(6), and one Hf(8) atom to form distorted NHf4 tetrahedra that share corners with two equivalent N(2)Hf5 square pyramids, corners with two equivalent N(7)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra,  a cornercorner with one N(1)Hf5 trigonal bipyramid, corners with two equivalent N(5)Hf5 trigonal bipyramids,  a cornercorner with one O(1)Hf4 trigonal pyramid,  a cornercorner with one O(3)Hf4 trigonal pyramid,  an edgeedge with one N(4)Hf5 square pyramid,  an edgeedge with one N(3)Hf5 trigonal bipyramid, and  an edgeedge with one O(1)Hf4 trigonal pyramid. In the seventh N site, N(7) is bonded to one Hf(1), one Hf(6), one Hf(7), and one Hf(8) atom to form NHf4 tetrahedra that share corners with two equivalent N(4)Hf5 square pyramids, corners with two equivalent N(6)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra,  a cornercorner with one N(3)Hf5 trigonal bipyramid,  a cornercorner with one N(5)Hf5 trigonal bipyramid,  a cornercorner with one O(1)Hf4 trigonal pyramid,  a cornercorner with one O(3)Hf4 trigonal pyramid,  an edgeedge with one N(2)Hf5 square pyramid,  an edgeedge with one N(1)Hf5 trigonal bipyramid,  an edgeedge with one N(5)Hf5 trigonal bipyramid, and  an edgeedge with one O(3)Hf4 trigonal pyramid. In the eighth N site, N(8) is bonded to one Hf(2), one Hf(5), one Hf(7), and one Hf(8) atom to form NHf4 tetrahedra that share  a cornercorner with one N(4)Hf5 square pyramid, corners with two equivalent N(6)Hf4 tetrahedra, corners with two equivalent N(7)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra, corners with two equivalent N(3)Hf5 trigonal bipyramids, corners with two equivalent O(1)Hf4 trigonal pyramids, corners with two equivalent O(3)Hf4 trigonal pyramids,  an edgeedge with one N(2)Hf5 square pyramid,  an edgeedge with one N(1)Hf5 trigonal bipyramid, and  an edgeedge with one N(5)Hf5 trigonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Hf(2), one Hf(3), one Hf(5), and one Hf(6) atom to form distorted OHf4 trigonal pyramids that share  a cornercorner with one N(4)Hf5 square pyramid,  a cornercorner with one N(6)Hf4 tetrahedra,  a cornercorner with one N(7)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra,  a cornercorner with one N(3)Hf5 trigonal bipyramid, corners with two equivalent N(5)Hf5 trigonal bipyramids,  an edgeedge with one N(2)Hf5 square pyramid,  an edgeedge with one N(4)Hf5 square pyramid,  an edgeedge with one N(6)Hf4 tetrahedra,  an edgeedge with one N(1)Hf5 trigonal bipyramid, and  an edgeedge with one N(3)Hf5 trigonal bipyramid. In the second O site, O(2) is bonded to one Hf(4), one Hf(5), one Hf(6), and one Hf(7) atom to form OHf4 tetrahedra that share  a cornercorner with one N(2)Hf5 square pyramid, corners with two equivalent N(6)Hf4 tetrahedra, corners with two equivalent N(7)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent N(1)Hf5 trigonal bipyramids, corners with two equivalent O(1)Hf4 trigonal pyramids, corners with two equivalent O(3)Hf4 trigonal pyramids,  an edgeedge with one N(4)Hf5 square pyramid,  an edgeedge with one N(3)Hf5 trigonal bipyramid, and edges with two equivalent N(5)Hf5 trigonal bipyramids. In the third O site, O(3) is bonded to one Hf(1), one Hf(4), one Hf(7), and one Hf(8) atom to form distorted OHf4 trigonal pyramids that share  a cornercorner with one N(2)Hf5 square pyramid,  a cornercorner with one N(6)Hf4 tetrahedra,  a cornercorner with one N(7)Hf4 tetrahedra, corners with two equivalent N(8)Hf4 tetrahedra, corners with two equivalent O(2)Hf4 tetrahedra,  a cornercorner with one N(1)Hf5 trigonal bipyramid, corners with three equivalent N(5)Hf5 trigonal bipyramids,  an edgeedge with one N(2)Hf5 square pyramid,  an edgeedge with one N(4)Hf5 square pyramid,  an edgeedge with one N(7)Hf4 tetrahedra,  an edgeedge with one N(1)Hf5 trigonal bipyramid, and  an edgeedge with one N(3)Hf5 trigonal bipyramid. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Hf(2), one Hf(3), one Hf(7), and one Hf(8) atom.