Gd2Zr2O7 crystallizes in the triclinic P1 space group. There are six inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 6-coordinate geometry to one O(15), one O(19), one O(21), one O(3), one O(8), and one O(9) atom. In the second Gd site, Gd(2) is bonded in a 6-coordinate geometry to one O(12), one O(15), one O(16), one O(21), one O(3), and one O(4) atom. In the third Gd site, Gd(3) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(17), one O(20), one O(6), and one O(7) atom. In the fourth Gd site, Gd(4) is bonded in a 7-coordinate geometry to one O(1), one O(13), one O(14), one O(17), one O(5), one O(6), and one O(7) atom. In the fifth Gd site, Gd(5) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(13), one O(17), one O(18), and one O(5) atom. In the sixth Gd site, Gd(6) is bonded in a 7-coordinate geometry to one O(1), one O(12), one O(14), one O(18), one O(20), one O(21), and one O(8) atom. There are six inequivalent Zr sites. In the first Zr site, Zr(1) is bonded to one O(11), one O(2), one O(4), and one O(7) atom to form corner-sharing ZrO4 tetrahedra. In the second Zr site, Zr(2) is bonded in a 5-coordinate geometry to one O(15), one O(16), one O(19), one O(2), and one O(3) atom. In the third Zr site, Zr(3) is bonded to one O(2), one O(3), one O(4), one O(5), and one O(9) atom to form distorted ZrO5 square pyramids that share corners with two equivalent Zr(1)O4 tetrahedra and  a cornercorner with one Zr(5)O5 trigonal bipyramid. In the fourth Zr site, Zr(4) is bonded to one O(12), one O(14), one O(16), one O(20), and one O(6) atom to form distorted ZrO5 square pyramids that share corners with two equivalent Zr(6)O6 octahedra and  a cornercorner with one Zr(5)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 37-61°. In the fifth Zr site, Zr(5) is bonded to one O(10), one O(13), one O(5), one O(6), and one O(7) atom to form distorted ZrO5 trigonal bipyramids that share  a cornercorner with one Zr(6)O6 octahedra,  a cornercorner with one Zr(3)O5 square pyramid,  a cornercorner with one Zr(4)O5 square pyramid, and  a cornercorner with one Zr(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. In the sixth Zr site, Zr(6) is bonded to one O(12), one O(13), one O(14), one O(15), one O(18), and one O(8) atom to form distorted corner-sharing ZrO6 octahedra. There are twenty-one inequivalent O sites. In the first O site, O(1) is bonded to one Gd(3), one Gd(4), one Gd(5), and one Gd(6) atom to form a mixture of edge and corner-sharing OGd4 tetrahedra. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Zr(1), one Zr(2), and one Zr(3) atom. In the third O site, O(3) is bonded in a trigonal pyramidal geometry to one Gd(1), one Gd(2), one Zr(2), and one Zr(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Gd(2), one Zr(1), and one Zr(3) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Gd(4), one Gd(5), one Zr(3), and one Zr(5) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Gd(3), one Gd(4), one Zr(4), and one Zr(5) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Gd(3), one Gd(4), one Zr(1), and one Zr(5) atom. In the eighth O site, O(8) is bonded in a trigonal non-coplanar geometry to one Gd(1), one Gd(6), and one Zr(6) atom. In the ninth O site, O(9) is bonded in a water-like geometry to one Gd(1) and one Zr(3) atom. In the tenth O site, O(10) is bonded in a trigonal non-coplanar geometry to one Gd(3), one Gd(5), and one Zr(5) atom. In the eleventh O site, O(11) is bonded in a single-bond geometry to one Zr(1) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Gd(2), one Gd(6), one Zr(4), and one Zr(6) atom. In the thirteenth O site, O(13) is bonded to one Gd(4), one Gd(5), one Zr(5), and one Zr(6) atom to form OGd2Zr2 trigonal pyramids that share corners with two equivalent O(1)Gd4 tetrahedra and  an edgeedge with one O(14)Gd2Zr2 tetrahedra. In the fourteenth O site, O(14) is bonded to one Gd(4), one Gd(6), one Zr(4), and one Zr(6) atom to form distorted OGd2Zr2 tetrahedra that share  an edgeedge with one O(1)Gd4 tetrahedra and  an edgeedge with one O(13)Gd2Zr2 trigonal pyramid. In the fifteenth O site, O(15) is bonded in a distorted rectangular see-saw-like geometry to one Gd(1), one Gd(2), one Zr(2), and one Zr(6) atom. In the sixteenth O site, O(16) is bonded in a distorted bent 150 degrees geometry to one Gd(2), one Zr(2), and one Zr(4) atom. In the seventeenth O site, O(17) is bonded in a trigonal non-coplanar geometry to one Gd(3), one Gd(4), and one Gd(5) atom. In the eighteenth O site, O(18) is bonded in a trigonal non-coplanar geometry to one Gd(5), one Gd(6), and one Zr(6) atom. In the nineteenth O site, O(19) is bonded in a water-like geometry to one Gd(1) and one Zr(2) atom. In the twentieth O site, O(20) is bonded in a trigonal non-coplanar geometry to one Gd(3), one Gd(6), and one Zr(4) atom. In the twenty-first O site, O(21) is bonded in a trigonal non-coplanar geometry to one Gd(1), one Gd(2), and one Gd(6) atom.
Gd2Zr2O7 crystallizes in the triclinic P1 space group. There are six inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 6-coordinate geometry to one O(15), one O(19), one O(21), one O(3), one O(8), and one O(9) atom. The Gd(1)-O(15) bond length is 2.61 Å. The Gd(1)-O(19) bond length is 2.27 Å. The Gd(1)-O(21) bond length is 2.25 Å. The Gd(1)-O(3) bond length is 2.41 Å. The Gd(1)-O(8) bond length is 2.24 Å. The Gd(1)-O(9) bond length is 2.33 Å. In the second Gd site, Gd(2) is bonded in a 6-coordinate geometry to one O(12), one O(15), one O(16), one O(21), one O(3), and one O(4) atom. The Gd(2)-O(12) bond length is 2.37 Å. The Gd(2)-O(15) bond length is 2.41 Å. The Gd(2)-O(16) bond length is 2.68 Å. The Gd(2)-O(21) bond length is 2.11 Å. The Gd(2)-O(3) bond length is 2.18 Å. The Gd(2)-O(4) bond length is 2.51 Å. In the third Gd site, Gd(3) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(17), one O(20), one O(6), and one O(7) atom. The Gd(3)-O(1) bond length is 2.30 Å. The Gd(3)-O(10) bond length is 2.28 Å. The Gd(3)-O(17) bond length is 2.22 Å. The Gd(3)-O(20) bond length is 2.25 Å. The Gd(3)-O(6) bond length is 2.79 Å. The Gd(3)-O(7) bond length is 2.31 Å. In the fourth Gd site, Gd(4) is bonded in a 7-coordinate geometry to one O(1), one O(13), one O(14), one O(17), one O(5), one O(6), and one O(7) atom. The Gd(4)-O(1) bond length is 2.19 Å. The Gd(4)-O(13) bond length is 2.56 Å. The Gd(4)-O(14) bond length is 2.30 Å. The Gd(4)-O(17) bond length is 2.22 Å. The Gd(4)-O(5) bond length is 2.77 Å. The Gd(4)-O(6) bond length is 2.38 Å. The Gd(4)-O(7) bond length is 3.04 Å. In the fifth Gd site, Gd(5) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(13), one O(17), one O(18), and one O(5) atom. The Gd(5)-O(1) bond length is 2.28 Å. The Gd(5)-O(10) bond length is 2.40 Å. The Gd(5)-O(13) bond length is 2.45 Å. The Gd(5)-O(17) bond length is 2.22 Å. The Gd(5)-O(18) bond length is 2.22 Å. The Gd(5)-O(5) bond length is 2.70 Å. In the sixth Gd site, Gd(6) is bonded in a 7-coordinate geometry to one O(1), one O(12), one O(14), one O(18), one O(20), one O(21), and one O(8) atom. The Gd(6)-O(1) bond length is 2.32 Å. The Gd(6)-O(12) bond length is 2.82 Å. The Gd(6)-O(14) bond length is 2.48 Å. The Gd(6)-O(18) bond length is 2.42 Å. The Gd(6)-O(20) bond length is 2.35 Å. The Gd(6)-O(21) bond length is 2.23 Å. The Gd(6)-O(8) bond length is 2.31 Å. There are six inequivalent Zr sites. In the first Zr site, Zr(1) is bonded to one O(11), one O(2), one O(4), and one O(7) atom to form corner-sharing ZrO4 tetrahedra. The Zr(1)-O(11) bond length is 1.84 Å. The Zr(1)-O(2) bond length is 2.09 Å. The Zr(1)-O(4) bond length is 2.03 Å. The Zr(1)-O(7) bond length is 2.09 Å. In the second Zr site, Zr(2) is bonded in a 5-coordinate geometry to one O(15), one O(16), one O(19), one O(2), and one O(3) atom. The Zr(2)-O(15) bond length is 2.16 Å. The Zr(2)-O(16) bond length is 2.10 Å. The Zr(2)-O(19) bond length is 1.90 Å. The Zr(2)-O(2) bond length is 2.23 Å. The Zr(2)-O(3) bond length is 2.06 Å. In the third Zr site, Zr(3) is bonded to one O(2), one O(3), one O(4), one O(5), and one O(9) atom to form distorted ZrO5 square pyramids that share corners with two equivalent Zr(1)O4 tetrahedra and  a cornercorner with one Zr(5)O5 trigonal bipyramid. The Zr(3)-O(2) bond length is 2.25 Å. The Zr(3)-O(3) bond length is 2.06 Å. The Zr(3)-O(4) bond length is 2.16 Å. The Zr(3)-O(5) bond length is 2.17 Å. The Zr(3)-O(9) bond length is 1.88 Å. In the fourth Zr site, Zr(4) is bonded to one O(12), one O(14), one O(16), one O(20), and one O(6) atom to form distorted ZrO5 square pyramids that share corners with two equivalent Zr(6)O6 octahedra and  a cornercorner with one Zr(5)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 37-61°. The Zr(4)-O(12) bond length is 2.04 Å. The Zr(4)-O(14) bond length is 2.10 Å. The Zr(4)-O(16) bond length is 2.01 Å. The Zr(4)-O(20) bond length is 1.95 Å. The Zr(4)-O(6) bond length is 2.19 Å. In the fifth Zr site, Zr(5) is bonded to one O(10), one O(13), one O(5), one O(6), and one O(7) atom to form distorted ZrO5 trigonal bipyramids that share  a cornercorner with one Zr(6)O6 octahedra,  a cornercorner with one Zr(3)O5 square pyramid,  a cornercorner with one Zr(4)O5 square pyramid, and  a cornercorner with one Zr(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. The Zr(5)-O(10) bond length is 1.95 Å. The Zr(5)-O(13) bond length is 2.11 Å. The Zr(5)-O(5) bond length is 2.23 Å. The Zr(5)-O(6) bond length is 2.05 Å. The Zr(5)-O(7) bond length is 2.16 Å. In the sixth Zr site, Zr(6) is bonded to one O(12), one O(13), one O(14), one O(15), one O(18), and one O(8) atom to form distorted corner-sharing ZrO6 octahedra. The Zr(6)-O(12) bond length is 2.09 Å. The Zr(6)-O(13) bond length is 2.22 Å. The Zr(6)-O(14) bond length is 2.22 Å. The Zr(6)-O(15) bond length is 2.38 Å. The Zr(6)-O(18) bond length is 2.12 Å. The Zr(6)-O(8) bond length is 2.00 Å. There are twenty-one inequivalent O sites. In the first O site, O(1) is bonded to one Gd(3), one Gd(4), one Gd(5), and one Gd(6) atom to form a mixture of edge and corner-sharing OGd4 tetrahedra. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Zr(1), one Zr(2), and one Zr(3) atom. In the third O site, O(3) is bonded in a trigonal pyramidal geometry to one Gd(1), one Gd(2), one Zr(2), and one Zr(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Gd(2), one Zr(1), and one Zr(3) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Gd(4), one Gd(5), one Zr(3), and one Zr(5) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Gd(3), one Gd(4), one Zr(4), and one Zr(5) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Gd(3), one Gd(4), one Zr(1), and one Zr(5) atom. In the eighth O site, O(8) is bonded in a trigonal non-coplanar geometry to one Gd(1), one Gd(6), and one Zr(6) atom. In the ninth O site, O(9) is bonded in a water-like geometry to one Gd(1) and one Zr(3) atom. In the tenth O site, O(10) is bonded in a trigonal non-coplanar geometry to one Gd(3), one Gd(5), and one Zr(5) atom. In the eleventh O site, O(11) is bonded in a single-bond geometry to one Zr(1) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Gd(2), one Gd(6), one Zr(4), and one Zr(6) atom. In the thirteenth O site, O(13) is bonded to one Gd(4), one Gd(5), one Zr(5), and one Zr(6) atom to form OGd2Zr2 trigonal pyramids that share corners with two equivalent O(1)Gd4 tetrahedra and  an edgeedge with one O(14)Gd2Zr2 tetrahedra. In the fourteenth O site, O(14) is bonded to one Gd(4), one Gd(6), one Zr(4), and one Zr(6) atom to form distorted OGd2Zr2 tetrahedra that share  an edgeedge with one O(1)Gd4 tetrahedra and  an edgeedge with one O(13)Gd2Zr2 trigonal pyramid. In the fifteenth O site, O(15) is bonded in a distorted rectangular see-saw-like geometry to one Gd(1), one Gd(2), one Zr(2), and one Zr(6) atom. In the sixteenth O site, O(16) is bonded in a distorted bent 150 degrees geometry to one Gd(2), one Zr(2), and one Zr(4) atom. In the seventeenth O site, O(17) is bonded in a trigonal non-coplanar geometry to one Gd(3), one Gd(4), and one Gd(5) atom. In the eighteenth O site, O(18) is bonded in a trigonal non-coplanar geometry to one Gd(5), one Gd(6), and one Zr(6) atom. In the nineteenth O site, O(19) is bonded in a water-like geometry to one Gd(1) and one Zr(2) atom. In the twentieth O site, O(20) is bonded in a trigonal non-coplanar geometry to one Gd(3), one Gd(6), and one Zr(4) atom. In the twenty-first O site, O(21) is bonded in a trigonal non-coplanar geometry to one Gd(1), one Gd(2), and one Gd(6) atom.