The material structure described by Gd2ZrSe5 crystallizes in the triclinic P1 space group. There are eight inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 8-coordinate geometry to one Se(1), one Se(12), one Se(14), one Se(16), one Se(17), one Se(20), one Se(4), and one Se(9) atom. In the second Gd site, Gd(2) is bonded in a 8-coordinate geometry to one Se(10), one Se(11), one Se(13), one Se(15), one Se(18), one Se(19), one Se(2), and one Se(3) atom. In the third Gd site, Gd(3) is bonded in a 8-coordinate geometry to one Se(10), one Se(11), one Se(14), one Se(16), one Se(18), one Se(19), one Se(2), and one Se(3) atom. In the fourth Gd site, Gd(4) is bonded in a 8-coordinate geometry to one Se(1), one Se(12), one Se(13), one Se(15), one Se(17), one Se(20), one Se(4), and one Se(9) atom. In the fifth Gd site, Gd(5) is bonded in a 8-coordinate geometry to one Se(10), one Se(11), one Se(14), one Se(16), one Se(18), one Se(19), one Se(5), and one Se(8) atom. In the sixth Gd site, Gd(6) is bonded in a 8-coordinate geometry to one Se(12), one Se(13), one Se(15), one Se(17), one Se(20), one Se(6), one Se(7), and one Se(9) atom. In the seventh Gd site, Gd(7) is bonded in a 8-coordinate geometry to one Se(12), one Se(14), one Se(16), one Se(17), one Se(20), one Se(6), one Se(7), and one Se(9) atom. In the eighth Gd site, Gd(8) is bonded in a 8-coordinate geometry to one Se(10), one Se(11), one Se(13), one Se(15), one Se(18), one Se(19), one Se(5), and one Se(8) atom. There are four inequivalent Zr sites. In the first Zr site, Zr(1) is bonded to one Se(14), one Se(18), one Se(2), one Se(4), one Se(6), one Se(8), and one Se(9) atom to form distorted edge-sharing ZrSe7 pentagonal bipyramids. In the second Zr site, Zr(2) is bonded to one Se(1), one Se(10), one Se(13), one Se(17), one Se(3), one Se(5), and one Se(7) atom to form distorted edge-sharing ZrSe7 pentagonal bipyramids. In the third Zr site, Zr(3) is bonded to one Se(11), one Se(16), one Se(2), one Se(20), one Se(4), one Se(6), and one Se(8) atom to form distorted edge-sharing ZrSe7 pentagonal bipyramids. In the fourth Zr site, Zr(4) is bonded to one Se(1), one Se(12), one Se(15), one Se(19), one Se(3), one Se(5), and one Se(7) atom to form distorted edge-sharing ZrSe7 pentagonal bipyramids. There are twenty inequivalent Se sites. In the first Se site, Se(1) is bonded to one Gd(1), one Gd(4), one Zr(2), and one Zr(4) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(14)Gd4Zr square pyramid,  a cornercorner with one Se(16)Gd4Zr square pyramid, corners with two equivalent Se(13)Gd4Zr square pyramids,  a cornercorner with one Se(10)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(12)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(17)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(19)Gd4Zr trigonal bipyramid, corners with two equivalent Se(3)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(4)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(7)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(15)Gd4Zr square pyramid,  an edgeedge with one Se(12)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(17)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(20)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(9)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(5)Gd2Zr2 trigonal pyramid. In the second Se site, Se(2) is bonded to one Gd(2), one Gd(3), one Zr(1), and one Zr(3) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(13)Gd4Zr square pyramid,  a cornercorner with one Se(15)Gd4Zr square pyramid, corners with two equivalent Se(14)Gd4Zr square pyramids,  a cornercorner with one Se(11)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(18)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(20)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(9)Gd4Zr trigonal bipyramid, corners with two equivalent Se(3)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(4)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(8)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(16)Gd4Zr square pyramid,  an edgeedge with one Se(10)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(11)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(18)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(19)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(6)Gd2Zr2 trigonal pyramid. In the third Se site, Se(3) is bonded to one Gd(2), one Gd(3), one Zr(2), and one Zr(4) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(14)Gd4Zr square pyramid,  a cornercorner with one Se(16)Gd4Zr square pyramid, corners with two equivalent Se(15)Gd4Zr square pyramids,  a cornercorner with one Se(10)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(12)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(17)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(19)Gd4Zr trigonal bipyramid, corners with two equivalent Se(1)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(2)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(5)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(13)Gd4Zr square pyramid,  an edgeedge with one Se(10)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(11)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(18)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(19)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(7)Gd2Zr2 trigonal pyramid. In the fourth Se site, Se(4) is bonded to one Gd(1), one Gd(4), one Zr(1), and one Zr(3) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(13)Gd4Zr square pyramid,  a cornercorner with one Se(15)Gd4Zr square pyramid, corners with two equivalent Se(16)Gd4Zr square pyramids,  a cornercorner with one Se(11)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(18)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(20)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(9)Gd4Zr trigonal bipyramid, corners with two equivalent Se(1)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(2)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(6)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(14)Gd4Zr square pyramid,  an edgeedge with one Se(12)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(17)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(20)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(9)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(8)Gd2Zr2 trigonal pyramid. In the fifth Se site, Se(5) is bonded to one Gd(5), one Gd(8), one Zr(2), and one Zr(4) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(14)Gd4Zr square pyramid,  a cornercorner with one Se(16)Gd4Zr square pyramid, corners with two equivalent Se(15)Gd4Zr square pyramids,  a cornercorner with one Se(10)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(12)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(17)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(19)Gd4Zr trigonal bipyramid, corners with two equivalent Se(3)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(7)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(8)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(13)Gd4Zr square pyramid,  an edgeedge with one Se(10)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(11)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(18)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(19)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(1)Gd2Zr2 trigonal pyramid. In the sixth Se site, Se(6) is bonded to one Gd(6), one Gd(7), one Zr(1), and one Zr(3) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(13)Gd4Zr square pyramid,  a cornercorner with one Se(15)Gd4Zr square pyramid, corners with two equivalent Se(16)Gd4Zr square pyramids,  a cornercorner with one Se(11)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(18)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(20)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(9)Gd4Zr trigonal bipyramid, corners with two equivalent Se(4)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(7)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(8)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(14)Gd4Zr square pyramid,  an edgeedge with one Se(12)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(17)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(20)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(9)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(2)Gd2Zr2 trigonal pyramid. In the seventh Se site, Se(7) is bonded to one Gd(6), one Gd(7), one Zr(2), and one Zr(4) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(14)Gd4Zr square pyramid,  a cornercorner with one Se(16)Gd4Zr square pyramid, corners with two equivalent Se(13)Gd4Zr square pyramids,  a cornercorner with one Se(10)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(12)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(17)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(19)Gd4Zr trigonal bipyramid, corners with two equivalent Se(1)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(5)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(6)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(15)Gd4Zr square pyramid,  an edgeedge with one Se(12)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(17)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(20)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(9)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(3)Gd2Zr2 trigonal pyramid. In the eighth Se site, Se(8) is bonded to one Gd(5), one Gd(8), one Zr(1), and one Zr(3) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(13)Gd4Zr square pyramid,  a cornercorner with one Se(15)Gd4Zr square pyramid, corners with two equivalent Se(14)Gd4Zr square pyramids,  a cornercorner with one Se(11)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(18)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(20)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(9)Gd4Zr trigonal bipyramid, corners with two equivalent Se(2)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(5)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(6)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(16)Gd4Zr square pyramid,  an edgeedge with one Se(10)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(11)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(18)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(19)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(4)Gd2Zr2 trigonal pyramid. In the ninth Se site, Se(9) is bonded to one Gd(1), one Gd(4), one Gd(6), one Gd(7), and one Zr(1) atom to form distorted SeGd4Zr trigonal bipyramids that share  a cornercorner with one Se(14)Gd4Zr square pyramid, corners with two equivalent Se(15)Gd4Zr square pyramids, corners with two equivalent Se(16)Gd4Zr square pyramids,  a cornercorner with one Se(18)Gd4Zr trigonal bipyramid, corners with four equivalent Se(12)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(2)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(4)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(6)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(8)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(13)Gd4Zr square pyramid,  an edgeedge with one Se(14)Gd4Zr square pyramid, edges with two equivalent Se(17)Gd4Zr trigonal bipyramids, edges with two equivalent Se(20)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(1)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(4)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(6)Gd2Zr2 trigonal pyramid, and  an edgeedge with one Se(7)Gd2Zr2 trigonal pyramid. In the tenth Se site, Se(10) is bonded to one Gd(2), one Gd(3), one Gd(5), one Gd(8), and one Zr(2) atom to form distorted SeGd4Zr trigonal bipyramids that share  a cornercorner with one Se(13)Gd4Zr square pyramid, corners with two equivalent Se(15)Gd4Zr square pyramids, corners with two equivalent Se(16)Gd4Zr square pyramids,  a cornercorner with one Se(17)Gd4Zr trigonal bipyramid, corners with four equivalent Se(11)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(1)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(3)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(5)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(7)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(13)Gd4Zr square pyramid,  an edgeedge with one Se(14)Gd4Zr square pyramid, edges with two equivalent Se(18)Gd4Zr trigonal bipyramids, edges with two equivalent Se(19)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(2)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(3)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(5)Gd2Zr2 trigonal pyramid, and  an edgeedge with one Se(8)Gd2Zr2 trigonal pyramid. In the eleventh Se site, Se(11) is bonded to one Gd(2), one Gd(3), one Gd(5), one Gd(8), and one Zr(3) atom to form distorted SeGd4Zr trigonal bipyramids that share  a cornercorner with one Se(16)Gd4Zr square pyramid, corners with two equivalent Se(13)Gd4Zr square pyramids, corners with two equivalent Se(14)Gd4Zr square pyramids,  a cornercorner with one Se(20)Gd4Zr trigonal bipyramid, corners with four equivalent Se(10)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(2)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(4)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(6)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(8)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(15)Gd4Zr square pyramid,  an edgeedge with one Se(16)Gd4Zr square pyramid, edges with two equivalent Se(18)Gd4Zr trigonal bipyramids, edges with two equivalent Se(19)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(2)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(3)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(5)Gd2Zr2 trigonal pyramid, and  an edgeedge with one Se(8)Gd2Zr2 trigonal pyramid. In the twelfth Se site, Se(12) is bonded to one Gd(1), one Gd(4), one Gd(6), one Gd(7), and one Zr(4) atom to form distorted SeGd4Zr trigonal bipyramids that share  a cornercorner with one Se(15)Gd4Zr square pyramid, corners with two equivalent Se(13)Gd4Zr square pyramids, corners with two equivalent Se(14)Gd4Zr square pyramids,  a cornercorner with one Se(19)Gd4Zr trigonal bipyramid, corners with four equivalent Se(9)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(1)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(3)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(5)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(7)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(15)Gd4Zr square pyramid,  an edgeedge with one Se(16)Gd4Zr square pyramid, edges with two equivalent Se(17)Gd4Zr trigonal bipyramids, edges with two equivalent Se(20)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(1)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(4)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(6)Gd2Zr2 trigonal pyramid, and  an edgeedge with one Se(7)Gd2Zr2 trigonal pyramid. In the thirteenth Se site, Se(13) is bonded to one Gd(2), one Gd(4), one Gd(6), one Gd(8), and one Zr(2) atom to form SeGd4Zr square pyramids that share  a cornercorner with one Se(10)Gd4Zr trigonal bipyramid, corners with two equivalent Se(11)Gd4Zr trigonal bipyramids, corners with two equivalent Se(12)Gd4Zr trigonal bipyramids, corners with two equivalent Se(19)Gd4Zr trigonal bipyramids, corners with two equivalent Se(20)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(2)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(4)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(6)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(8)Gd2Zr2 trigonal pyramid, corners with two equivalent Se(1)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(7)Gd2Zr2 trigonal pyramids, edges with two equivalent Se(15)Gd4Zr square pyramids,  an edgeedge with one Se(10)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(18)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(9)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(3)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(5)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(17)Gd4Zr trigonal bipyramid. In the fourteenth Se site, Se(14) is bonded to one Gd(1), one Gd(3), one Gd(5), one Gd(7), and one Zr(1) atom to form SeGd4Zr square pyramids that share  a cornercorner with one Se(9)Gd4Zr trigonal bipyramid, corners with two equivalent Se(11)Gd4Zr trigonal bipyramids, corners with two equivalent Se(12)Gd4Zr trigonal bipyramids, corners with two equivalent Se(19)Gd4Zr trigonal bipyramids, corners with two equivalent Se(20)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(1)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(3)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(5)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(7)Gd2Zr2 trigonal pyramid, corners with two equivalent Se(2)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(8)Gd2Zr2 trigonal pyramids, edges with two equivalent Se(16)Gd4Zr square pyramids,  an edgeedge with one Se(10)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(17)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(9)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(4)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(6)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(18)Gd4Zr trigonal bipyramid. In the fifteenth Se site, Se(15) is bonded to one Gd(2), one Gd(4), one Gd(6), one Gd(8), and one Zr(4) atom to form SeGd4Zr square pyramids that share  a cornercorner with one Se(12)Gd4Zr trigonal bipyramid, corners with two equivalent Se(10)Gd4Zr trigonal bipyramids, corners with two equivalent Se(17)Gd4Zr trigonal bipyramids, corners with two equivalent Se(18)Gd4Zr trigonal bipyramids, corners with two equivalent Se(9)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(2)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(4)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(6)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(8)Gd2Zr2 trigonal pyramid, corners with two equivalent Se(3)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(5)Gd2Zr2 trigonal pyramids, edges with two equivalent Se(13)Gd4Zr square pyramids,  an edgeedge with one Se(11)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(12)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(20)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(1)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(7)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(19)Gd4Zr trigonal bipyramid. In the sixteenth Se site, Se(16) is bonded to one Gd(1), one Gd(3), one Gd(5), one Gd(7), and one Zr(3) atom to form SeGd4Zr square pyramids that share  a cornercorner with one Se(11)Gd4Zr trigonal bipyramid, corners with two equivalent Se(10)Gd4Zr trigonal bipyramids, corners with two equivalent Se(17)Gd4Zr trigonal bipyramids, corners with two equivalent Se(18)Gd4Zr trigonal bipyramids, corners with two equivalent Se(9)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(1)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(3)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(5)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(7)Gd2Zr2 trigonal pyramid, corners with two equivalent Se(4)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(6)Gd2Zr2 trigonal pyramids, edges with two equivalent Se(14)Gd4Zr square pyramids,  an edgeedge with one Se(11)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(12)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(19)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(2)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(8)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(20)Gd4Zr trigonal bipyramid. In the seventeenth Se site, Se(17) is bonded to one Gd(1), one Gd(4), one Gd(6), one Gd(7), and one Zr(2) atom to form distorted SeGd4Zr trigonal bipyramids that share corners with two equivalent Se(15)Gd4Zr square pyramids, corners with two equivalent Se(16)Gd4Zr square pyramids,  a cornercorner with one Se(10)Gd4Zr trigonal bipyramid, corners with four equivalent Se(20)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(1)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(3)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(5)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(7)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(14)Gd4Zr square pyramid, edges with two equivalent Se(12)Gd4Zr trigonal bipyramids, edges with two equivalent Se(9)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(1)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(4)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(6)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(7)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(13)Gd4Zr square pyramid. In the eighteenth Se site, Se(18) is bonded to one Gd(2), one Gd(3), one Gd(5), one Gd(8), and one Zr(1) atom to form distorted SeGd4Zr trigonal bipyramids that share corners with two equivalent Se(15)Gd4Zr square pyramids, corners with two equivalent Se(16)Gd4Zr square pyramids,  a cornercorner with one Se(9)Gd4Zr trigonal bipyramid, corners with four equivalent Se(19)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(2)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(4)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(6)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(8)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(13)Gd4Zr square pyramid, edges with two equivalent Se(10)Gd4Zr trigonal bipyramids, edges with two equivalent Se(11)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(2)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(3)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(5)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(8)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(14)Gd4Zr square pyramid. In the nineteenth Se site, Se(19) is bonded to one Gd(2), one Gd(3), one Gd(5), one Gd(8), and one Zr(4) atom to form distorted SeGd4Zr trigonal bipyramids that share corners with two equivalent Se(13)Gd4Zr square pyramids, corners with two equivalent Se(14)Gd4Zr square pyramids,  a cornercorner with one Se(12)Gd4Zr trigonal bipyramid, corners with four equivalent Se(18)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(1)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(3)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(5)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(7)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(16)Gd4Zr square pyramid, edges with two equivalent Se(10)Gd4Zr trigonal bipyramids, edges with two equivalent Se(11)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(2)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(3)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(5)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(8)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(15)Gd4Zr square pyramid. In the twentieth Se site, Se(20) is bonded to one Gd(1), one Gd(4), one Gd(6), one Gd(7), and one Zr(3) atom to form distorted SeGd4Zr trigonal bipyramids that share corners with two equivalent Se(13)Gd4Zr square pyramids, corners with two equivalent Se(14)Gd4Zr square pyramids,  a cornercorner with one Se(11)Gd4Zr trigonal bipyramid, corners with four equivalent Se(17)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(2)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(4)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(6)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(8)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(15)Gd4Zr square pyramid, edges with two equivalent Se(12)Gd4Zr trigonal bipyramids, edges with two equivalent Se(9)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(1)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(4)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(6)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(7)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(16)Gd4Zr square pyramid. is represented by the CIF file [CIF]
data_Gd2ZrSe5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.650
_cell_length_b   8.169
_cell_length_c   12.166
_cell_angle_alpha   90.008
_cell_angle_beta   89.999
_cell_angle_gamma   89.986
_symmetry_Int_Tables_number   1
_cell_volume   760.287
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Gd  Gd0  1  0.976  0.003  0.179  1.0
  Gd  Gd1  1  0.524  0.497  0.679  1.0
  Gd  Gd2  1  0.024  0.503  0.821  1.0
  Gd  Gd3  1  0.476  0.997  0.321  1.0
  Gd  Gd4  1  0.025  0.997  0.821  1.0
  Gd  Gd5  1  0.475  0.504  0.321  1.0
  Gd  Gd6  1  0.975  0.496  0.179  1.0
  Gd  Gd7  1  0.525  0.004  0.679  1.0
  Zr  Zr8  1  0.421  0.750  0.006  1.0
  Zr  Zr9  1  0.079  0.750  0.506  1.0
  Zr  Zr10  1  0.579  0.250  0.994  1.0
  Zr  Zr11  1  0.921  0.250  0.494  1.0
  Se  Se12  1  0.838  0.963  0.407  1.0
  Se  Se13  1  0.663  0.537  0.908  1.0
  Se  Se14  1  0.162  0.463  0.592  1.0
  Se  Se15  1  0.338  0.037  0.093  1.0
  Se  Se16  1  0.163  0.037  0.592  1.0
  Se  Se17  1  0.338  0.463  0.093  1.0
  Se  Se18  1  0.837  0.537  0.407  1.0
  Se  Se19  1  0.663  0.962  0.908  1.0
  Se  Se20  1  0.666  0.750  0.181  1.0
  Se  Se21  1  0.835  0.750  0.682  1.0
  Se  Se22  1  0.334  0.249  0.819  1.0
  Se  Se23  1  0.166  0.250  0.319  1.0
  Se  Se24  1  0.450  0.751  0.503  1.0
  Se  Se25  1  0.050  0.750  0.004  1.0
  Se  Se26  1  0.550  0.250  0.496  1.0
  Se  Se27  1  0.950  0.250  0.996  1.0
  Se  Se28  1  0.188  0.750  0.292  1.0
  Se  Se29  1  0.312  0.750  0.792  1.0
  Se  Se30  1  0.813  0.250  0.708  1.0
  Se  Se31  1  0.688  0.250  0.208  1.0
[/CIF]
.
The material structure described by Gd2ZrSe5 crystallizes in the triclinic P1 space group. There are eight inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 8-coordinate geometry to one Se(1), one Se(12), one Se(14), one Se(16), one Se(17), one Se(20), one Se(4), and one Se(9) atom. In the second Gd site, Gd(2) is bonded in a 8-coordinate geometry to one Se(10), one Se(11), one Se(13), one Se(15), one Se(18), one Se(19), one Se(2), and one Se(3) atom. In the third Gd site, Gd(3) is bonded in a 8-coordinate geometry to one Se(10), one Se(11), one Se(14), one Se(16), one Se(18), one Se(19), one Se(2), and one Se(3) atom. In the fourth Gd site, Gd(4) is bonded in a 8-coordinate geometry to one Se(1), one Se(12), one Se(13), one Se(15), one Se(17), one Se(20), one Se(4), and one Se(9) atom. In the fifth Gd site, Gd(5) is bonded in a 8-coordinate geometry to one Se(10), one Se(11), one Se(14), one Se(16), one Se(18), one Se(19), one Se(5), and one Se(8) atom. In the sixth Gd site, Gd(6) is bonded in a 8-coordinate geometry to one Se(12), one Se(13), one Se(15), one Se(17), one Se(20), one Se(6), one Se(7), and one Se(9) atom. In the seventh Gd site, Gd(7) is bonded in a 8-coordinate geometry to one Se(12), one Se(14), one Se(16), one Se(17), one Se(20), one Se(6), one Se(7), and one Se(9) atom. In the eighth Gd site, Gd(8) is bonded in a 8-coordinate geometry to one Se(10), one Se(11), one Se(13), one Se(15), one Se(18), one Se(19), one Se(5), and one Se(8) atom. There are four inequivalent Zr sites. In the first Zr site, Zr(1) is bonded to one Se(14), one Se(18), one Se(2), one Se(4), one Se(6), one Se(8), and one Se(9) atom to form distorted edge-sharing ZrSe7 pentagonal bipyramids. In the second Zr site, Zr(2) is bonded to one Se(1), one Se(10), one Se(13), one Se(17), one Se(3), one Se(5), and one Se(7) atom to form distorted edge-sharing ZrSe7 pentagonal bipyramids. In the third Zr site, Zr(3) is bonded to one Se(11), one Se(16), one Se(2), one Se(20), one Se(4), one Se(6), and one Se(8) atom to form distorted edge-sharing ZrSe7 pentagonal bipyramids. In the fourth Zr site, Zr(4) is bonded to one Se(1), one Se(12), one Se(15), one Se(19), one Se(3), one Se(5), and one Se(7) atom to form distorted edge-sharing ZrSe7 pentagonal bipyramids. There are twenty inequivalent Se sites. In the first Se site, Se(1) is bonded to one Gd(1), one Gd(4), one Zr(2), and one Zr(4) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(14)Gd4Zr square pyramid,  a cornercorner with one Se(16)Gd4Zr square pyramid, corners with two equivalent Se(13)Gd4Zr square pyramids,  a cornercorner with one Se(10)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(12)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(17)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(19)Gd4Zr trigonal bipyramid, corners with two equivalent Se(3)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(4)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(7)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(15)Gd4Zr square pyramid,  an edgeedge with one Se(12)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(17)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(20)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(9)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(5)Gd2Zr2 trigonal pyramid. In the second Se site, Se(2) is bonded to one Gd(2), one Gd(3), one Zr(1), and one Zr(3) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(13)Gd4Zr square pyramid,  a cornercorner with one Se(15)Gd4Zr square pyramid, corners with two equivalent Se(14)Gd4Zr square pyramids,  a cornercorner with one Se(11)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(18)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(20)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(9)Gd4Zr trigonal bipyramid, corners with two equivalent Se(3)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(4)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(8)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(16)Gd4Zr square pyramid,  an edgeedge with one Se(10)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(11)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(18)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(19)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(6)Gd2Zr2 trigonal pyramid. In the third Se site, Se(3) is bonded to one Gd(2), one Gd(3), one Zr(2), and one Zr(4) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(14)Gd4Zr square pyramid,  a cornercorner with one Se(16)Gd4Zr square pyramid, corners with two equivalent Se(15)Gd4Zr square pyramids,  a cornercorner with one Se(10)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(12)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(17)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(19)Gd4Zr trigonal bipyramid, corners with two equivalent Se(1)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(2)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(5)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(13)Gd4Zr square pyramid,  an edgeedge with one Se(10)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(11)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(18)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(19)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(7)Gd2Zr2 trigonal pyramid. In the fourth Se site, Se(4) is bonded to one Gd(1), one Gd(4), one Zr(1), and one Zr(3) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(13)Gd4Zr square pyramid,  a cornercorner with one Se(15)Gd4Zr square pyramid, corners with two equivalent Se(16)Gd4Zr square pyramids,  a cornercorner with one Se(11)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(18)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(20)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(9)Gd4Zr trigonal bipyramid, corners with two equivalent Se(1)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(2)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(6)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(14)Gd4Zr square pyramid,  an edgeedge with one Se(12)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(17)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(20)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(9)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(8)Gd2Zr2 trigonal pyramid. In the fifth Se site, Se(5) is bonded to one Gd(5), one Gd(8), one Zr(2), and one Zr(4) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(14)Gd4Zr square pyramid,  a cornercorner with one Se(16)Gd4Zr square pyramid, corners with two equivalent Se(15)Gd4Zr square pyramids,  a cornercorner with one Se(10)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(12)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(17)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(19)Gd4Zr trigonal bipyramid, corners with two equivalent Se(3)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(7)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(8)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(13)Gd4Zr square pyramid,  an edgeedge with one Se(10)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(11)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(18)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(19)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(1)Gd2Zr2 trigonal pyramid. In the sixth Se site, Se(6) is bonded to one Gd(6), one Gd(7), one Zr(1), and one Zr(3) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(13)Gd4Zr square pyramid,  a cornercorner with one Se(15)Gd4Zr square pyramid, corners with two equivalent Se(16)Gd4Zr square pyramids,  a cornercorner with one Se(11)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(18)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(20)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(9)Gd4Zr trigonal bipyramid, corners with two equivalent Se(4)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(7)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(8)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(14)Gd4Zr square pyramid,  an edgeedge with one Se(12)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(17)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(20)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(9)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(2)Gd2Zr2 trigonal pyramid. In the seventh Se site, Se(7) is bonded to one Gd(6), one Gd(7), one Zr(2), and one Zr(4) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(14)Gd4Zr square pyramid,  a cornercorner with one Se(16)Gd4Zr square pyramid, corners with two equivalent Se(13)Gd4Zr square pyramids,  a cornercorner with one Se(10)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(12)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(17)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(19)Gd4Zr trigonal bipyramid, corners with two equivalent Se(1)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(5)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(6)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(15)Gd4Zr square pyramid,  an edgeedge with one Se(12)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(17)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(20)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(9)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(3)Gd2Zr2 trigonal pyramid. In the eighth Se site, Se(8) is bonded to one Gd(5), one Gd(8), one Zr(1), and one Zr(3) atom to form distorted SeGd2Zr2 trigonal pyramids that share  a cornercorner with one Se(13)Gd4Zr square pyramid,  a cornercorner with one Se(15)Gd4Zr square pyramid, corners with two equivalent Se(14)Gd4Zr square pyramids,  a cornercorner with one Se(11)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(18)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(20)Gd4Zr trigonal bipyramid,  a cornercorner with one Se(9)Gd4Zr trigonal bipyramid, corners with two equivalent Se(2)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(5)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(6)Gd2Zr2 trigonal pyramids,  an edgeedge with one Se(16)Gd4Zr square pyramid,  an edgeedge with one Se(10)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(11)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(18)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(19)Gd4Zr trigonal bipyramid, and  an edgeedge with one Se(4)Gd2Zr2 trigonal pyramid. In the ninth Se site, Se(9) is bonded to one Gd(1), one Gd(4), one Gd(6), one Gd(7), and one Zr(1) atom to form distorted SeGd4Zr trigonal bipyramids that share  a cornercorner with one Se(14)Gd4Zr square pyramid, corners with two equivalent Se(15)Gd4Zr square pyramids, corners with two equivalent Se(16)Gd4Zr square pyramids,  a cornercorner with one Se(18)Gd4Zr trigonal bipyramid, corners with four equivalent Se(12)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(2)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(4)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(6)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(8)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(13)Gd4Zr square pyramid,  an edgeedge with one Se(14)Gd4Zr square pyramid, edges with two equivalent Se(17)Gd4Zr trigonal bipyramids, edges with two equivalent Se(20)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(1)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(4)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(6)Gd2Zr2 trigonal pyramid, and  an edgeedge with one Se(7)Gd2Zr2 trigonal pyramid. In the tenth Se site, Se(10) is bonded to one Gd(2), one Gd(3), one Gd(5), one Gd(8), and one Zr(2) atom to form distorted SeGd4Zr trigonal bipyramids that share  a cornercorner with one Se(13)Gd4Zr square pyramid, corners with two equivalent Se(15)Gd4Zr square pyramids, corners with two equivalent Se(16)Gd4Zr square pyramids,  a cornercorner with one Se(17)Gd4Zr trigonal bipyramid, corners with four equivalent Se(11)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(1)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(3)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(5)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(7)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(13)Gd4Zr square pyramid,  an edgeedge with one Se(14)Gd4Zr square pyramid, edges with two equivalent Se(18)Gd4Zr trigonal bipyramids, edges with two equivalent Se(19)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(2)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(3)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(5)Gd2Zr2 trigonal pyramid, and  an edgeedge with one Se(8)Gd2Zr2 trigonal pyramid. In the eleventh Se site, Se(11) is bonded to one Gd(2), one Gd(3), one Gd(5), one Gd(8), and one Zr(3) atom to form distorted SeGd4Zr trigonal bipyramids that share  a cornercorner with one Se(16)Gd4Zr square pyramid, corners with two equivalent Se(13)Gd4Zr square pyramids, corners with two equivalent Se(14)Gd4Zr square pyramids,  a cornercorner with one Se(20)Gd4Zr trigonal bipyramid, corners with four equivalent Se(10)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(2)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(4)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(6)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(8)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(15)Gd4Zr square pyramid,  an edgeedge with one Se(16)Gd4Zr square pyramid, edges with two equivalent Se(18)Gd4Zr trigonal bipyramids, edges with two equivalent Se(19)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(2)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(3)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(5)Gd2Zr2 trigonal pyramid, and  an edgeedge with one Se(8)Gd2Zr2 trigonal pyramid. In the twelfth Se site, Se(12) is bonded to one Gd(1), one Gd(4), one Gd(6), one Gd(7), and one Zr(4) atom to form distorted SeGd4Zr trigonal bipyramids that share  a cornercorner with one Se(15)Gd4Zr square pyramid, corners with two equivalent Se(13)Gd4Zr square pyramids, corners with two equivalent Se(14)Gd4Zr square pyramids,  a cornercorner with one Se(19)Gd4Zr trigonal bipyramid, corners with four equivalent Se(9)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(1)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(3)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(5)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(7)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(15)Gd4Zr square pyramid,  an edgeedge with one Se(16)Gd4Zr square pyramid, edges with two equivalent Se(17)Gd4Zr trigonal bipyramids, edges with two equivalent Se(20)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(1)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(4)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(6)Gd2Zr2 trigonal pyramid, and  an edgeedge with one Se(7)Gd2Zr2 trigonal pyramid. In the thirteenth Se site, Se(13) is bonded to one Gd(2), one Gd(4), one Gd(6), one Gd(8), and one Zr(2) atom to form SeGd4Zr square pyramids that share  a cornercorner with one Se(10)Gd4Zr trigonal bipyramid, corners with two equivalent Se(11)Gd4Zr trigonal bipyramids, corners with two equivalent Se(12)Gd4Zr trigonal bipyramids, corners with two equivalent Se(19)Gd4Zr trigonal bipyramids, corners with two equivalent Se(20)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(2)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(4)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(6)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(8)Gd2Zr2 trigonal pyramid, corners with two equivalent Se(1)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(7)Gd2Zr2 trigonal pyramids, edges with two equivalent Se(15)Gd4Zr square pyramids,  an edgeedge with one Se(10)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(18)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(9)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(3)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(5)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(17)Gd4Zr trigonal bipyramid. In the fourteenth Se site, Se(14) is bonded to one Gd(1), one Gd(3), one Gd(5), one Gd(7), and one Zr(1) atom to form SeGd4Zr square pyramids that share  a cornercorner with one Se(9)Gd4Zr trigonal bipyramid, corners with two equivalent Se(11)Gd4Zr trigonal bipyramids, corners with two equivalent Se(12)Gd4Zr trigonal bipyramids, corners with two equivalent Se(19)Gd4Zr trigonal bipyramids, corners with two equivalent Se(20)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(1)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(3)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(5)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(7)Gd2Zr2 trigonal pyramid, corners with two equivalent Se(2)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(8)Gd2Zr2 trigonal pyramids, edges with two equivalent Se(16)Gd4Zr square pyramids,  an edgeedge with one Se(10)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(17)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(9)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(4)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(6)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(18)Gd4Zr trigonal bipyramid. In the fifteenth Se site, Se(15) is bonded to one Gd(2), one Gd(4), one Gd(6), one Gd(8), and one Zr(4) atom to form SeGd4Zr square pyramids that share  a cornercorner with one Se(12)Gd4Zr trigonal bipyramid, corners with two equivalent Se(10)Gd4Zr trigonal bipyramids, corners with two equivalent Se(17)Gd4Zr trigonal bipyramids, corners with two equivalent Se(18)Gd4Zr trigonal bipyramids, corners with two equivalent Se(9)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(2)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(4)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(6)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(8)Gd2Zr2 trigonal pyramid, corners with two equivalent Se(3)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(5)Gd2Zr2 trigonal pyramids, edges with two equivalent Se(13)Gd4Zr square pyramids,  an edgeedge with one Se(11)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(12)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(20)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(1)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(7)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(19)Gd4Zr trigonal bipyramid. In the sixteenth Se site, Se(16) is bonded to one Gd(1), one Gd(3), one Gd(5), one Gd(7), and one Zr(3) atom to form SeGd4Zr square pyramids that share  a cornercorner with one Se(11)Gd4Zr trigonal bipyramid, corners with two equivalent Se(10)Gd4Zr trigonal bipyramids, corners with two equivalent Se(17)Gd4Zr trigonal bipyramids, corners with two equivalent Se(18)Gd4Zr trigonal bipyramids, corners with two equivalent Se(9)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(1)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(3)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(5)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(7)Gd2Zr2 trigonal pyramid, corners with two equivalent Se(4)Gd2Zr2 trigonal pyramids, corners with two equivalent Se(6)Gd2Zr2 trigonal pyramids, edges with two equivalent Se(14)Gd4Zr square pyramids,  an edgeedge with one Se(11)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(12)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(19)Gd4Zr trigonal bipyramid,  an edgeedge with one Se(2)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(8)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(20)Gd4Zr trigonal bipyramid. In the seventeenth Se site, Se(17) is bonded to one Gd(1), one Gd(4), one Gd(6), one Gd(7), and one Zr(2) atom to form distorted SeGd4Zr trigonal bipyramids that share corners with two equivalent Se(15)Gd4Zr square pyramids, corners with two equivalent Se(16)Gd4Zr square pyramids,  a cornercorner with one Se(10)Gd4Zr trigonal bipyramid, corners with four equivalent Se(20)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(1)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(3)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(5)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(7)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(14)Gd4Zr square pyramid, edges with two equivalent Se(12)Gd4Zr trigonal bipyramids, edges with two equivalent Se(9)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(1)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(4)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(6)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(7)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(13)Gd4Zr square pyramid. In the eighteenth Se site, Se(18) is bonded to one Gd(2), one Gd(3), one Gd(5), one Gd(8), and one Zr(1) atom to form distorted SeGd4Zr trigonal bipyramids that share corners with two equivalent Se(15)Gd4Zr square pyramids, corners with two equivalent Se(16)Gd4Zr square pyramids,  a cornercorner with one Se(9)Gd4Zr trigonal bipyramid, corners with four equivalent Se(19)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(2)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(4)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(6)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(8)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(13)Gd4Zr square pyramid, edges with two equivalent Se(10)Gd4Zr trigonal bipyramids, edges with two equivalent Se(11)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(2)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(3)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(5)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(8)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(14)Gd4Zr square pyramid. In the nineteenth Se site, Se(19) is bonded to one Gd(2), one Gd(3), one Gd(5), one Gd(8), and one Zr(4) atom to form distorted SeGd4Zr trigonal bipyramids that share corners with two equivalent Se(13)Gd4Zr square pyramids, corners with two equivalent Se(14)Gd4Zr square pyramids,  a cornercorner with one Se(12)Gd4Zr trigonal bipyramid, corners with four equivalent Se(18)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(1)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(3)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(5)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(7)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(16)Gd4Zr square pyramid, edges with two equivalent Se(10)Gd4Zr trigonal bipyramids, edges with two equivalent Se(11)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(2)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(3)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(5)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(8)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(15)Gd4Zr square pyramid. In the twentieth Se site, Se(20) is bonded to one Gd(1), one Gd(4), one Gd(6), one Gd(7), and one Zr(3) atom to form distorted SeGd4Zr trigonal bipyramids that share corners with two equivalent Se(13)Gd4Zr square pyramids, corners with two equivalent Se(14)Gd4Zr square pyramids,  a cornercorner with one Se(11)Gd4Zr trigonal bipyramid, corners with four equivalent Se(17)Gd4Zr trigonal bipyramids,  a cornercorner with one Se(2)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(4)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(6)Gd2Zr2 trigonal pyramid,  a cornercorner with one Se(8)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(15)Gd4Zr square pyramid, edges with two equivalent Se(12)Gd4Zr trigonal bipyramids, edges with two equivalent Se(9)Gd4Zr trigonal bipyramids,  an edgeedge with one Se(1)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(4)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(6)Gd2Zr2 trigonal pyramid,  an edgeedge with one Se(7)Gd2Zr2 trigonal pyramid, and  a faceface with one Se(16)Gd4Zr square pyramid. is represented by the CIF file [CIF]
data_Gd2ZrSe5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.650
_cell_length_b   8.169
_cell_length_c   12.166
_cell_angle_alpha   90.008
_cell_angle_beta   89.999
_cell_angle_gamma   89.986
_symmetry_Int_Tables_number   1
_cell_volume   760.287
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Gd  Gd0  1  0.976  0.003  0.179  1.0
  Gd  Gd1  1  0.524  0.497  0.679  1.0
  Gd  Gd2  1  0.024  0.503  0.821  1.0
  Gd  Gd3  1  0.476  0.997  0.321  1.0
  Gd  Gd4  1  0.025  0.997  0.821  1.0
  Gd  Gd5  1  0.475  0.504  0.321  1.0
  Gd  Gd6  1  0.975  0.496  0.179  1.0
  Gd  Gd7  1  0.525  0.004  0.679  1.0
  Zr  Zr8  1  0.421  0.750  0.006  1.0
  Zr  Zr9  1  0.079  0.750  0.506  1.0
  Zr  Zr10  1  0.579  0.250  0.994  1.0
  Zr  Zr11  1  0.921  0.250  0.494  1.0
  Se  Se12  1  0.838  0.963  0.407  1.0
  Se  Se13  1  0.663  0.537  0.908  1.0
  Se  Se14  1  0.162  0.463  0.592  1.0
  Se  Se15  1  0.338  0.037  0.093  1.0
  Se  Se16  1  0.163  0.037  0.592  1.0
  Se  Se17  1  0.338  0.463  0.093  1.0
  Se  Se18  1  0.837  0.537  0.407  1.0
  Se  Se19  1  0.663  0.962  0.908  1.0
  Se  Se20  1  0.666  0.750  0.181  1.0
  Se  Se21  1  0.835  0.750  0.682  1.0
  Se  Se22  1  0.334  0.249  0.819  1.0
  Se  Se23  1  0.166  0.250  0.319  1.0
  Se  Se24  1  0.450  0.751  0.503  1.0
  Se  Se25  1  0.050  0.750  0.004  1.0
  Se  Se26  1  0.550  0.250  0.496  1.0
  Se  Se27  1  0.950  0.250  0.996  1.0
  Se  Se28  1  0.188  0.750  0.292  1.0
  Se  Se29  1  0.312  0.750  0.792  1.0
  Se  Se30  1  0.813  0.250  0.708  1.0
  Se  Se31  1  0.688  0.250  0.208  1.0
[/CIF]
.