LiEr4Zr4O14 crystallizes in the monoclinic Pm space group. Li(1) is bonded in a 6-coordinate geometry to one O(8), one O(9), two equivalent O(10), and two equivalent O(5) atoms. There are four inequivalent Er sites. In the first Er site, Er(1) is bonded in a 6-coordinate geometry to one O(1), one O(13), two equivalent O(10), and two equivalent O(2) atoms. In the second Er site, Er(2) is bonded in a 6-coordinate geometry to one O(12), one O(14), one O(2), one O(7), and two equivalent O(3) atoms. In the third Er site, Er(3) is bonded to one O(1), one O(13), two equivalent O(11), and two equivalent O(12) atoms to form distorted ErO6 octahedra that share edges with two equivalent Zr(1)O7 hexagonal pyramids, edges with two equivalent Zr(2)O7 hexagonal pyramids, and edges with two equivalent Er(3)O6 octahedra. In the fourth Er site, Er(4) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(5), one O(6), and two equivalent O(9) atoms. There are four inequivalent Zr sites. In the first Zr site, Zr(1) is bonded to one O(10), one O(11), one O(6), two equivalent O(1), and two equivalent O(8) atoms to form distorted ZrO7 hexagonal pyramids that share edges with two equivalent Zr(1)O7 hexagonal pyramids and edges with two equivalent Er(3)O6 octahedra. In the second Zr site, Zr(2) is bonded to one O(12), one O(14), one O(7), two equivalent O(13), and two equivalent O(4) atoms to form distorted ZrO7 hexagonal pyramids that share edges with two equivalent Zr(2)O7 hexagonal pyramids and edges with two equivalent Er(3)O6 octahedra. In the third Zr site, Zr(3) is bonded in a 6-coordinate geometry to one O(3), one O(4), one O(9), two equivalent O(5), and two equivalent O(7) atoms. In the fourth Zr site, Zr(4) is bonded in a 7-coordinate geometry to one O(3), one O(4), one O(9), two equivalent O(14), and two equivalent O(6) atoms. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded to one Er(1), one Er(3), and two equivalent Zr(1) atoms to form OEr2Zr2 tetrahedra that share corners with two equivalent O(1)Er2Zr2 tetrahedra, corners with two equivalent O(13)Er2Zr2 tetrahedra, corners with two equivalent O(12)Er3Zr tetrahedra, corners with two equivalent O(6)ErZr3 tetrahedra, and edges with two equivalent O(11)Er3Zr tetrahedra. In the second O site, O(2) is bonded in a trigonal planar geometry to one Er(2) and two equivalent Er(1) atoms. In the third O site, O(3) is bonded to two equivalent Er(2), one Zr(3), and one Zr(4) atom to form OEr2Zr2 tetrahedra that share corners with two equivalent O(3)Er2Zr2 tetrahedra, corners with two equivalent O(12)Er3Zr tetrahedra, corners with two equivalent O(6)ErZr3 tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra, edges with two equivalent O(14)ErZr3 tetrahedra, and edges with two equivalent O(7)ErZr3 tetrahedra. In the fourth O site, O(4) is bonded to one Zr(3), one Zr(4), and two equivalent Zr(2) atoms to form OZr4 tetrahedra that share corners with two equivalent O(13)Er2Zr2 tetrahedra, corners with two equivalent O(3)Er2Zr2 tetrahedra, corners with two equivalent O(12)Er3Zr tetrahedra, corners with two equivalent O(6)ErZr3 tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra,  an edgeedge with one O(13)Er2Zr2 tetrahedra, edges with two equivalent O(14)ErZr3 tetrahedra, and edges with two equivalent O(7)ErZr3 tetrahedra. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to two equivalent Li(1), one Er(4), and two equivalent Zr(3) atoms. In the sixth O site, O(6) is bonded to one Er(4), one Zr(1), and two equivalent Zr(4) atoms to form distorted OErZr3 tetrahedra that share corners with two equivalent O(1)Er2Zr2 tetrahedra, corners with two equivalent O(3)Er2Zr2 tetrahedra, corners with two equivalent O(14)ErZr3 tetrahedra, corners with two equivalent O(6)ErZr3 tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra,  an edgeedge with one O(11)Er3Zr tetrahedra, and  an edgeedge with one O(14)ErZr3 tetrahedra. In the seventh O site, O(7) is bonded to one Er(2), one Zr(2), and two equivalent Zr(3) atoms to form distorted OErZr3 tetrahedra that share corners with two equivalent O(13)Er2Zr2 tetrahedra, corners with two equivalent O(12)Er3Zr tetrahedra, corners with two equivalent O(14)ErZr3 tetrahedra, corners with two equivalent O(7)ErZr3 tetrahedra, edges with two equivalent O(3)Er2Zr2 tetrahedra, and edges with two equivalent O(4)Zr4 tetrahedra. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Li(1) and two equivalent Zr(1) atoms. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Li(1), two equivalent Er(4), one Zr(3), and one Zr(4) atom. In the tenth O site, O(10) is bonded in a 6-coordinate geometry to two equivalent Li(1), one Er(4), two equivalent Er(1), and one Zr(1) atom. In the eleventh O site, O(11) is bonded to one Er(4), two equivalent Er(3), and one Zr(1) atom to form OEr3Zr tetrahedra that share corners with two equivalent O(13)Er2Zr2 tetrahedra, corners with two equivalent O(11)Er3Zr tetrahedra, corners with two equivalent O(12)Er3Zr tetrahedra,  an edgeedge with one O(12)Er3Zr tetrahedra,  an edgeedge with one O(6)ErZr3 tetrahedra, and edges with two equivalent O(1)Er2Zr2 tetrahedra. In the twelfth O site, O(12) is bonded to one Er(2), two equivalent Er(3), and one Zr(2) atom to form OEr3Zr tetrahedra that share corners with two equivalent O(1)Er2Zr2 tetrahedra, corners with two equivalent O(3)Er2Zr2 tetrahedra, corners with two equivalent O(11)Er3Zr tetrahedra, corners with two equivalent O(12)Er3Zr tetrahedra, corners with two equivalent O(7)ErZr3 tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra,  an edgeedge with one O(11)Er3Zr tetrahedra,  an edgeedge with one O(14)ErZr3 tetrahedra, and edges with two equivalent O(13)Er2Zr2 tetrahedra. In the thirteenth O site, O(13) is bonded to one Er(1), one Er(3), and two equivalent Zr(2) atoms to form OEr2Zr2 tetrahedra that share corners with two equivalent O(1)Er2Zr2 tetrahedra, corners with two equivalent O(13)Er2Zr2 tetrahedra, corners with two equivalent O(11)Er3Zr tetrahedra, corners with two equivalent O(14)ErZr3 tetrahedra, corners with two equivalent O(7)ErZr3 tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra,  an edgeedge with one O(4)Zr4 tetrahedra, and edges with two equivalent O(12)Er3Zr tetrahedra. In the fourteenth O site, O(14) is bonded to one Er(2), one Zr(2), and two equivalent Zr(4) atoms to form OErZr3 tetrahedra that share corners with two equivalent O(13)Er2Zr2 tetrahedra, corners with two equivalent O(14)ErZr3 tetrahedra, corners with two equivalent O(6)ErZr3 tetrahedra, corners with two equivalent O(7)ErZr3 tetrahedra,  an edgeedge with one O(12)Er3Zr tetrahedra,  an edgeedge with one O(6)ErZr3 tetrahedra, edges with two equivalent O(3)Er2Zr2 tetrahedra, and edges with two equivalent O(4)Zr4 tetrahedra.
LiEr4Zr4O14 crystallizes in the monoclinic Pm space group. Li(1) is bonded in a 6-coordinate geometry to one O(8), one O(9), two equivalent O(10), and two equivalent O(5) atoms. The Li(1)-O(8) bond length is 1.85 Å. The Li(1)-O(9) bond length is 2.38 Å. Both Li(1)-O(10) bond lengths are 2.07 Å. Both Li(1)-O(5) bond lengths are 2.45 Å. There are four inequivalent Er sites. In the first Er site, Er(1) is bonded in a 6-coordinate geometry to one O(1), one O(13), two equivalent O(10), and two equivalent O(2) atoms. The Er(1)-O(1) bond length is 2.21 Å. The Er(1)-O(13) bond length is 2.47 Å. Both Er(1)-O(10) bond lengths are 2.54 Å. Both Er(1)-O(2) bond lengths are 2.16 Å. In the second Er site, Er(2) is bonded in a 6-coordinate geometry to one O(12), one O(14), one O(2), one O(7), and two equivalent O(3) atoms. The Er(2)-O(12) bond length is 2.37 Å. The Er(2)-O(14) bond length is 2.29 Å. The Er(2)-O(2) bond length is 2.17 Å. The Er(2)-O(7) bond length is 2.23 Å. Both Er(2)-O(3) bond lengths are 2.21 Å. In the third Er site, Er(3) is bonded to one O(1), one O(13), two equivalent O(11), and two equivalent O(12) atoms to form distorted ErO6 octahedra that share edges with two equivalent Zr(1)O7 hexagonal pyramids, edges with two equivalent Zr(2)O7 hexagonal pyramids, and edges with two equivalent Er(3)O6 octahedra. The Er(3)-O(1) bond length is 2.21 Å. The Er(3)-O(13) bond length is 2.36 Å. Both Er(3)-O(11) bond lengths are 2.30 Å. Both Er(3)-O(12) bond lengths are 2.29 Å. In the fourth Er site, Er(4) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(5), one O(6), and two equivalent O(9) atoms. The Er(4)-O(10) bond length is 2.29 Å. The Er(4)-O(11) bond length is 2.17 Å. The Er(4)-O(5) bond length is 2.63 Å. The Er(4)-O(6) bond length is 2.37 Å. Both Er(4)-O(9) bond lengths are 2.14 Å. There are four inequivalent Zr sites. In the first Zr site, Zr(1) is bonded to one O(10), one O(11), one O(6), two equivalent O(1), and two equivalent O(8) atoms to form distorted ZrO7 hexagonal pyramids that share edges with two equivalent Zr(1)O7 hexagonal pyramids and edges with two equivalent Er(3)O6 octahedra. The Zr(1)-O(10) bond length is 2.28 Å. The Zr(1)-O(11) bond length is 2.14 Å. The Zr(1)-O(6) bond length is 2.24 Å. Both Zr(1)-O(1) bond lengths are 2.30 Å. Both Zr(1)-O(8) bond lengths are 2.14 Å. In the second Zr site, Zr(2) is bonded to one O(12), one O(14), one O(7), two equivalent O(13), and two equivalent O(4) atoms to form distorted ZrO7 hexagonal pyramids that share edges with two equivalent Zr(2)O7 hexagonal pyramids and edges with two equivalent Er(3)O6 octahedra. The Zr(2)-O(12) bond length is 2.21 Å. The Zr(2)-O(14) bond length is 2.16 Å. The Zr(2)-O(7) bond length is 2.13 Å. Both Zr(2)-O(13) bond lengths are 2.22 Å. Both Zr(2)-O(4) bond lengths are 2.26 Å. In the third Zr site, Zr(3) is bonded in a 6-coordinate geometry to one O(3), one O(4), one O(9), two equivalent O(5), and two equivalent O(7) atoms. The Zr(3)-O(3) bond length is 2.19 Å. The Zr(3)-O(4) bond length is 2.14 Å. The Zr(3)-O(9) bond length is 2.56 Å. Both Zr(3)-O(5) bond lengths are 2.08 Å. Both Zr(3)-O(7) bond lengths are 2.33 Å. In the fourth Zr site, Zr(4) is bonded in a 7-coordinate geometry to one O(3), one O(4), one O(9), two equivalent O(14), and two equivalent O(6) atoms. The Zr(4)-O(3) bond length is 2.37 Å. The Zr(4)-O(4) bond length is 2.19 Å. The Zr(4)-O(9) bond length is 2.17 Å. Both Zr(4)-O(14) bond lengths are 2.22 Å. Both Zr(4)-O(6) bond lengths are 2.18 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded to one Er(1), one Er(3), and two equivalent Zr(1) atoms to form OEr2Zr2 tetrahedra that share corners with two equivalent O(1)Er2Zr2 tetrahedra, corners with two equivalent O(13)Er2Zr2 tetrahedra, corners with two equivalent O(12)Er3Zr tetrahedra, corners with two equivalent O(6)ErZr3 tetrahedra, and edges with two equivalent O(11)Er3Zr tetrahedra. In the second O site, O(2) is bonded in a trigonal planar geometry to one Er(2) and two equivalent Er(1) atoms. In the third O site, O(3) is bonded to two equivalent Er(2), one Zr(3), and one Zr(4) atom to form OEr2Zr2 tetrahedra that share corners with two equivalent O(3)Er2Zr2 tetrahedra, corners with two equivalent O(12)Er3Zr tetrahedra, corners with two equivalent O(6)ErZr3 tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra, edges with two equivalent O(14)ErZr3 tetrahedra, and edges with two equivalent O(7)ErZr3 tetrahedra. In the fourth O site, O(4) is bonded to one Zr(3), one Zr(4), and two equivalent Zr(2) atoms to form OZr4 tetrahedra that share corners with two equivalent O(13)Er2Zr2 tetrahedra, corners with two equivalent O(3)Er2Zr2 tetrahedra, corners with two equivalent O(12)Er3Zr tetrahedra, corners with two equivalent O(6)ErZr3 tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra,  an edgeedge with one O(13)Er2Zr2 tetrahedra, edges with two equivalent O(14)ErZr3 tetrahedra, and edges with two equivalent O(7)ErZr3 tetrahedra. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to two equivalent Li(1), one Er(4), and two equivalent Zr(3) atoms. In the sixth O site, O(6) is bonded to one Er(4), one Zr(1), and two equivalent Zr(4) atoms to form distorted OErZr3 tetrahedra that share corners with two equivalent O(1)Er2Zr2 tetrahedra, corners with two equivalent O(3)Er2Zr2 tetrahedra, corners with two equivalent O(14)ErZr3 tetrahedra, corners with two equivalent O(6)ErZr3 tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra,  an edgeedge with one O(11)Er3Zr tetrahedra, and  an edgeedge with one O(14)ErZr3 tetrahedra. In the seventh O site, O(7) is bonded to one Er(2), one Zr(2), and two equivalent Zr(3) atoms to form distorted OErZr3 tetrahedra that share corners with two equivalent O(13)Er2Zr2 tetrahedra, corners with two equivalent O(12)Er3Zr tetrahedra, corners with two equivalent O(14)ErZr3 tetrahedra, corners with two equivalent O(7)ErZr3 tetrahedra, edges with two equivalent O(3)Er2Zr2 tetrahedra, and edges with two equivalent O(4)Zr4 tetrahedra. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Li(1) and two equivalent Zr(1) atoms. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Li(1), two equivalent Er(4), one Zr(3), and one Zr(4) atom. In the tenth O site, O(10) is bonded in a 6-coordinate geometry to two equivalent Li(1), one Er(4), two equivalent Er(1), and one Zr(1) atom. In the eleventh O site, O(11) is bonded to one Er(4), two equivalent Er(3), and one Zr(1) atom to form OEr3Zr tetrahedra that share corners with two equivalent O(13)Er2Zr2 tetrahedra, corners with two equivalent O(11)Er3Zr tetrahedra, corners with two equivalent O(12)Er3Zr tetrahedra,  an edgeedge with one O(12)Er3Zr tetrahedra,  an edgeedge with one O(6)ErZr3 tetrahedra, and edges with two equivalent O(1)Er2Zr2 tetrahedra. In the twelfth O site, O(12) is bonded to one Er(2), two equivalent Er(3), and one Zr(2) atom to form OEr3Zr tetrahedra that share corners with two equivalent O(1)Er2Zr2 tetrahedra, corners with two equivalent O(3)Er2Zr2 tetrahedra, corners with two equivalent O(11)Er3Zr tetrahedra, corners with two equivalent O(12)Er3Zr tetrahedra, corners with two equivalent O(7)ErZr3 tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra,  an edgeedge with one O(11)Er3Zr tetrahedra,  an edgeedge with one O(14)ErZr3 tetrahedra, and edges with two equivalent O(13)Er2Zr2 tetrahedra. In the thirteenth O site, O(13) is bonded to one Er(1), one Er(3), and two equivalent Zr(2) atoms to form OEr2Zr2 tetrahedra that share corners with two equivalent O(1)Er2Zr2 tetrahedra, corners with two equivalent O(13)Er2Zr2 tetrahedra, corners with two equivalent O(11)Er3Zr tetrahedra, corners with two equivalent O(14)ErZr3 tetrahedra, corners with two equivalent O(7)ErZr3 tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra,  an edgeedge with one O(4)Zr4 tetrahedra, and edges with two equivalent O(12)Er3Zr tetrahedra. In the fourteenth O site, O(14) is bonded to one Er(2), one Zr(2), and two equivalent Zr(4) atoms to form OErZr3 tetrahedra that share corners with two equivalent O(13)Er2Zr2 tetrahedra, corners with two equivalent O(14)ErZr3 tetrahedra, corners with two equivalent O(6)ErZr3 tetrahedra, corners with two equivalent O(7)ErZr3 tetrahedra,  an edgeedge with one O(12)Er3Zr tetrahedra,  an edgeedge with one O(6)ErZr3 tetrahedra, edges with two equivalent O(3)Er2Zr2 tetrahedra, and edges with two equivalent O(4)Zr4 tetrahedra.