Li4Nb(FeO4)3 is Ilmenite-derived structured and crystallizes in the monoclinic P2 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form distorted LiO6 pentagonal pyramids that share corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent Fe(3)O6 octahedra,  an edgeedge with one Nb(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and faces with two equivalent Li(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 42-60°. In the second Li site, Li(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form distorted LiO6 pentagonal pyramids that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Fe(2)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and faces with two equivalent Li(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 40-60°. In the third Li site, Li(3) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms. In the fourth Li site, Li(4) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms. Nb(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form NbO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Li(2)O6 pentagonal pyramids, edges with two equivalent Fe(2)O6 octahedra, and  an edgeedge with one Li(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles are 45°. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Li(1)O6 pentagonal pyramids, edges with two equivalent Fe(3)O6 octahedra, and  an edgeedge with one Li(2)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles are 45°. In the second Fe site, Fe(2) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms to form FeO6 octahedra that share corners with two equivalent Fe(3)O6 octahedra, corners with four equivalent Li(2)O6 pentagonal pyramids, edges with two equivalent Nb(1)O6 octahedra, and edges with two equivalent Li(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 48°. In the third Fe site, Fe(3) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form FeO6 octahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with four equivalent Li(1)O6 pentagonal pyramids, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Li(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 48°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Li(3), one Li(4), one Nb(1), and one Fe(1) atom. In the second O site, O(2) is bonded to one Li(1), one Li(2), one Fe(1), and one Fe(3) atom to form distorted OLi2Fe2 trigonal pyramids that share corners with two equivalent O(2)Li2Fe2 trigonal pyramids, corners with two equivalent O(4)Li2Fe2 trigonal pyramids, corners with two equivalent O(3)Li2NbFe trigonal pyramids,  an edgeedge with one O(2)Li2Fe2 trigonal pyramid,  an edgeedge with one O(4)Li2Fe2 trigonal pyramid, and  an edgeedge with one O(3)Li2NbFe trigonal pyramid. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Nb(1), and one Fe(2) atom to form distorted OLi2NbFe trigonal pyramids that share corners with two equivalent O(2)Li2Fe2 trigonal pyramids, corners with two equivalent O(3)Li2NbFe trigonal pyramids,  an edgeedge with one O(2)Li2Fe2 trigonal pyramid, and  an edgeedge with one O(3)Li2NbFe trigonal pyramid. In the fourth O site, O(4) is bonded to one Li(3), one Li(4), one Fe(1), and one Fe(3) atom to form a mixture of distorted corner and edge-sharing OLi2Fe2 trigonal pyramids. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Li(3), one Li(4), one Nb(1), and one Fe(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Fe(2), and one Fe(3) atom.
Li4Nb(FeO4)3 is Ilmenite-derived structured and crystallizes in the monoclinic P2 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form distorted LiO6 pentagonal pyramids that share corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent Fe(3)O6 octahedra,  an edgeedge with one Nb(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and faces with two equivalent Li(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 42-60°. Both Li(1)-O(2) bond lengths are 2.02 Å. Both Li(1)-O(3) bond lengths are 2.19 Å. Both Li(1)-O(6) bond lengths are 2.14 Å. In the second Li site, Li(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form distorted LiO6 pentagonal pyramids that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Fe(2)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and faces with two equivalent Li(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 40-60°. Both Li(2)-O(2) bond lengths are 2.22 Å. Both Li(2)-O(3) bond lengths are 1.98 Å. Both Li(2)-O(6) bond lengths are 2.21 Å. In the third Li site, Li(3) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms. Both Li(3)-O(1) bond lengths are 2.24 Å. Both Li(3)-O(4) bond lengths are 1.98 Å. Both Li(3)-O(5) bond lengths are 2.42 Å. In the fourth Li site, Li(4) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms. Both Li(4)-O(1) bond lengths are 2.21 Å. Both Li(4)-O(4) bond lengths are 2.30 Å. Both Li(4)-O(5) bond lengths are 1.95 Å. Nb(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form NbO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Li(2)O6 pentagonal pyramids, edges with two equivalent Fe(2)O6 octahedra, and  an edgeedge with one Li(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles are 45°. Both Nb(1)-O(1) bond lengths are 1.96 Å. Both Nb(1)-O(3) bond lengths are 2.08 Å. Both Nb(1)-O(5) bond lengths are 1.99 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Li(1)O6 pentagonal pyramids, edges with two equivalent Fe(3)O6 octahedra, and  an edgeedge with one Li(2)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles are 45°. Both Fe(1)-O(1) bond lengths are 1.91 Å. Both Fe(1)-O(2) bond lengths are 1.91 Å. Both Fe(1)-O(4) bond lengths are 1.88 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms to form FeO6 octahedra that share corners with two equivalent Fe(3)O6 octahedra, corners with four equivalent Li(2)O6 pentagonal pyramids, edges with two equivalent Nb(1)O6 octahedra, and edges with two equivalent Li(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 48°. Both Fe(2)-O(3) bond lengths are 1.85 Å. Both Fe(2)-O(5) bond lengths are 1.94 Å. Both Fe(2)-O(6) bond lengths are 1.94 Å. In the third Fe site, Fe(3) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form FeO6 octahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with four equivalent Li(1)O6 pentagonal pyramids, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Li(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 48°. Both Fe(3)-O(2) bond lengths are 1.88 Å. Both Fe(3)-O(4) bond lengths are 1.95 Å. Both Fe(3)-O(6) bond lengths are 1.89 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Li(3), one Li(4), one Nb(1), and one Fe(1) atom. In the second O site, O(2) is bonded to one Li(1), one Li(2), one Fe(1), and one Fe(3) atom to form distorted OLi2Fe2 trigonal pyramids that share corners with two equivalent O(2)Li2Fe2 trigonal pyramids, corners with two equivalent O(4)Li2Fe2 trigonal pyramids, corners with two equivalent O(3)Li2NbFe trigonal pyramids,  an edgeedge with one O(2)Li2Fe2 trigonal pyramid,  an edgeedge with one O(4)Li2Fe2 trigonal pyramid, and  an edgeedge with one O(3)Li2NbFe trigonal pyramid. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Nb(1), and one Fe(2) atom to form distorted OLi2NbFe trigonal pyramids that share corners with two equivalent O(2)Li2Fe2 trigonal pyramids, corners with two equivalent O(3)Li2NbFe trigonal pyramids,  an edgeedge with one O(2)Li2Fe2 trigonal pyramid, and  an edgeedge with one O(3)Li2NbFe trigonal pyramid. In the fourth O site, O(4) is bonded to one Li(3), one Li(4), one Fe(1), and one Fe(3) atom to form a mixture of distorted corner and edge-sharing OLi2Fe2 trigonal pyramids. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Li(3), one Li(4), one Nb(1), and one Fe(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Li(1), one Li(2), one Fe(2), and one Fe(3) atom.