Li2FeAlO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form LiO5 trigonal bipyramids that share corners with two equivalent Li(1)O5 trigonal bipyramids, corners with two equivalent Li(2)O5 trigonal bipyramids, corners with four equivalent Al(1)O5 trigonal bipyramids,  an edgeedge with one Al(1)O5 trigonal bipyramid, edges with two equivalent Li(2)O5 trigonal bipyramids, and edges with three equivalent Fe(1)O5 trigonal bipyramids. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(4), and two equivalent O(3) atoms to form LiO5 trigonal bipyramids that share corners with two equivalent Li(1)O5 trigonal bipyramids, corners with two equivalent Al(1)O5 trigonal bipyramids, corners with four equivalent Fe(1)O5 trigonal bipyramids,  an edgeedge with one Li(2)O5 trigonal bipyramid,  an edgeedge with one Fe(1)O5 trigonal bipyramid, edges with two equivalent Li(1)O5 trigonal bipyramids, and edges with two equivalent Al(1)O5 trigonal bipyramids. Fe(1) is bonded to one O(1), one O(2), one O(3), and two equivalent O(4) atoms to form FeO5 trigonal bipyramids that share corners with two equivalent Fe(1)O5 trigonal bipyramids, corners with two equivalent Al(1)O5 trigonal bipyramids, corners with four equivalent Li(2)O5 trigonal bipyramids,  an edgeedge with one Li(2)O5 trigonal bipyramid, edges with two equivalent Al(1)O5 trigonal bipyramids, and edges with three equivalent Li(1)O5 trigonal bipyramids. Al(1) is bonded to one O(1), one O(3), one O(4), and two equivalent O(2) atoms to form AlO5 trigonal bipyramids that share corners with two equivalent Li(2)O5 trigonal bipyramids, corners with two equivalent Fe(1)O5 trigonal bipyramids, corners with four equivalent Li(1)O5 trigonal bipyramids,  an edgeedge with one Li(1)O5 trigonal bipyramid,  an edgeedge with one Al(1)O5 trigonal bipyramid, edges with two equivalent Li(2)O5 trigonal bipyramids, and edges with two equivalent Fe(1)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), two equivalent Li(1), one Fe(1), and one Al(1) atom to form OLi3AlFe trigonal bipyramids that share corners with two equivalent O(1)Li3AlFe trigonal bipyramids, corners with two equivalent O(3)Li3AlFe trigonal bipyramids, corners with four equivalent O(2)Li2Al2Fe trigonal bipyramids,  an edgeedge with one O(2)Li2Al2Fe trigonal bipyramid, edges with two equivalent O(3)Li3AlFe trigonal bipyramids, and edges with three equivalent O(4)Li2AlFe2 trigonal bipyramids. In the second O site, O(2) is bonded to one Li(1), one Li(2), one Fe(1), and two equivalent Al(1) atoms to form OLi2Al2Fe trigonal bipyramids that share corners with two equivalent O(4)Li2AlFe2 trigonal bipyramids, corners with two equivalent O(3)Li3AlFe trigonal bipyramids, corners with four equivalent O(1)Li3AlFe trigonal bipyramids,  an edgeedge with one O(2)Li2Al2Fe trigonal bipyramid,  an edgeedge with one O(1)Li3AlFe trigonal bipyramid, edges with two equivalent O(4)Li2AlFe2 trigonal bipyramids, and edges with two equivalent O(3)Li3AlFe trigonal bipyramids. In the third O site, O(3) is bonded to one Li(1), two equivalent Li(2), one Fe(1), and one Al(1) atom to form OLi3AlFe trigonal bipyramids that share corners with two equivalent O(2)Li2Al2Fe trigonal bipyramids, corners with two equivalent O(1)Li3AlFe trigonal bipyramids, corners with four equivalent O(4)Li2AlFe2 trigonal bipyramids,  an edgeedge with one O(4)Li2AlFe2 trigonal bipyramid,  an edgeedge with one O(3)Li3AlFe trigonal bipyramid, edges with two equivalent O(2)Li2Al2Fe trigonal bipyramids, and edges with two equivalent O(1)Li3AlFe trigonal bipyramids. In the fourth O site, O(4) is bonded to one Li(1), one Li(2), two equivalent Fe(1), and one Al(1) atom to form OLi2AlFe2 trigonal bipyramids that share corners with two equivalent O(2)Li2Al2Fe trigonal bipyramids, corners with two equivalent O(4)Li2AlFe2 trigonal bipyramids, corners with four equivalent O(3)Li3AlFe trigonal bipyramids,  an edgeedge with one O(3)Li3AlFe trigonal bipyramid, edges with two equivalent O(2)Li2Al2Fe trigonal bipyramids, and edges with three equivalent O(1)Li3AlFe trigonal bipyramids.
Li2FeAlO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form LiO5 trigonal bipyramids that share corners with two equivalent Li(1)O5 trigonal bipyramids, corners with two equivalent Li(2)O5 trigonal bipyramids, corners with four equivalent Al(1)O5 trigonal bipyramids,  an edgeedge with one Al(1)O5 trigonal bipyramid, edges with two equivalent Li(2)O5 trigonal bipyramids, and edges with three equivalent Fe(1)O5 trigonal bipyramids. The Li(1)-O(2) bond length is 2.09 Å. The Li(1)-O(3) bond length is 2.07 Å. The Li(1)-O(4) bond length is 2.11 Å. There is one shorter (2.03 Å) and one longer (2.05 Å) Li(1)-O(1) bond length. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(4), and two equivalent O(3) atoms to form LiO5 trigonal bipyramids that share corners with two equivalent Li(1)O5 trigonal bipyramids, corners with two equivalent Al(1)O5 trigonal bipyramids, corners with four equivalent Fe(1)O5 trigonal bipyramids,  an edgeedge with one Li(2)O5 trigonal bipyramid,  an edgeedge with one Fe(1)O5 trigonal bipyramid, edges with two equivalent Li(1)O5 trigonal bipyramids, and edges with two equivalent Al(1)O5 trigonal bipyramids. The Li(2)-O(1) bond length is 2.04 Å. The Li(2)-O(2) bond length is 2.10 Å. The Li(2)-O(4) bond length is 2.07 Å. There is one shorter (2.05 Å) and one longer (2.11 Å) Li(2)-O(3) bond length. Fe(1) is bonded to one O(1), one O(2), one O(3), and two equivalent O(4) atoms to form FeO5 trigonal bipyramids that share corners with two equivalent Fe(1)O5 trigonal bipyramids, corners with two equivalent Al(1)O5 trigonal bipyramids, corners with four equivalent Li(2)O5 trigonal bipyramids,  an edgeedge with one Li(2)O5 trigonal bipyramid, edges with two equivalent Al(1)O5 trigonal bipyramids, and edges with three equivalent Li(1)O5 trigonal bipyramids. The Fe(1)-O(1) bond length is 1.99 Å. The Fe(1)-O(2) bond length is 2.10 Å. The Fe(1)-O(3) bond length is 1.91 Å. There is one shorter (1.97 Å) and one longer (1.98 Å) Fe(1)-O(4) bond length. Al(1) is bonded to one O(1), one O(3), one O(4), and two equivalent O(2) atoms to form AlO5 trigonal bipyramids that share corners with two equivalent Li(2)O5 trigonal bipyramids, corners with two equivalent Fe(1)O5 trigonal bipyramids, corners with four equivalent Li(1)O5 trigonal bipyramids,  an edgeedge with one Li(1)O5 trigonal bipyramid,  an edgeedge with one Al(1)O5 trigonal bipyramid, edges with two equivalent Li(2)O5 trigonal bipyramids, and edges with two equivalent Fe(1)O5 trigonal bipyramids. The Al(1)-O(1) bond length is 1.81 Å. The Al(1)-O(3) bond length is 1.81 Å. The Al(1)-O(4) bond length is 2.00 Å. There is one shorter (1.85 Å) and one longer (1.95 Å) Al(1)-O(2) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), two equivalent Li(1), one Fe(1), and one Al(1) atom to form OLi3AlFe trigonal bipyramids that share corners with two equivalent O(1)Li3AlFe trigonal bipyramids, corners with two equivalent O(3)Li3AlFe trigonal bipyramids, corners with four equivalent O(2)Li2Al2Fe trigonal bipyramids,  an edgeedge with one O(2)Li2Al2Fe trigonal bipyramid, edges with two equivalent O(3)Li3AlFe trigonal bipyramids, and edges with three equivalent O(4)Li2AlFe2 trigonal bipyramids. In the second O site, O(2) is bonded to one Li(1), one Li(2), one Fe(1), and two equivalent Al(1) atoms to form OLi2Al2Fe trigonal bipyramids that share corners with two equivalent O(4)Li2AlFe2 trigonal bipyramids, corners with two equivalent O(3)Li3AlFe trigonal bipyramids, corners with four equivalent O(1)Li3AlFe trigonal bipyramids,  an edgeedge with one O(2)Li2Al2Fe trigonal bipyramid,  an edgeedge with one O(1)Li3AlFe trigonal bipyramid, edges with two equivalent O(4)Li2AlFe2 trigonal bipyramids, and edges with two equivalent O(3)Li3AlFe trigonal bipyramids. In the third O site, O(3) is bonded to one Li(1), two equivalent Li(2), one Fe(1), and one Al(1) atom to form OLi3AlFe trigonal bipyramids that share corners with two equivalent O(2)Li2Al2Fe trigonal bipyramids, corners with two equivalent O(1)Li3AlFe trigonal bipyramids, corners with four equivalent O(4)Li2AlFe2 trigonal bipyramids,  an edgeedge with one O(4)Li2AlFe2 trigonal bipyramid,  an edgeedge with one O(3)Li3AlFe trigonal bipyramid, edges with two equivalent O(2)Li2Al2Fe trigonal bipyramids, and edges with two equivalent O(1)Li3AlFe trigonal bipyramids. In the fourth O site, O(4) is bonded to one Li(1), one Li(2), two equivalent Fe(1), and one Al(1) atom to form OLi2AlFe2 trigonal bipyramids that share corners with two equivalent O(2)Li2Al2Fe trigonal bipyramids, corners with two equivalent O(4)Li2AlFe2 trigonal bipyramids, corners with four equivalent O(3)Li3AlFe trigonal bipyramids,  an edgeedge with one O(3)Li3AlFe trigonal bipyramid, edges with two equivalent O(2)Li2Al2Fe trigonal bipyramids, and edges with three equivalent O(1)Li3AlFe trigonal bipyramids.