K4Li3Mn2O8 crystallizes in the monoclinic Pc space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(7), one O(8), and two equivalent O(4) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(2), and two equivalent O(6) atoms. In the third K site, K(3) is bonded in a 6-coordinate geometry to one O(3), one O(4), one O(5), one O(6), and two equivalent O(7) atoms. In the fourth K site, K(4) is bonded in a 6-coordinate geometry to one O(7), one O(8), two equivalent O(1), and two equivalent O(5) atoms. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(8) atom. In the second Li site, Li(2) is bonded to one O(3), one O(5), one O(6), and one O(8) atom to form distorted LiO4 tetrahedra that share corners with two equivalent Mn(1)O4 tetrahedra and  an edgeedge with one Mn(2)O4 tetrahedra. In the third Li site, Li(3) is bonded in a 4-coordinate geometry to one O(4), one O(5), one O(6), and one O(8) atom. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(2), one O(6), one O(7), and one O(8) atom to form MnO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra. In the second Mn site, Mn(2) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form MnO4 tetrahedra that share  an edgeedge with one Li(2)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one K(1), two equivalent K(4), one Li(1), and one Mn(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one K(1), two equivalent K(2), one Li(1), and one Mn(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one K(2), one K(3), one Li(1), one Li(2), and one Mn(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one K(2), one K(3), two equivalent K(1), one Li(3), and one Mn(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one K(3), two equivalent K(4), one Li(2), one Li(3), and one Mn(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one K(3), two equivalent K(2), one Li(2), one Li(3), and one Mn(1) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one K(1), one K(4), two equivalent K(3), and one Mn(1) atom. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one K(1), one K(4), one Li(1), one Li(2), one Li(3), and one Mn(1) atom.
K4Li3Mn2O8 crystallizes in the monoclinic Pc space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(7), one O(8), and two equivalent O(4) atoms. The K(1)-O(1) bond length is 2.58 Å. The K(1)-O(2) bond length is 2.77 Å. The K(1)-O(7) bond length is 3.01 Å. The K(1)-O(8) bond length is 2.74 Å. There is one shorter (2.85 Å) and one longer (3.00 Å) K(1)-O(4) bond length. In the second K site, K(2) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(2), and two equivalent O(6) atoms. The K(2)-O(3) bond length is 2.65 Å. The K(2)-O(4) bond length is 2.75 Å. There is one shorter (2.71 Å) and one longer (3.11 Å) K(2)-O(2) bond length. There is one shorter (2.84 Å) and one longer (3.03 Å) K(2)-O(6) bond length. In the third K site, K(3) is bonded in a 6-coordinate geometry to one O(3), one O(4), one O(5), one O(6), and two equivalent O(7) atoms. The K(3)-O(3) bond length is 2.72 Å. The K(3)-O(4) bond length is 3.21 Å. The K(3)-O(5) bond length is 2.76 Å. The K(3)-O(6) bond length is 2.81 Å. There is one shorter (2.98 Å) and one longer (3.10 Å) K(3)-O(7) bond length. In the fourth K site, K(4) is bonded in a 6-coordinate geometry to one O(7), one O(8), two equivalent O(1), and two equivalent O(5) atoms. The K(4)-O(7) bond length is 2.72 Å. The K(4)-O(8) bond length is 2.79 Å. There is one shorter (2.78 Å) and one longer (3.08 Å) K(4)-O(1) bond length. There is one shorter (2.93 Å) and one longer (2.99 Å) K(4)-O(5) bond length. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(8) atom. The Li(1)-O(1) bond length is 1.89 Å. The Li(1)-O(2) bond length is 1.98 Å. The Li(1)-O(3) bond length is 1.93 Å. The Li(1)-O(8) bond length is 2.25 Å. In the second Li site, Li(2) is bonded to one O(3), one O(5), one O(6), and one O(8) atom to form distorted LiO4 tetrahedra that share corners with two equivalent Mn(1)O4 tetrahedra and  an edgeedge with one Mn(2)O4 tetrahedra. The Li(2)-O(3) bond length is 1.94 Å. The Li(2)-O(5) bond length is 1.96 Å. The Li(2)-O(6) bond length is 2.00 Å. The Li(2)-O(8) bond length is 2.00 Å. In the third Li site, Li(3) is bonded in a 4-coordinate geometry to one O(4), one O(5), one O(6), and one O(8) atom. The Li(3)-O(4) bond length is 1.96 Å. The Li(3)-O(5) bond length is 1.96 Å. The Li(3)-O(6) bond length is 2.17 Å. The Li(3)-O(8) bond length is 2.09 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(2), one O(6), one O(7), and one O(8) atom to form MnO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra. The Mn(1)-O(2) bond length is 1.71 Å. The Mn(1)-O(6) bond length is 1.75 Å. The Mn(1)-O(7) bond length is 1.69 Å. The Mn(1)-O(8) bond length is 1.76 Å. In the second Mn site, Mn(2) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form MnO4 tetrahedra that share  an edgeedge with one Li(2)O4 tetrahedra. The Mn(2)-O(1) bond length is 1.79 Å. The Mn(2)-O(3) bond length is 1.81 Å. The Mn(2)-O(4) bond length is 1.84 Å. The Mn(2)-O(5) bond length is 1.86 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one K(1), two equivalent K(4), one Li(1), and one Mn(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one K(1), two equivalent K(2), one Li(1), and one Mn(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one K(2), one K(3), one Li(1), one Li(2), and one Mn(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one K(2), one K(3), two equivalent K(1), one Li(3), and one Mn(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one K(3), two equivalent K(4), one Li(2), one Li(3), and one Mn(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one K(3), two equivalent K(2), one Li(2), one Li(3), and one Mn(1) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one K(1), one K(4), two equivalent K(3), and one Mn(1) atom. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one K(1), one K(4), one Li(1), one Li(2), one Li(3), and one Mn(1) atom.