KB3O5 crystallizes in the monoclinic C2/c space group. K(1) is bonded in a 5-coordinate geometry to one O(3), one O(4), one O(5), and two equivalent O(2) atoms. There are three inequivalent B sites. In the first B site, B(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing BO4 tetrahedra. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(3), one O(4), and one O(5) atom. In the third B site, B(3) is bonded to one O(2), one O(5), and two equivalent O(1) atoms to form a mixture of corner and edge-sharing BO4 tetrahedra. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one B(1) and two equivalent B(3) atoms. In the second O site, O(2) is bonded in a bent 120 degrees geometry to two equivalent K(1), one B(1), and one B(3) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one K(1), one B(1), and one B(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one K(1), one B(1), and one B(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one K(1), one B(2), and one B(3) atom.
KB3O5 crystallizes in the monoclinic C2/c space group. K(1) is bonded in a 5-coordinate geometry to one O(3), one O(4), one O(5), and two equivalent O(2) atoms. The K(1)-O(3) bond length is 2.71 Å. The K(1)-O(4) bond length is 2.87 Å. The K(1)-O(5) bond length is 2.67 Å. There is one shorter (2.79 Å) and one longer (2.82 Å) K(1)-O(2) bond length. There are three inequivalent B sites. In the first B site, B(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing BO4 tetrahedra. The B(1)-O(1) bond length is 1.54 Å. The B(1)-O(2) bond length is 1.46 Å. The B(1)-O(3) bond length is 1.48 Å. The B(1)-O(4) bond length is 1.46 Å. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(3), one O(4), and one O(5) atom. The B(2)-O(3) bond length is 1.38 Å. The B(2)-O(4) bond length is 1.38 Å. The B(2)-O(5) bond length is 1.39 Å. In the third B site, B(3) is bonded to one O(2), one O(5), and two equivalent O(1) atoms to form a mixture of corner and edge-sharing BO4 tetrahedra. The B(3)-O(2) bond length is 1.42 Å. The B(3)-O(5) bond length is 1.46 Å. There is one shorter (1.52 Å) and one longer (1.56 Å) B(3)-O(1) bond length. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one B(1) and two equivalent B(3) atoms. In the second O site, O(2) is bonded in a bent 120 degrees geometry to two equivalent K(1), one B(1), and one B(3) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one K(1), one B(1), and one B(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one K(1), one B(1), and one B(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one K(1), one B(2), and one B(3) atom.