K2Ge3(BO5)2 crystallizes in the monoclinic C2 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 10-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(6), one O(8), and three equivalent O(9) atoms. In the second K site, K(2) is bonded in a 9-coordinate geometry to one O(1), one O(4), one O(6), one O(8), two equivalent O(7), and three equivalent O(5) atoms. There are two inequivalent B sites. In the first B site, B(1) is bonded to one O(2), one O(5), one O(7), and one O(8) atom to form BO4 tetrahedra that share  a cornercorner with one Ge(2)O4 tetrahedra,  a cornercorner with one Ge(4)O4 tetrahedra, and corners with two equivalent Ge(3)O4 tetrahedra. In the second B site, B(2) is bonded to one O(10), one O(3), one O(4), and one O(9) atom to form BO4 tetrahedra that share  a cornercorner with one Ge(1)O4 tetrahedra,  a cornercorner with one Ge(3)O4 tetrahedra, and corners with two equivalent Ge(2)O4 tetrahedra. There are four inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to two equivalent O(4) and two equivalent O(6) atoms to form GeO4 tetrahedra that share corners with two equivalent B(2)O4 tetrahedra and corners with two equivalent Ge(2)O4 tetrahedra. In the second Ge site, Ge(2) is bonded to one O(10), one O(3), one O(5), and one O(6) atom to form GeO4 tetrahedra that share  a cornercorner with one B(1)O4 tetrahedra,  a cornercorner with one Ge(1)O4 tetrahedra, and corners with two equivalent B(2)O4 tetrahedra. In the third Ge site, Ge(3) is bonded to one O(1), one O(2), one O(7), and one O(9) atom to form GeO4 tetrahedra that share  a cornercorner with one B(2)O4 tetrahedra,  a cornercorner with one Ge(4)O4 tetrahedra, and corners with two equivalent B(1)O4 tetrahedra. In the fourth Ge site, Ge(4) is bonded to two equivalent O(1) and two equivalent O(8) atoms to form GeO4 tetrahedra that share corners with two equivalent B(1)O4 tetrahedra and corners with two equivalent Ge(3)O4 tetrahedra. There are ten inequivalent O sites. In the first O site, O(5) is bonded in a distorted bent 120 degrees geometry to three equivalent K(2), one B(1), and one Ge(2) atom. In the second O site, O(6) is bonded in a distorted bent 120 degrees geometry to one K(1), one K(2), one Ge(1), and one Ge(2) atom. In the third O site, O(7) is bonded in a distorted bent 120 degrees geometry to two equivalent K(2), one B(1), and one Ge(3) atom. In the fourth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one K(1), one K(2), one B(1), and one Ge(4) atom. In the fifth O site, O(9) is bonded in a 2-coordinate geometry to three equivalent K(1), one B(2), and one Ge(3) atom. In the sixth O site, O(10) is bonded in a bent 120 degrees geometry to one K(1), one B(2), and one Ge(2) atom. In the seventh O site, O(1) is bonded in a 2-coordinate geometry to one K(1), one K(2), one Ge(3), and one Ge(4) atom. In the eighth O site, O(2) is bonded in a distorted bent 120 degrees geometry to one K(1), one B(1), and one Ge(3) atom. In the ninth O site, O(3) is bonded in a distorted bent 120 degrees geometry to one K(1), one B(2), and one Ge(2) atom. In the tenth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one K(1), one K(2), one B(2), and one Ge(1) atom.
K2Ge3(BO5)2 crystallizes in the monoclinic C2 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 10-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(6), one O(8), and three equivalent O(9) atoms. The K(1)-O(1) bond length is 2.77 Å. The K(1)-O(10) bond length is 3.07 Å. The K(1)-O(2) bond length is 2.99 Å. The K(1)-O(3) bond length is 3.00 Å. The K(1)-O(4) bond length is 2.99 Å. The K(1)-O(6) bond length is 3.04 Å. The K(1)-O(8) bond length is 3.38 Å. There are a spread of K(1)-O(9) bond distances ranging from 2.76-3.18 Å. In the second K site, K(2) is bonded in a 9-coordinate geometry to one O(1), one O(4), one O(6), one O(8), two equivalent O(7), and three equivalent O(5) atoms. The K(2)-O(1) bond length is 3.16 Å. The K(2)-O(4) bond length is 2.95 Å. The K(2)-O(6) bond length is 2.95 Å. The K(2)-O(8) bond length is 2.90 Å. There is one shorter (2.86 Å) and one longer (3.25 Å) K(2)-O(7) bond length. There are a spread of K(2)-O(5) bond distances ranging from 2.77-3.20 Å. There are two inequivalent B sites. In the first B site, B(1) is bonded to one O(2), one O(5), one O(7), and one O(8) atom to form BO4 tetrahedra that share  a cornercorner with one Ge(2)O4 tetrahedra,  a cornercorner with one Ge(4)O4 tetrahedra, and corners with two equivalent Ge(3)O4 tetrahedra. The B(1)-O(2) bond length is 1.49 Å. The B(1)-O(5) bond length is 1.49 Å. The B(1)-O(7) bond length is 1.50 Å. The B(1)-O(8) bond length is 1.49 Å. In the second B site, B(2) is bonded to one O(10), one O(3), one O(4), and one O(9) atom to form BO4 tetrahedra that share  a cornercorner with one Ge(1)O4 tetrahedra,  a cornercorner with one Ge(3)O4 tetrahedra, and corners with two equivalent Ge(2)O4 tetrahedra. The B(2)-O(10) bond length is 1.50 Å. The B(2)-O(3) bond length is 1.48 Å. The B(2)-O(4) bond length is 1.50 Å. The B(2)-O(9) bond length is 1.49 Å. There are four inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to two equivalent O(4) and two equivalent O(6) atoms to form GeO4 tetrahedra that share corners with two equivalent B(2)O4 tetrahedra and corners with two equivalent Ge(2)O4 tetrahedra. Both Ge(1)-O(4) bond lengths are 1.75 Å. Both Ge(1)-O(6) bond lengths are 1.79 Å. In the second Ge site, Ge(2) is bonded to one O(10), one O(3), one O(5), and one O(6) atom to form GeO4 tetrahedra that share  a cornercorner with one B(1)O4 tetrahedra,  a cornercorner with one Ge(1)O4 tetrahedra, and corners with two equivalent B(2)O4 tetrahedra. The Ge(2)-O(10) bond length is 1.77 Å. The Ge(2)-O(3) bond length is 1.77 Å. The Ge(2)-O(5) bond length is 1.77 Å. The Ge(2)-O(6) bond length is 1.80 Å. In the third Ge site, Ge(3) is bonded to one O(1), one O(2), one O(7), and one O(9) atom to form GeO4 tetrahedra that share  a cornercorner with one B(2)O4 tetrahedra,  a cornercorner with one Ge(4)O4 tetrahedra, and corners with two equivalent B(1)O4 tetrahedra. The Ge(3)-O(1) bond length is 1.79 Å. The Ge(3)-O(2) bond length is 1.77 Å. The Ge(3)-O(7) bond length is 1.78 Å. The Ge(3)-O(9) bond length is 1.77 Å. In the fourth Ge site, Ge(4) is bonded to two equivalent O(1) and two equivalent O(8) atoms to form GeO4 tetrahedra that share corners with two equivalent B(1)O4 tetrahedra and corners with two equivalent Ge(3)O4 tetrahedra. Both Ge(4)-O(1) bond lengths are 1.79 Å. Both Ge(4)-O(8) bond lengths are 1.75 Å. There are ten inequivalent O sites. In the first O site, O(5) is bonded in a distorted bent 120 degrees geometry to three equivalent K(2), one B(1), and one Ge(2) atom. In the second O site, O(6) is bonded in a distorted bent 120 degrees geometry to one K(1), one K(2), one Ge(1), and one Ge(2) atom. In the third O site, O(7) is bonded in a distorted bent 120 degrees geometry to two equivalent K(2), one B(1), and one Ge(3) atom. In the fourth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one K(1), one K(2), one B(1), and one Ge(4) atom. In the fifth O site, O(9) is bonded in a 2-coordinate geometry to three equivalent K(1), one B(2), and one Ge(3) atom. In the sixth O site, O(10) is bonded in a bent 120 degrees geometry to one K(1), one B(2), and one Ge(2) atom. In the seventh O site, O(1) is bonded in a 2-coordinate geometry to one K(1), one K(2), one Ge(3), and one Ge(4) atom. In the eighth O site, O(2) is bonded in a distorted bent 120 degrees geometry to one K(1), one B(1), and one Ge(3) atom. In the ninth O site, O(3) is bonded in a distorted bent 120 degrees geometry to one K(1), one B(2), and one Ge(2) atom. In the tenth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one K(1), one K(2), one B(2), and one Ge(1) atom.