K3Li2Nb5O15 crystallizes in the tetragonal P4/mbm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to four equivalent O(5) and eight equivalent O(4) atoms to form KO12 cuboctahedra that share faces with two equivalent K(1)O12 cuboctahedra and faces with eight equivalent Nb(2)O6 octahedra. In the second K site, K(2) is bonded in a 9-coordinate geometry to one O(2), two equivalent O(3), two equivalent O(5), and four equivalent O(1) atoms. Li(1) is bonded in a distorted trigonal planar geometry to one O(2), two equivalent O(3), two equivalent O(5), and four equivalent O(1) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 0-27°. In the second Nb site, Nb(2) is bonded to one O(1), one O(3), two equivalent O(4), and two equivalent O(5) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra, corners with five equivalent Nb(2)O6 octahedra, and faces with two equivalent K(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-27°. There are five inequivalent O sites. In the first O site, O(4) is bonded in a distorted linear geometry to two equivalent K(1) and two equivalent Nb(2) atoms. In the second O site, O(5) is bonded in a distorted T-shaped geometry to one K(1), one K(2), one Li(1), and two equivalent Nb(2) atoms. In the third O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), two equivalent Li(1), one Nb(1), and one Nb(2) atom. In the fourth O site, O(2) is bonded in a square co-planar geometry to two equivalent K(2), two equivalent Li(1), and two equivalent Nb(1) atoms. In the fifth O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), two equivalent Li(1), and two equivalent Nb(2) atoms.
K3Li2Nb5O15 crystallizes in the tetragonal P4/mbm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to four equivalent O(5) and eight equivalent O(4) atoms to form KO12 cuboctahedra that share faces with two equivalent K(1)O12 cuboctahedra and faces with eight equivalent Nb(2)O6 octahedra. All K(1)-O(5) bond lengths are 2.95 Å. All K(1)-O(4) bond lengths are 2.85 Å. In the second K site, K(2) is bonded in a 9-coordinate geometry to one O(2), two equivalent O(3), two equivalent O(5), and four equivalent O(1) atoms. The K(2)-O(2) bond length is 3.14 Å. Both K(2)-O(3) bond lengths are 2.94 Å. Both K(2)-O(5) bond lengths are 3.25 Å. All K(2)-O(1) bond lengths are 3.03 Å. Li(1) is bonded in a distorted trigonal planar geometry to one O(2), two equivalent O(3), two equivalent O(5), and four equivalent O(1) atoms. The Li(1)-O(2) bond length is 2.23 Å. Both Li(1)-O(3) bond lengths are 2.57 Å. Both Li(1)-O(5) bond lengths are 2.16 Å. All Li(1)-O(1) bond lengths are 2.57 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 0-27°. Both Nb(1)-O(2) bond lengths are 2.02 Å. All Nb(1)-O(1) bond lengths are 1.99 Å. In the second Nb site, Nb(2) is bonded to one O(1), one O(3), two equivalent O(4), and two equivalent O(5) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra, corners with five equivalent Nb(2)O6 octahedra, and faces with two equivalent K(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-27°. The Nb(2)-O(1) bond length is 2.01 Å. The Nb(2)-O(3) bond length is 2.03 Å. There is one shorter (1.97 Å) and one longer (2.04 Å) Nb(2)-O(4) bond length. Both Nb(2)-O(5) bond lengths are 2.02 Å. There are five inequivalent O sites. In the first O site, O(4) is bonded in a distorted linear geometry to two equivalent K(1) and two equivalent Nb(2) atoms. In the second O site, O(5) is bonded in a distorted T-shaped geometry to one K(1), one K(2), one Li(1), and two equivalent Nb(2) atoms. In the third O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), two equivalent Li(1), one Nb(1), and one Nb(2) atom. In the fourth O site, O(2) is bonded in a square co-planar geometry to two equivalent K(2), two equivalent Li(1), and two equivalent Nb(1) atoms. In the fifth O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), two equivalent Li(1), and two equivalent Nb(2) atoms.