Pb2KNb5O15 is Pb(Zr_(1-x)Ti_x)O3-derived structured and crystallizes in the orthorhombic Amm2 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to two equivalent O(5) and four equivalent O(1) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(2), two equivalent O(16), and four equivalent O(11) atoms. There are six inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(14), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 9-38°. In the second Nb site, Nb(2) is bonded to one O(14), one O(15), one O(5), one O(9), and two equivalent O(13) atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 1-43°. In the third Nb site, Nb(3) is bonded in a 6-coordinate geometry to one O(11), one O(15), one O(6), one O(8), and two equivalent O(12) atoms. In the fourth Nb site, Nb(4) is bonded to one O(16), one O(17), one O(4), one O(8), and two equivalent O(10) atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 15-38°. In the fifth Nb site, Nb(5) is bonded to two equivalent O(1), two equivalent O(11), and two equivalent O(2) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 4-22°. In the sixth Nb site, Nb(6) is bonded to one O(1), one O(17), one O(6), one O(9), and two equivalent O(7) atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 1-22°. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 4-coordinate geometry to one O(12), one O(13), and two equivalent O(15) atoms. In the second Pb site, Pb(2) is bonded in a 6-coordinate geometry to one O(10), one O(7), two equivalent O(17), and two equivalent O(4) atoms. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Nb(5), and one Nb(6) atom. In the second O site, O(2) is bonded in a linear geometry to one K(2) and two equivalent Nb(5) atoms. In the third O site, O(3) is bonded in a linear geometry to two equivalent Nb(1) atoms. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Nb(1), one Nb(4), and two equivalent Pb(2) atoms. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent K(1) and two equivalent Nb(2) atoms. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Nb(3) and one Nb(6) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent Nb(6) and one Pb(2) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Nb(3) and one Nb(4) atom. In the ninth O site, O(9) is bonded in a distorted linear geometry to one Nb(2) and one Nb(6) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to two equivalent Nb(4) and one Pb(2) atom. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), one Nb(3), and one Nb(5) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to two equivalent Nb(3) and one Pb(1) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to two equivalent Nb(2) and one Pb(1) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Nb(1) and one Nb(2) atom. In the fifteenth O site, O(15) is bonded in a 4-coordinate geometry to one Nb(2), one Nb(3), and two equivalent Pb(1) atoms. In the sixteenth O site, O(16) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2) and two equivalent Nb(4) atoms. In the seventeenth O site, O(17) is bonded in a 4-coordinate geometry to one Nb(4), one Nb(6), and two equivalent Pb(2) atoms.
Pb2KNb5O15 is Pb(Zr_(1-x)Ti_x)O3-derived structured and crystallizes in the orthorhombic Amm2 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to two equivalent O(5) and four equivalent O(1) atoms. Both K(1)-O(5) bond lengths are 2.90 Å. All K(1)-O(1) bond lengths are 3.10 Å. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(2), two equivalent O(16), and four equivalent O(11) atoms. The K(2)-O(2) bond length is 3.08 Å. Both K(2)-O(16) bond lengths are 3.00 Å. All K(2)-O(11) bond lengths are 2.96 Å. There are six inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(14), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 9-38°. Both Nb(1)-O(14) bond lengths are 2.15 Å. Both Nb(1)-O(3) bond lengths are 1.99 Å. Both Nb(1)-O(4) bond lengths are 1.91 Å. In the second Nb site, Nb(2) is bonded to one O(14), one O(15), one O(5), one O(9), and two equivalent O(13) atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 1-43°. The Nb(2)-O(14) bond length is 1.83 Å. The Nb(2)-O(15) bond length is 2.07 Å. The Nb(2)-O(5) bond length is 1.99 Å. The Nb(2)-O(9) bond length is 2.35 Å. Both Nb(2)-O(13) bond lengths are 2.02 Å. In the third Nb site, Nb(3) is bonded in a 6-coordinate geometry to one O(11), one O(15), one O(6), one O(8), and two equivalent O(12) atoms. The Nb(3)-O(11) bond length is 1.92 Å. The Nb(3)-O(15) bond length is 2.13 Å. The Nb(3)-O(6) bond length is 1.85 Å. The Nb(3)-O(8) bond length is 2.47 Å. Both Nb(3)-O(12) bond lengths are 2.02 Å. In the fourth Nb site, Nb(4) is bonded to one O(16), one O(17), one O(4), one O(8), and two equivalent O(10) atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 15-38°. The Nb(4)-O(16) bond length is 1.98 Å. The Nb(4)-O(17) bond length is 2.10 Å. The Nb(4)-O(4) bond length is 2.23 Å. The Nb(4)-O(8) bond length is 1.86 Å. Both Nb(4)-O(10) bond lengths are 2.00 Å. In the fifth Nb site, Nb(5) is bonded to two equivalent O(1), two equivalent O(11), and two equivalent O(2) atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 4-22°. Both Nb(5)-O(1) bond lengths are 2.00 Å. Both Nb(5)-O(11) bond lengths are 2.05 Å. Both Nb(5)-O(2) bond lengths are 1.98 Å. In the sixth Nb site, Nb(6) is bonded to one O(1), one O(17), one O(6), one O(9), and two equivalent O(7) atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 1-22°. The Nb(6)-O(1) bond length is 1.94 Å. The Nb(6)-O(17) bond length is 2.10 Å. The Nb(6)-O(6) bond length is 2.37 Å. The Nb(6)-O(9) bond length is 1.85 Å. Both Nb(6)-O(7) bond lengths are 2.01 Å. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 4-coordinate geometry to one O(12), one O(13), and two equivalent O(15) atoms. The Pb(1)-O(12) bond length is 2.50 Å. The Pb(1)-O(13) bond length is 2.53 Å. Both Pb(1)-O(15) bond lengths are 2.50 Å. In the second Pb site, Pb(2) is bonded in a 6-coordinate geometry to one O(10), one O(7), two equivalent O(17), and two equivalent O(4) atoms. The Pb(2)-O(10) bond length is 2.61 Å. The Pb(2)-O(7) bond length is 2.63 Å. Both Pb(2)-O(17) bond lengths are 2.64 Å. Both Pb(2)-O(4) bond lengths are 2.63 Å. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Nb(5), and one Nb(6) atom. In the second O site, O(2) is bonded in a linear geometry to one K(2) and two equivalent Nb(5) atoms. In the third O site, O(3) is bonded in a linear geometry to two equivalent Nb(1) atoms. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Nb(1), one Nb(4), and two equivalent Pb(2) atoms. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent K(1) and two equivalent Nb(2) atoms. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Nb(3) and one Nb(6) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent Nb(6) and one Pb(2) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Nb(3) and one Nb(4) atom. In the ninth O site, O(9) is bonded in a distorted linear geometry to one Nb(2) and one Nb(6) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to two equivalent Nb(4) and one Pb(2) atom. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), one Nb(3), and one Nb(5) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to two equivalent Nb(3) and one Pb(1) atom. In the thirteenth O site, O(13) is bonded in a 2-coordinate geometry to two equivalent Nb(2) and one Pb(1) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Nb(1) and one Nb(2) atom. In the fifteenth O site, O(15) is bonded in a 4-coordinate geometry to one Nb(2), one Nb(3), and two equivalent Pb(1) atoms. In the sixteenth O site, O(16) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2) and two equivalent Nb(4) atoms. In the seventeenth O site, O(17) is bonded in a 4-coordinate geometry to one Nb(4), one Nb(6), and two equivalent Pb(2) atoms.