Nb8P5 crystallizes in the orthorhombic Pmc2_1 space group. There are sixteen inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one P(9), two equivalent P(5), and two equivalent P(8) atoms to form a mixture of distorted edge and corner-sharing NbP5 trigonal bipyramids. In the second Nb site, Nb(2) is bonded to one P(10), two equivalent P(6), and two equivalent P(7) atoms to form a mixture of distorted edge and corner-sharing NbP5 trigonal bipyramids. In the third Nb site, Nb(3) is bonded in a 5-coordinate geometry to one P(1), two equivalent P(10), and two equivalent P(3) atoms. In the fourth Nb site, Nb(4) is bonded in a 5-coordinate geometry to one P(2), two equivalent P(4), and two equivalent P(9) atoms. In the fifth Nb site, Nb(5) is bonded to one P(3), two equivalent P(1), and two equivalent P(7) atoms to form a mixture of distorted edge and corner-sharing NbP5 trigonal bipyramids. In the sixth Nb site, Nb(6) is bonded to one P(4), two equivalent P(2), and two equivalent P(8) atoms to form a mixture of distorted edge and corner-sharing NbP5 trigonal bipyramids. In the seventh Nb site, Nb(7) is bonded in a distorted square co-planar geometry to two equivalent P(1) and two equivalent P(5) atoms. In the eighth Nb site, Nb(8) is bonded in a distorted rectangular see-saw-like geometry to two equivalent P(2) and two equivalent P(6) atoms. In the ninth Nb site, Nb(9) is bonded in a distorted rectangular see-saw-like geometry to one P(1), one P(2), one P(5), and one P(6) atom. In the tenth Nb site, Nb(10) is bonded in a 5-coordinate geometry to one P(3), one P(4), one P(9), and two equivalent P(7) atoms. In the eleventh Nb site, Nb(11) is bonded in a 5-coordinate geometry to one P(10), one P(3), one P(4), and two equivalent P(8) atoms. In the twelfth Nb site, Nb(12) is bonded in a 5-coordinate geometry to one P(9), two equivalent P(2), and two equivalent P(5) atoms. In the thirteenth Nb site, Nb(13) is bonded in a 5-coordinate geometry to one P(10), two equivalent P(1), and two equivalent P(6) atoms. In the fourteenth Nb site, Nb(14) is bonded in a 5-coordinate geometry to one P(8), two equivalent P(3), and two equivalent P(9) atoms. In the fifteenth Nb site, Nb(15) is bonded in a 5-coordinate geometry to one P(7), two equivalent P(10), and two equivalent P(4) atoms. In the sixteenth Nb site, Nb(16) is bonded in a 3-coordinate geometry to one P(2), one P(5), and one P(8) atom. There are ten inequivalent P sites. In the first P site, P(1) is bonded in a 8-coordinate geometry to one Nb(3), one Nb(9), two equivalent Nb(13), two equivalent Nb(5), and two equivalent Nb(7) atoms. In the second P site, P(2) is bonded in a 9-coordinate geometry to one Nb(16), one Nb(4), one Nb(9), two equivalent Nb(12), two equivalent Nb(6), and two equivalent Nb(8) atoms. In the third P site, P(3) is bonded in a 7-coordinate geometry to one Nb(10), one Nb(11), one Nb(5), two equivalent Nb(14), and two equivalent Nb(3) atoms. In the fourth P site, P(4) is bonded in a 7-coordinate geometry to one Nb(10), one Nb(11), one Nb(6), two equivalent Nb(15), and two equivalent Nb(4) atoms. In the fifth P site, P(5) is bonded in a 8-coordinate geometry to one Nb(16), one Nb(9), two equivalent Nb(1), two equivalent Nb(12), and two equivalent Nb(7) atoms. In the sixth P site, P(6) is bonded to one Nb(9), two equivalent Nb(13), two equivalent Nb(2), and two equivalent Nb(8) atoms to form distorted face-sharing PNb7 pentagonal bipyramids. In the seventh P site, P(7) is bonded in a 7-coordinate geometry to one Nb(15), two equivalent Nb(10), two equivalent Nb(2), and two equivalent Nb(5) atoms. In the eighth P site, P(8) is bonded in a 8-coordinate geometry to one Nb(14), one Nb(16), two equivalent Nb(1), two equivalent Nb(11), and two equivalent Nb(6) atoms. In the ninth P site, P(9) is bonded to one Nb(1), one Nb(10), one Nb(12), two equivalent Nb(14), and two equivalent Nb(4) atoms to form distorted edge-sharing PNb7 pentagonal bipyramids. In the tenth P site, P(10) is bonded in a 7-coordinate geometry to one Nb(11), one Nb(13), one Nb(2), two equivalent Nb(15), and two equivalent Nb(3) atoms.
Nb8P5 crystallizes in the orthorhombic Pmc2_1 space group. There are sixteen inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one P(9), two equivalent P(5), and two equivalent P(8) atoms to form a mixture of distorted edge and corner-sharing NbP5 trigonal bipyramids. The Nb(1)-P(9) bond length is 2.51 Å. Both Nb(1)-P(5) bond lengths are 2.57 Å. Both Nb(1)-P(8) bond lengths are 2.55 Å. In the second Nb site, Nb(2) is bonded to one P(10), two equivalent P(6), and two equivalent P(7) atoms to form a mixture of distorted edge and corner-sharing NbP5 trigonal bipyramids. The Nb(2)-P(10) bond length is 2.44 Å. Both Nb(2)-P(6) bond lengths are 2.56 Å. Both Nb(2)-P(7) bond lengths are 2.53 Å. In the third Nb site, Nb(3) is bonded in a 5-coordinate geometry to one P(1), two equivalent P(10), and two equivalent P(3) atoms. The Nb(3)-P(1) bond length is 2.95 Å. Both Nb(3)-P(10) bond lengths are 2.53 Å. Both Nb(3)-P(3) bond lengths are 2.50 Å. In the fourth Nb site, Nb(4) is bonded in a 5-coordinate geometry to one P(2), two equivalent P(4), and two equivalent P(9) atoms. The Nb(4)-P(2) bond length is 2.90 Å. Both Nb(4)-P(4) bond lengths are 2.50 Å. Both Nb(4)-P(9) bond lengths are 2.52 Å. In the fifth Nb site, Nb(5) is bonded to one P(3), two equivalent P(1), and two equivalent P(7) atoms to form a mixture of distorted edge and corner-sharing NbP5 trigonal bipyramids. The Nb(5)-P(3) bond length is 2.45 Å. Both Nb(5)-P(1) bond lengths are 2.52 Å. Both Nb(5)-P(7) bond lengths are 2.60 Å. In the sixth Nb site, Nb(6) is bonded to one P(4), two equivalent P(2), and two equivalent P(8) atoms to form a mixture of distorted edge and corner-sharing NbP5 trigonal bipyramids. The Nb(6)-P(4) bond length is 2.53 Å. Both Nb(6)-P(2) bond lengths are 2.54 Å. Both Nb(6)-P(8) bond lengths are 2.59 Å. In the seventh Nb site, Nb(7) is bonded in a distorted square co-planar geometry to two equivalent P(1) and two equivalent P(5) atoms. Both Nb(7)-P(1) bond lengths are 2.64 Å. Both Nb(7)-P(5) bond lengths are 2.54 Å. In the eighth Nb site, Nb(8) is bonded in a distorted rectangular see-saw-like geometry to two equivalent P(2) and two equivalent P(6) atoms. Both Nb(8)-P(2) bond lengths are 2.59 Å. Both Nb(8)-P(6) bond lengths are 2.59 Å. In the ninth Nb site, Nb(9) is bonded in a distorted rectangular see-saw-like geometry to one P(1), one P(2), one P(5), and one P(6) atom. The Nb(9)-P(1) bond length is 2.71 Å. The Nb(9)-P(2) bond length is 2.72 Å. The Nb(9)-P(5) bond length is 2.64 Å. The Nb(9)-P(6) bond length is 2.64 Å. In the tenth Nb site, Nb(10) is bonded in a 5-coordinate geometry to one P(3), one P(4), one P(9), and two equivalent P(7) atoms. The Nb(10)-P(3) bond length is 2.47 Å. The Nb(10)-P(4) bond length is 2.68 Å. The Nb(10)-P(9) bond length is 2.70 Å. Both Nb(10)-P(7) bond lengths are 2.64 Å. In the eleventh Nb site, Nb(11) is bonded in a 5-coordinate geometry to one P(10), one P(3), one P(4), and two equivalent P(8) atoms. The Nb(11)-P(10) bond length is 2.74 Å. The Nb(11)-P(3) bond length is 2.69 Å. The Nb(11)-P(4) bond length is 2.47 Å. Both Nb(11)-P(8) bond lengths are 2.59 Å. In the twelfth Nb site, Nb(12) is bonded in a 5-coordinate geometry to one P(9), two equivalent P(2), and two equivalent P(5) atoms. The Nb(12)-P(9) bond length is 2.50 Å. Both Nb(12)-P(2) bond lengths are 2.59 Å. Both Nb(12)-P(5) bond lengths are 2.64 Å. In the thirteenth Nb site, Nb(13) is bonded in a 5-coordinate geometry to one P(10), two equivalent P(1), and two equivalent P(6) atoms. The Nb(13)-P(10) bond length is 2.50 Å. Both Nb(13)-P(1) bond lengths are 2.61 Å. Both Nb(13)-P(6) bond lengths are 2.69 Å. In the fourteenth Nb site, Nb(14) is bonded in a 5-coordinate geometry to one P(8), two equivalent P(3), and two equivalent P(9) atoms. The Nb(14)-P(8) bond length is 2.72 Å. Both Nb(14)-P(3) bond lengths are 2.53 Å. Both Nb(14)-P(9) bond lengths are 2.52 Å. In the fifteenth Nb site, Nb(15) is bonded in a 5-coordinate geometry to one P(7), two equivalent P(10), and two equivalent P(4) atoms. The Nb(15)-P(7) bond length is 2.74 Å. Both Nb(15)-P(10) bond lengths are 2.51 Å. Both Nb(15)-P(4) bond lengths are 2.53 Å. In the sixteenth Nb site, Nb(16) is bonded in a 3-coordinate geometry to one P(2), one P(5), and one P(8) atom. The Nb(16)-P(2) bond length is 2.87 Å. The Nb(16)-P(5) bond length is 2.79 Å. The Nb(16)-P(8) bond length is 2.94 Å. There are ten inequivalent P sites. In the first P site, P(1) is bonded in a 8-coordinate geometry to one Nb(3), one Nb(9), two equivalent Nb(13), two equivalent Nb(5), and two equivalent Nb(7) atoms. In the second P site, P(2) is bonded in a 9-coordinate geometry to one Nb(16), one Nb(4), one Nb(9), two equivalent Nb(12), two equivalent Nb(6), and two equivalent Nb(8) atoms. In the third P site, P(3) is bonded in a 7-coordinate geometry to one Nb(10), one Nb(11), one Nb(5), two equivalent Nb(14), and two equivalent Nb(3) atoms. In the fourth P site, P(4) is bonded in a 7-coordinate geometry to one Nb(10), one Nb(11), one Nb(6), two equivalent Nb(15), and two equivalent Nb(4) atoms. In the fifth P site, P(5) is bonded in a 8-coordinate geometry to one Nb(16), one Nb(9), two equivalent Nb(1), two equivalent Nb(12), and two equivalent Nb(7) atoms. In the sixth P site, P(6) is bonded to one Nb(9), two equivalent Nb(13), two equivalent Nb(2), and two equivalent Nb(8) atoms to form distorted face-sharing PNb7 pentagonal bipyramids. In the seventh P site, P(7) is bonded in a 7-coordinate geometry to one Nb(15), two equivalent Nb(10), two equivalent Nb(2), and two equivalent Nb(5) atoms. In the eighth P site, P(8) is bonded in a 8-coordinate geometry to one Nb(14), one Nb(16), two equivalent Nb(1), two equivalent Nb(11), and two equivalent Nb(6) atoms. In the ninth P site, P(9) is bonded to one Nb(1), one Nb(10), one Nb(12), two equivalent Nb(14), and two equivalent Nb(4) atoms to form distorted edge-sharing PNb7 pentagonal bipyramids. In the tenth P site, P(10) is bonded in a 7-coordinate geometry to one Nb(11), one Nb(13), one Nb(2), two equivalent Nb(15), and two equivalent Nb(3) atoms.