RbNb2PS10 crystallizes in the monoclinic Pc space group. Rb(1) is bonded in a 5-coordinate geometry to one S(2), one S(5), one S(6), and two equivalent S(1) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one S(10), one S(3), one S(4), one S(5), one S(6), one S(7), one S(8), and one S(9) atom to form distorted NbS8 hexagonal bipyramids that share  an edgeedge with one P(1)S4 tetrahedra and faces with two equivalent Nb(2)S8 hexagonal bipyramids. In the second Nb site, Nb(2) is bonded to one S(10), one S(2), one S(3), one S(4), one S(5), one S(6), one S(7), and one S(8) atom to form NbS8 hexagonal bipyramids that share  an edgeedge with one P(1)S4 tetrahedra and faces with two equivalent Nb(1)S8 hexagonal bipyramids. P(1) is bonded to one S(1), one S(10), one S(2), and one S(9) atom to form PS4 tetrahedra that share  an edgeedge with one Nb(1)S8 hexagonal bipyramid and  an edgeedge with one Nb(2)S8 hexagonal bipyramid. There are ten inequivalent S sites. In the first S site, S(1) is bonded in a 3-coordinate geometry to two equivalent Rb(1) and one P(1) atom. In the second S site, S(2) is bonded in a distorted trigonal non-coplanar geometry to one Rb(1), one Nb(2), and one P(1) atom. In the third S site, S(3) is bonded in a 3-coordinate geometry to one Nb(1), one Nb(2), and one S(4) atom. In the fourth S site, S(4) is bonded in a 3-coordinate geometry to one Nb(1), one Nb(2), and one S(3) atom. In the fifth S site, S(5) is bonded in a 4-coordinate geometry to one Rb(1), one Nb(1), one Nb(2), and one S(6) atom. In the sixth S site, S(6) is bonded in a 4-coordinate geometry to one Rb(1), one Nb(1), one Nb(2), and one S(5) atom. In the seventh S site, S(7) is bonded in a 3-coordinate geometry to one Nb(1), one Nb(2), and one S(8) atom. In the eighth S site, S(8) is bonded in a 3-coordinate geometry to one Nb(1), one Nb(2), and one S(7) atom. In the ninth S site, S(9) is bonded in a distorted L-shaped geometry to one Nb(1) and one P(1) atom. In the tenth S site, S(10) is bonded in a distorted T-shaped geometry to one Nb(1), one Nb(2), and one P(1) atom.
RbNb2PS10 crystallizes in the monoclinic Pc space group. Rb(1) is bonded in a 5-coordinate geometry to one S(2), one S(5), one S(6), and two equivalent S(1) atoms. The Rb(1)-S(2) bond length is 3.58 Å. The Rb(1)-S(5) bond length is 3.70 Å. The Rb(1)-S(6) bond length is 3.68 Å. There is one shorter (3.51 Å) and one longer (3.72 Å) Rb(1)-S(1) bond length. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one S(10), one S(3), one S(4), one S(5), one S(6), one S(7), one S(8), and one S(9) atom to form distorted NbS8 hexagonal bipyramids that share  an edgeedge with one P(1)S4 tetrahedra and faces with two equivalent Nb(2)S8 hexagonal bipyramids. The Nb(1)-S(10) bond length is 2.66 Å. The Nb(1)-S(3) bond length is 2.49 Å. The Nb(1)-S(4) bond length is 2.54 Å. The Nb(1)-S(5) bond length is 2.56 Å. The Nb(1)-S(6) bond length is 2.51 Å. The Nb(1)-S(7) bond length is 2.59 Å. The Nb(1)-S(8) bond length is 2.57 Å. The Nb(1)-S(9) bond length is 2.59 Å. In the second Nb site, Nb(2) is bonded to one S(10), one S(2), one S(3), one S(4), one S(5), one S(6), one S(7), and one S(8) atom to form NbS8 hexagonal bipyramids that share  an edgeedge with one P(1)S4 tetrahedra and faces with two equivalent Nb(1)S8 hexagonal bipyramids. The Nb(2)-S(10) bond length is 2.66 Å. The Nb(2)-S(2) bond length is 2.60 Å. The Nb(2)-S(3) bond length is 2.53 Å. The Nb(2)-S(4) bond length is 2.50 Å. The Nb(2)-S(5) bond length is 2.51 Å. The Nb(2)-S(6) bond length is 2.56 Å. The Nb(2)-S(7) bond length is 2.59 Å. The Nb(2)-S(8) bond length is 2.58 Å. P(1) is bonded to one S(1), one S(10), one S(2), and one S(9) atom to form PS4 tetrahedra that share  an edgeedge with one Nb(1)S8 hexagonal bipyramid and  an edgeedge with one Nb(2)S8 hexagonal bipyramid. The P(1)-S(1) bond length is 1.98 Å. The P(1)-S(10) bond length is 2.11 Å. The P(1)-S(2) bond length is 2.07 Å. The P(1)-S(9) bond length is 2.06 Å. There are ten inequivalent S sites. In the first S site, S(1) is bonded in a 3-coordinate geometry to two equivalent Rb(1) and one P(1) atom. In the second S site, S(2) is bonded in a distorted trigonal non-coplanar geometry to one Rb(1), one Nb(2), and one P(1) atom. In the third S site, S(3) is bonded in a 3-coordinate geometry to one Nb(1), one Nb(2), and one S(4) atom. The S(3)-S(4) bond length is 2.03 Å. In the fourth S site, S(4) is bonded in a 3-coordinate geometry to one Nb(1), one Nb(2), and one S(3) atom. In the fifth S site, S(5) is bonded in a 4-coordinate geometry to one Rb(1), one Nb(1), one Nb(2), and one S(6) atom. The S(5)-S(6) bond length is 2.04 Å. In the sixth S site, S(6) is bonded in a 4-coordinate geometry to one Rb(1), one Nb(1), one Nb(2), and one S(5) atom. In the seventh S site, S(7) is bonded in a 3-coordinate geometry to one Nb(1), one Nb(2), and one S(8) atom. The S(7)-S(8) bond length is 2.05 Å. In the eighth S site, S(8) is bonded in a 3-coordinate geometry to one Nb(1), one Nb(2), and one S(7) atom. In the ninth S site, S(9) is bonded in a distorted L-shaped geometry to one Nb(1) and one P(1) atom. In the tenth S site, S(10) is bonded in a distorted T-shaped geometry to one Nb(1), one Nb(2), and one P(1) atom.