Rb3Nb2AsSe11 crystallizes in the monoclinic Cc space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 7-coordinate geometry to one Se(1), one Se(10), one Se(11), one Se(8), one Se(9), and two equivalent Se(4) atoms. In the second Rb site, Rb(2) is bonded in a 9-coordinate geometry to one As(1), one Se(2), one Se(3), one Se(5), one Se(9), two equivalent Se(10), and two equivalent Se(7) atoms. In the third Rb site, Rb(3) is bonded in a 9-coordinate geometry to one Se(1), one Se(11), one Se(2), one Se(5), one Se(8), two equivalent Se(7), and two equivalent Se(9) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 7-coordinate geometry to one Se(11), one Se(2), one Se(3), one Se(4), one Se(5), one Se(7), and one Se(8) atom. In the second Nb site, Nb(2) is bonded in a distorted pentagonal bipyramidal geometry to one Se(1), one Se(10), one Se(11), one Se(3), one Se(5), one Se(6), and one Se(9) atom. As(1) is bonded in a 3-coordinate geometry to one Rb(2), one Se(10), one Se(4), and one Se(6) atom. There are eleven inequivalent Se sites. In the first Se site, Se(7) is bonded in a 5-coordinate geometry to two equivalent Rb(2), two equivalent Rb(3), and one Nb(1) atom. In the second Se site, Se(8) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(3), one Nb(1), and one Se(5) atom. In the third Se site, Se(9) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), two equivalent Rb(3), and one Nb(2) atom. In the fourth Se site, Se(10) is bonded in a distorted L-shaped geometry to one Rb(1), two equivalent Rb(2), one Nb(2), and one As(1) atom. In the fifth Se site, Se(11) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(3), one Nb(1), one Nb(2), and one Se(1) atom. In the sixth Se site, Se(1) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(3), one Nb(2), and one Se(11) atom. In the seventh Se site, Se(2) is bonded in a 4-coordinate geometry to one Rb(2), one Rb(3), one Nb(1), and one Se(3) atom. In the eighth Se site, Se(3) is bonded in a 2-coordinate geometry to one Rb(2), one Nb(1), one Nb(2), and one Se(2) atom. In the ninth Se site, Se(4) is bonded in a 4-coordinate geometry to two equivalent Rb(1), one Nb(1), and one As(1) atom. In the tenth Se site, Se(5) is bonded in a 2-coordinate geometry to one Rb(2), one Rb(3), one Nb(1), one Nb(2), and one Se(8) atom. In the eleventh Se site, Se(6) is bonded in an L-shaped geometry to one Nb(2) and one As(1) atom.
Rb3Nb2AsSe11 crystallizes in the monoclinic Cc space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 7-coordinate geometry to one Se(1), one Se(10), one Se(11), one Se(8), one Se(9), and two equivalent Se(4) atoms. The Rb(1)-Se(1) bond length is 3.72 Å. The Rb(1)-Se(10) bond length is 3.90 Å. The Rb(1)-Se(11) bond length is 3.87 Å. The Rb(1)-Se(8) bond length is 3.77 Å. The Rb(1)-Se(9) bond length is 3.77 Å. There is one shorter (3.56 Å) and one longer (3.73 Å) Rb(1)-Se(4) bond length. In the second Rb site, Rb(2) is bonded in a 9-coordinate geometry to one As(1), one Se(2), one Se(3), one Se(5), one Se(9), two equivalent Se(10), and two equivalent Se(7) atoms. The Rb(2)-As(1) bond length is 3.71 Å. The Rb(2)-Se(2) bond length is 3.48 Å. The Rb(2)-Se(3) bond length is 3.95 Å. The Rb(2)-Se(5) bond length is 4.09 Å. The Rb(2)-Se(9) bond length is 3.59 Å. There is one shorter (3.90 Å) and one longer (3.94 Å) Rb(2)-Se(10) bond length. There is one shorter (3.43 Å) and one longer (3.68 Å) Rb(2)-Se(7) bond length. In the third Rb site, Rb(3) is bonded in a 9-coordinate geometry to one Se(1), one Se(11), one Se(2), one Se(5), one Se(8), two equivalent Se(7), and two equivalent Se(9) atoms. The Rb(3)-Se(1) bond length is 3.51 Å. The Rb(3)-Se(11) bond length is 3.70 Å. The Rb(3)-Se(2) bond length is 3.63 Å. The Rb(3)-Se(5) bond length is 3.73 Å. The Rb(3)-Se(8) bond length is 3.65 Å. There is one shorter (3.55 Å) and one longer (3.69 Å) Rb(3)-Se(7) bond length. There is one shorter (3.73 Å) and one longer (3.76 Å) Rb(3)-Se(9) bond length. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 7-coordinate geometry to one Se(11), one Se(2), one Se(3), one Se(4), one Se(5), one Se(7), and one Se(8) atom. The Nb(1)-Se(11) bond length is 2.91 Å. The Nb(1)-Se(2) bond length is 2.64 Å. The Nb(1)-Se(3) bond length is 2.68 Å. The Nb(1)-Se(4) bond length is 2.68 Å. The Nb(1)-Se(5) bond length is 2.64 Å. The Nb(1)-Se(7) bond length is 2.38 Å. The Nb(1)-Se(8) bond length is 2.60 Å. In the second Nb site, Nb(2) is bonded in a distorted pentagonal bipyramidal geometry to one Se(1), one Se(10), one Se(11), one Se(3), one Se(5), one Se(6), and one Se(9) atom. The Nb(2)-Se(1) bond length is 2.61 Å. The Nb(2)-Se(10) bond length is 2.73 Å. The Nb(2)-Se(11) bond length is 2.62 Å. The Nb(2)-Se(3) bond length is 2.76 Å. The Nb(2)-Se(5) bond length is 2.97 Å. The Nb(2)-Se(6) bond length is 2.65 Å. The Nb(2)-Se(9) bond length is 2.37 Å. As(1) is bonded in a 3-coordinate geometry to one Rb(2), one Se(10), one Se(4), and one Se(6) atom. The As(1)-Se(10) bond length is 2.47 Å. The As(1)-Se(4) bond length is 2.42 Å. The As(1)-Se(6) bond length is 2.41 Å. There are eleven inequivalent Se sites. In the first Se site, Se(7) is bonded in a 5-coordinate geometry to two equivalent Rb(2), two equivalent Rb(3), and one Nb(1) atom. In the second Se site, Se(8) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(3), one Nb(1), and one Se(5) atom. The Se(8)-Se(5) bond length is 2.41 Å. In the third Se site, Se(9) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), two equivalent Rb(3), and one Nb(2) atom. In the fourth Se site, Se(10) is bonded in a distorted L-shaped geometry to one Rb(1), two equivalent Rb(2), one Nb(2), and one As(1) atom. In the fifth Se site, Se(11) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(3), one Nb(1), one Nb(2), and one Se(1) atom. The Se(11)-Se(1) bond length is 2.39 Å. In the sixth Se site, Se(1) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(3), one Nb(2), and one Se(11) atom. In the seventh Se site, Se(2) is bonded in a 4-coordinate geometry to one Rb(2), one Rb(3), one Nb(1), and one Se(3) atom. The Se(2)-Se(3) bond length is 2.39 Å. In the eighth Se site, Se(3) is bonded in a 2-coordinate geometry to one Rb(2), one Nb(1), one Nb(2), and one Se(2) atom. In the ninth Se site, Se(4) is bonded in a 4-coordinate geometry to two equivalent Rb(1), one Nb(1), and one As(1) atom. In the tenth Se site, Se(5) is bonded in a 2-coordinate geometry to one Rb(2), one Rb(3), one Nb(1), one Nb(2), and one Se(8) atom. In the eleventh Se site, Se(6) is bonded in an L-shaped geometry to one Nb(2) and one As(1) atom.