BaYbAl2Si2N5O2 crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one Si(1), one N(1), one N(2), one N(4), one N(9), one O(1), one O(2), one O(3), and one O(4) atom. In the second Ba site, Ba(2) is bonded in a 2-coordinate geometry to one N(9), one O(1), and one O(3) atom. There are two inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 5-coordinate geometry to one N(1), one N(7), one N(9), one O(2), and one O(4) atom. In the second Yb site, Yb(2) is bonded in a 6-coordinate geometry to one N(2), one N(5), one N(8), one O(1), one O(3), and one O(4) atom. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted rectangular see-saw-like geometry to one N(2), one N(5), one N(6), and one O(2) atom. In the second Al site, Al(2) is bonded to one N(10), one N(5), one O(1), and one O(3) atom to form distorted AlN2O2 tetrahedra that share  a cornercorner with one Si(3)N4 tetrahedra and  a cornercorner with one Si(4)N4 tetrahedra. In the third Al site, Al(3) is bonded in a 5-coordinate geometry to one N(2), one N(6), one N(7), one O(2), and one O(3) atom. In the fourth Al site, Al(4) is bonded to one N(1), one N(7), one N(9), and one O(4) atom to form distorted AlN3O tetrahedra that share  a cornercorner with one Si(3)N4 tetrahedra and  a cornercorner with one Si(4)N4 tetrahedra. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in an L-shaped geometry to one Ba(1), one N(3), and one N(8) atom. In the second Si site, Si(2) is bonded in a 3-coordinate geometry to one N(1), one N(4), and one N(8) atom. In the third Si site, Si(3) is bonded to one N(10), one N(4), one N(8), and one N(9) atom to form SiN4 tetrahedra that share  a cornercorner with one Al(2)N2O2 tetrahedra and  a cornercorner with one Al(4)N3O tetrahedra. In the fourth Si site, Si(4) is bonded to one N(1), one N(2), one N(3), and one N(5) atom to form SiN4 tetrahedra that share  a cornercorner with one Al(2)N2O2 tetrahedra and  a cornercorner with one Al(4)N3O tetrahedra. There are ten inequivalent N sites. In the first N site, N(1) is bonded in a 5-coordinate geometry to one Ba(1), one Yb(1), one Al(4), one Si(2), and one Si(4) atom. In the second N site, N(2) is bonded in a 5-coordinate geometry to one Ba(1), one Yb(2), one Al(1), one Al(3), and one Si(4) atom. In the third N site, N(3) is bonded in a distorted trigonal planar geometry to one Si(1), one Si(4), and one N(4) atom. In the fourth N site, N(4) is bonded in a 4-coordinate geometry to one Ba(1), one Si(2), one Si(3), and one N(3) atom. In the fifth N site, N(5) is bonded in a 3-coordinate geometry to one Yb(2), one Al(1), one Al(2), and one Si(4) atom. In the sixth N site, N(6) is bonded in a 4-coordinate geometry to one Al(1), one Al(3), one N(10), and one N(7) atom. In the seventh N site, N(7) is bonded in a 4-coordinate geometry to one Yb(1), one Al(3), one Al(4), and one N(6) atom. In the eighth N site, N(8) is bonded in a 4-coordinate geometry to one Yb(2), one Si(1), one Si(2), and one Si(3) atom. In the ninth N site, N(9) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one Yb(1), one Al(4), and one Si(3) atom. In the tenth N site, N(10) is bonded in a 2-coordinate geometry to one Al(2), one Si(3), and one N(6) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), one Ba(2), one Yb(2), and one Al(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ba(1), one Yb(1), one Al(1), and one Al(3) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one Yb(2), one Al(2), and one Al(3) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ba(1), one Yb(1), one Yb(2), and one Al(4) atom.
BaYbAl2Si2N5O2 crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one Si(1), one N(1), one N(2), one N(4), one N(9), one O(1), one O(2), one O(3), and one O(4) atom. The Ba(1)-Si(1) bond length is 3.19 Å. The Ba(1)-N(1) bond length is 2.84 Å. The Ba(1)-N(2) bond length is 2.94 Å. The Ba(1)-N(4) bond length is 3.02 Å. The Ba(1)-N(9) bond length is 2.94 Å. The Ba(1)-O(1) bond length is 2.57 Å. The Ba(1)-O(2) bond length is 3.28 Å. The Ba(1)-O(3) bond length is 2.81 Å. The Ba(1)-O(4) bond length is 2.61 Å. In the second Ba site, Ba(2) is bonded in a 2-coordinate geometry to one N(9), one O(1), and one O(3) atom. The Ba(2)-N(9) bond length is 2.84 Å. The Ba(2)-O(1) bond length is 2.56 Å. The Ba(2)-O(3) bond length is 2.65 Å. There are two inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 5-coordinate geometry to one N(1), one N(7), one N(9), one O(2), and one O(4) atom. The Yb(1)-N(1) bond length is 2.52 Å. The Yb(1)-N(7) bond length is 2.33 Å. The Yb(1)-N(9) bond length is 2.36 Å. The Yb(1)-O(2) bond length is 2.44 Å. The Yb(1)-O(4) bond length is 2.57 Å. In the second Yb site, Yb(2) is bonded in a 6-coordinate geometry to one N(2), one N(5), one N(8), one O(1), one O(3), and one O(4) atom. The Yb(2)-N(2) bond length is 2.57 Å. The Yb(2)-N(5) bond length is 2.66 Å. The Yb(2)-N(8) bond length is 2.65 Å. The Yb(2)-O(1) bond length is 2.40 Å. The Yb(2)-O(3) bond length is 2.40 Å. The Yb(2)-O(4) bond length is 2.43 Å. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted rectangular see-saw-like geometry to one N(2), one N(5), one N(6), and one O(2) atom. The Al(1)-N(2) bond length is 2.08 Å. The Al(1)-N(5) bond length is 1.94 Å. The Al(1)-N(6) bond length is 1.88 Å. The Al(1)-O(2) bond length is 1.78 Å. In the second Al site, Al(2) is bonded to one N(10), one N(5), one O(1), and one O(3) atom to form distorted AlN2O2 tetrahedra that share  a cornercorner with one Si(3)N4 tetrahedra and  a cornercorner with one Si(4)N4 tetrahedra. The Al(2)-N(10) bond length is 1.98 Å. The Al(2)-N(5) bond length is 1.94 Å. The Al(2)-O(1) bond length is 1.78 Å. The Al(2)-O(3) bond length is 1.88 Å. In the third Al site, Al(3) is bonded in a 5-coordinate geometry to one N(2), one N(6), one N(7), one O(2), and one O(3) atom. The Al(3)-N(2) bond length is 1.97 Å. The Al(3)-N(6) bond length is 2.01 Å. The Al(3)-N(7) bond length is 1.98 Å. The Al(3)-O(2) bond length is 1.85 Å. The Al(3)-O(3) bond length is 1.89 Å. In the fourth Al site, Al(4) is bonded to one N(1), one N(7), one N(9), and one O(4) atom to form distorted AlN3O tetrahedra that share  a cornercorner with one Si(3)N4 tetrahedra and  a cornercorner with one Si(4)N4 tetrahedra. The Al(4)-N(1) bond length is 1.95 Å. The Al(4)-N(7) bond length is 1.94 Å. The Al(4)-N(9) bond length is 1.91 Å. The Al(4)-O(4) bond length is 1.76 Å. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in an L-shaped geometry to one Ba(1), one N(3), and one N(8) atom. The Si(1)-N(3) bond length is 1.69 Å. The Si(1)-N(8) bond length is 1.78 Å. In the second Si site, Si(2) is bonded in a 3-coordinate geometry to one N(1), one N(4), and one N(8) atom. The Si(2)-N(1) bond length is 1.80 Å. The Si(2)-N(4) bond length is 1.90 Å. The Si(2)-N(8) bond length is 1.93 Å. In the third Si site, Si(3) is bonded to one N(10), one N(4), one N(8), and one N(9) atom to form SiN4 tetrahedra that share  a cornercorner with one Al(2)N2O2 tetrahedra and  a cornercorner with one Al(4)N3O tetrahedra. The Si(3)-N(10) bond length is 1.77 Å. The Si(3)-N(4) bond length is 1.80 Å. The Si(3)-N(8) bond length is 1.87 Å. The Si(3)-N(9) bond length is 1.69 Å. In the fourth Si site, Si(4) is bonded to one N(1), one N(2), one N(3), and one N(5) atom to form SiN4 tetrahedra that share  a cornercorner with one Al(2)N2O2 tetrahedra and  a cornercorner with one Al(4)N3O tetrahedra. The Si(4)-N(1) bond length is 1.78 Å. The Si(4)-N(2) bond length is 1.74 Å. The Si(4)-N(3) bond length is 1.73 Å. The Si(4)-N(5) bond length is 1.77 Å. There are ten inequivalent N sites. In the first N site, N(1) is bonded in a 5-coordinate geometry to one Ba(1), one Yb(1), one Al(4), one Si(2), and one Si(4) atom. In the second N site, N(2) is bonded in a 5-coordinate geometry to one Ba(1), one Yb(2), one Al(1), one Al(3), and one Si(4) atom. In the third N site, N(3) is bonded in a distorted trigonal planar geometry to one Si(1), one Si(4), and one N(4) atom. The N(3)-N(4) bond length is 1.44 Å. In the fourth N site, N(4) is bonded in a 4-coordinate geometry to one Ba(1), one Si(2), one Si(3), and one N(3) atom. In the fifth N site, N(5) is bonded in a 3-coordinate geometry to one Yb(2), one Al(1), one Al(2), and one Si(4) atom. In the sixth N site, N(6) is bonded in a 4-coordinate geometry to one Al(1), one Al(3), one N(10), and one N(7) atom. The N(6)-N(10) bond length is 1.50 Å. The N(6)-N(7) bond length is 1.52 Å. In the seventh N site, N(7) is bonded in a 4-coordinate geometry to one Yb(1), one Al(3), one Al(4), and one N(6) atom. In the eighth N site, N(8) is bonded in a 4-coordinate geometry to one Yb(2), one Si(1), one Si(2), and one Si(3) atom. In the ninth N site, N(9) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one Yb(1), one Al(4), and one Si(3) atom. In the tenth N site, N(10) is bonded in a 2-coordinate geometry to one Al(2), one Si(3), and one N(6) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), one Ba(2), one Yb(2), and one Al(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ba(1), one Yb(1), one Al(1), and one Al(3) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one Yb(2), one Al(2), and one Al(3) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ba(1), one Yb(1), one Yb(2), and one Al(4) atom.