BaSm5Al3Si9N20O crystallizes in the triclinic P1 space group. Ba(1) is bonded in a body-centered cubic geometry to one N(13), one N(14), one N(15), one N(16), one N(17), one N(18), and two equivalent O(1) atoms. There are five inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 7-coordinate geometry to one N(1), one N(19), one N(2), one N(3), one N(4), one N(5), and one N(6) atom. In the second Sm site, Sm(2) is bonded in a 7-coordinate geometry to one N(1), one N(2), one N(20), one N(3), one N(7), one N(8), and one N(9) atom. In the third Sm site, Sm(3) is bonded to one N(13), one N(17), one N(2), one N(4), one N(8), and one O(1) atom to form SmN5O octahedra that share  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Al(1)N4 tetrahedra,  a cornercorner with one Al(2)N4 tetrahedra,  a cornercorner with one Al(3)N4 tetrahedra,  a cornercorner with one Si(7)N4 tetrahedra,  a cornercorner with one Si(8)N4 tetrahedra,  a cornercorner with one Si(9)N4 tetrahedra, corners with two equivalent Si(1)N4 tetrahedra, and corners with two equivalent Si(5)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 59-60°. In the fourth Sm site, Sm(4) is bonded to one N(14), one N(18), one N(3), one N(5), one N(9), and one O(1) atom to form SmN5O octahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Al(1)N4 tetrahedra,  a cornercorner with one Al(2)N4 tetrahedra,  a cornercorner with one Al(3)N4 tetrahedra,  a cornercorner with one Si(7)N4 tetrahedra,  a cornercorner with one Si(8)N4 tetrahedra,  a cornercorner with one Si(9)N4 tetrahedra, corners with two equivalent Si(2)N4 tetrahedra, and corners with two equivalent Si(6)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 59-61°. In the fifth Sm site, Sm(5) is bonded to one N(1), one N(15), one N(16), one N(6), one N(7), and one O(1) atom to form SmN5O octahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Al(1)N4 tetrahedra,  a cornercorner with one Al(2)N4 tetrahedra,  a cornercorner with one Al(3)N4 tetrahedra,  a cornercorner with one Si(7)N4 tetrahedra,  a cornercorner with one Si(8)N4 tetrahedra,  a cornercorner with one Si(9)N4 tetrahedra, corners with two equivalent Si(3)N4 tetrahedra, and corners with two equivalent Si(4)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 60-61°. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one N(1), one N(12), one N(18), and one N(4) atom to form AlN4 tetrahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Si(1)N4 tetrahedra,  a cornercorner with one Si(3)N4 tetrahedra,  a cornercorner with one Si(4)N4 tetrahedra,  a cornercorner with one Si(6)N4 tetrahedra, and corners with two equivalent Si(9)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 61-67°. In the second Al site, Al(2) is bonded to one N(10), one N(16), one N(2), and one N(5) atom to form AlN4 tetrahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Si(1)N4 tetrahedra,  a cornercorner with one Si(2)N4 tetrahedra,  a cornercorner with one Si(4)N4 tetrahedra,  a cornercorner with one Si(5)N4 tetrahedra, and corners with two equivalent Si(8)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 61-66°. In the third Al site, Al(3) is bonded to one N(11), one N(15), one N(3), and one N(8) atom to form AlN4 tetrahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Si(2)N4 tetrahedra,  a cornercorner with one Si(3)N4 tetrahedra,  a cornercorner with one Si(5)N4 tetrahedra,  a cornercorner with one Si(6)N4 tetrahedra, and corners with two equivalent Si(7)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 61-66°. There are nine inequivalent Si sites. In the first Si site, Si(1) is bonded to one N(10), one N(13), one N(19), and one N(4) atom to form SiN4 tetrahedra that share corners with two equivalent Sm(3)N5O octahedra,  a cornercorner with one Al(1)N4 tetrahedra,  a cornercorner with one Al(2)N4 tetrahedra,  a cornercorner with one Si(2)N4 tetrahedra,  a cornercorner with one Si(3)N4 tetrahedra,  a cornercorner with one Si(5)N4 tetrahedra,  a cornercorner with one Si(8)N4 tetrahedra, and  a cornercorner with one Si(9)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-62°. In the second Si site, Si(2) is bonded to one N(11), one N(14), one N(19), and one N(5) atom to form SiN4 tetrahedra that share corners with two equivalent Sm(4)N5O octahedra,  a cornercorner with one Al(2)N4 tetrahedra,  a cornercorner with one Al(3)N4 tetrahedra,  a cornercorner with one Si(1)N4 tetrahedra,  a cornercorner with one Si(3)N4 tetrahedra,  a cornercorner with one Si(6)N4 tetrahedra,  a cornercorner with one Si(7)N4 tetrahedra, and  a cornercorner with one Si(8)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-61°. In the third Si site, Si(3) is bonded to one N(12), one N(15), one N(19), and one N(6) atom to form SiN4 tetrahedra that share corners with two equivalent Sm(5)N5O octahedra,  a cornercorner with one Al(1)N4 tetrahedra,  a cornercorner with one Al(3)N4 tetrahedra,  a cornercorner with one Si(1)N4 tetrahedra,  a cornercorner with one Si(2)N4 tetrahedra,  a cornercorner with one Si(4)N4 tetrahedra,  a cornercorner with one Si(7)N4 tetrahedra, and  a cornercorner with one Si(9)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-59°. In the fourth Si site, Si(4) is bonded to one N(12), one N(16), one N(20), and one N(7) atom to form SiN4 tetrahedra that share corners with two equivalent Sm(5)N5O octahedra,  a cornercorner with one Al(1)N4 tetrahedra,  a cornercorner with one Al(2)N4 tetrahedra,  a cornercorner with one Si(3)N4 tetrahedra,  a cornercorner with one Si(5)N4 tetrahedra,  a cornercorner with one Si(6)N4 tetrahedra,  a cornercorner with one Si(8)N4 tetrahedra, and  a cornercorner with one Si(9)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-60°. In the fifth Si site, Si(5) is bonded to one N(10), one N(17), one N(20), and one N(8) atom to form SiN4 tetrahedra that share corners with two equivalent Sm(3)N5O octahedra,  a cornercorner with one Al(2)N4 tetrahedra,  a cornercorner with one Al(3)N4 tetrahedra,  a cornercorner with one Si(1)N4 tetrahedra,  a cornercorner with one Si(4)N4 tetrahedra,  a cornercorner with one Si(6)N4 tetrahedra,  a cornercorner with one Si(7)N4 tetrahedra, and  a cornercorner with one Si(8)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-61°. In the sixth Si site, Si(6) is bonded to one N(11), one N(18), one N(20), and one N(9) atom to form SiN4 tetrahedra that share corners with two equivalent Sm(4)N5O octahedra,  a cornercorner with one Al(1)N4 tetrahedra,  a cornercorner with one Al(3)N4 tetrahedra,  a cornercorner with one Si(2)N4 tetrahedra,  a cornercorner with one Si(4)N4 tetrahedra,  a cornercorner with one Si(5)N4 tetrahedra,  a cornercorner with one Si(7)N4 tetrahedra, and  a cornercorner with one Si(9)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-58°. In the seventh Si site, Si(7) is bonded to one N(11), one N(17), one N(3), and one N(6) atom to form SiN4 tetrahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Si(2)N4 tetrahedra,  a cornercorner with one Si(3)N4 tetrahedra,  a cornercorner with one Si(5)N4 tetrahedra,  a cornercorner with one Si(6)N4 tetrahedra, and corners with two equivalent Al(3)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-64°. In the eighth Si site, Si(8) is bonded to one N(10), one N(14), one N(2), and one N(7) atom to form SiN4 tetrahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Si(1)N4 tetrahedra,  a cornercorner with one Si(2)N4 tetrahedra,  a cornercorner with one Si(4)N4 tetrahedra,  a cornercorner with one Si(5)N4 tetrahedra, and corners with two equivalent Al(2)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-63°. In the ninth Si site, Si(9) is bonded to one N(1), one N(12), one N(13), and one N(9) atom to form SiN4 tetrahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Si(1)N4 tetrahedra,  a cornercorner with one Si(3)N4 tetrahedra,  a cornercorner with one Si(4)N4 tetrahedra,  a cornercorner with one Si(6)N4 tetrahedra, and corners with two equivalent Al(1)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-64°. There are twenty inequivalent N sites. In the first N site, N(1) is bonded to one Sm(1), one Sm(2), one Sm(5), one Al(1), and one Si(9) atom to form distorted NSm3AlSi trigonal bipyramids that share  a cornercorner with one N(5)Sm2AlSi tetrahedra,  a cornercorner with one N(8)Sm2AlSi tetrahedra,  a cornercorner with one N(19)SmSi3 tetrahedra,  a cornercorner with one N(20)SmSi3 tetrahedra, corners with two equivalent N(12)AlSi3 tetrahedra,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid, corners with two equivalent N(2)Sm3AlSi trigonal bipyramids, corners with two equivalent N(3)Sm3AlSi trigonal bipyramids,  an edgeedge with one N(4)Sm2AlSi tetrahedra,  an edgeedge with one N(6)Sm2Si2 tetrahedra,  an edgeedge with one N(7)Sm2Si2 tetrahedra, and  an edgeedge with one N(9)Sm2Si2 tetrahedra. In the second N site, N(2) is bonded to one Sm(1), one Sm(2), one Sm(3), one Al(2), and one Si(8) atom to form distorted NSm3AlSi trigonal bipyramids that share  a cornercorner with one N(6)Sm2Si2 tetrahedra,  a cornercorner with one N(9)Sm2Si2 tetrahedra,  a cornercorner with one N(19)SmSi3 tetrahedra,  a cornercorner with one N(20)SmSi3 tetrahedra, corners with two equivalent N(10)AlSi3 tetrahedra,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid, corners with two equivalent N(1)Sm3AlSi trigonal bipyramids, corners with two equivalent N(3)Sm3AlSi trigonal bipyramids,  an edgeedge with one N(4)Sm2AlSi tetrahedra,  an edgeedge with one N(5)Sm2AlSi tetrahedra,  an edgeedge with one N(8)Sm2AlSi tetrahedra, and  an edgeedge with one N(7)Sm2Si2 tetrahedra. In the third N site, N(3) is bonded to one Sm(1), one Sm(2), one Sm(4), one Al(3), and one Si(7) atom to form distorted NSm3AlSi trigonal bipyramids that share  a cornercorner with one N(4)Sm2AlSi tetrahedra,  a cornercorner with one N(7)Sm2Si2 tetrahedra,  a cornercorner with one N(19)SmSi3 tetrahedra,  a cornercorner with one N(20)SmSi3 tetrahedra, corners with two equivalent N(11)AlSi3 tetrahedra,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid, corners with two equivalent N(1)Sm3AlSi trigonal bipyramids, corners with two equivalent N(2)Sm3AlSi trigonal bipyramids,  an edgeedge with one N(5)Sm2AlSi tetrahedra,  an edgeedge with one N(8)Sm2AlSi tetrahedra,  an edgeedge with one N(6)Sm2Si2 tetrahedra, and  an edgeedge with one N(9)Sm2Si2 tetrahedra. In the fourth N site, N(4) is bonded to one Sm(1), one Sm(3), one Al(1), and one Si(1) atom to form distorted NSm2AlSi tetrahedra that share  a cornercorner with one N(10)AlSi3 tetrahedra,  a cornercorner with one N(12)AlSi3 tetrahedra,  a cornercorner with one N(5)Sm2AlSi tetrahedra,  a cornercorner with one N(8)Sm2AlSi tetrahedra,  a cornercorner with one N(6)Sm2Si2 tetrahedra, corners with two equivalent N(19)SmSi3 tetrahedra,  a cornercorner with one N(3)Sm3AlSi trigonal bipyramid,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid,  an edgeedge with one N(1)Sm3AlSi trigonal bipyramid, and  an edgeedge with one N(2)Sm3AlSi trigonal bipyramid. In the fifth N site, N(5) is bonded to one Sm(1), one Sm(4), one Al(2), and one Si(2) atom to form distorted NSm2AlSi tetrahedra that share  a cornercorner with one N(10)AlSi3 tetrahedra,  a cornercorner with one N(11)AlSi3 tetrahedra,  a cornercorner with one N(4)Sm2AlSi tetrahedra,  a cornercorner with one N(6)Sm2Si2 tetrahedra,  a cornercorner with one N(9)Sm2Si2 tetrahedra, corners with two equivalent N(19)SmSi3 tetrahedra,  a cornercorner with one N(1)Sm3AlSi trigonal bipyramid,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid,  an edgeedge with one N(2)Sm3AlSi trigonal bipyramid, and  an edgeedge with one N(3)Sm3AlSi trigonal bipyramid. In the sixth N site, N(6) is bonded to one Sm(1), one Sm(5), one Si(3), and one Si(7) atom to form distorted NSm2Si2 tetrahedra that share  a cornercorner with one N(11)AlSi3 tetrahedra,  a cornercorner with one N(12)AlSi3 tetrahedra,  a cornercorner with one N(4)Sm2AlSi tetrahedra,  a cornercorner with one N(5)Sm2AlSi tetrahedra,  a cornercorner with one N(7)Sm2Si2 tetrahedra, corners with two equivalent N(19)SmSi3 tetrahedra,  a cornercorner with one N(2)Sm3AlSi trigonal bipyramid,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid,  an edgeedge with one N(1)Sm3AlSi trigonal bipyramid, and  an edgeedge with one N(3)Sm3AlSi trigonal bipyramid. In the seventh N site, N(7) is bonded to one Sm(2), one Sm(5), one Si(4), and one Si(8) atom to form distorted NSm2Si2 tetrahedra that share  a cornercorner with one N(10)AlSi3 tetrahedra,  a cornercorner with one N(12)AlSi3 tetrahedra,  a cornercorner with one N(8)Sm2AlSi tetrahedra,  a cornercorner with one N(6)Sm2Si2 tetrahedra,  a cornercorner with one N(9)Sm2Si2 tetrahedra, corners with two equivalent N(20)SmSi3 tetrahedra,  a cornercorner with one N(3)Sm3AlSi trigonal bipyramid,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid,  an edgeedge with one N(1)Sm3AlSi trigonal bipyramid, and  an edgeedge with one N(2)Sm3AlSi trigonal bipyramid. In the eighth N site, N(8) is bonded to one Sm(2), one Sm(3), one Al(3), and one Si(5) atom to form distorted NSm2AlSi tetrahedra that share  a cornercorner with one N(10)AlSi3 tetrahedra,  a cornercorner with one N(11)AlSi3 tetrahedra,  a cornercorner with one N(4)Sm2AlSi tetrahedra,  a cornercorner with one N(7)Sm2Si2 tetrahedra,  a cornercorner with one N(9)Sm2Si2 tetrahedra, corners with two equivalent N(20)SmSi3 tetrahedra,  a cornercorner with one N(1)Sm3AlSi trigonal bipyramid,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid,  an edgeedge with one N(2)Sm3AlSi trigonal bipyramid, and  an edgeedge with one N(3)Sm3AlSi trigonal bipyramid. In the ninth N site, N(9) is bonded to one Sm(2), one Sm(4), one Si(6), and one Si(9) atom to form distorted NSm2Si2 tetrahedra that share  a cornercorner with one N(11)AlSi3 tetrahedra,  a cornercorner with one N(12)AlSi3 tetrahedra,  a cornercorner with one N(5)Sm2AlSi tetrahedra,  a cornercorner with one N(8)Sm2AlSi tetrahedra,  a cornercorner with one N(7)Sm2Si2 tetrahedra, corners with two equivalent N(20)SmSi3 tetrahedra,  a cornercorner with one N(2)Sm3AlSi trigonal bipyramid,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid,  an edgeedge with one N(1)Sm3AlSi trigonal bipyramid, and  an edgeedge with one N(3)Sm3AlSi trigonal bipyramid. In the tenth N site, N(10) is bonded to one Al(2), one Si(1), one Si(5), and one Si(8) atom to form NAlSi3 tetrahedra that share  a cornercorner with one N(4)Sm2AlSi tetrahedra,  a cornercorner with one N(5)Sm2AlSi tetrahedra,  a cornercorner with one N(8)Sm2AlSi tetrahedra,  a cornercorner with one N(7)Sm2Si2 tetrahedra,  a cornercorner with one N(19)SmSi3 tetrahedra,  a cornercorner with one N(20)SmSi3 tetrahedra, and corners with two equivalent N(2)Sm3AlSi trigonal bipyramids. In the eleventh N site, N(11) is bonded to one Al(3), one Si(2), one Si(6), and one Si(7) atom to form NAlSi3 tetrahedra that share  a cornercorner with one N(5)Sm2AlSi tetrahedra,  a cornercorner with one N(8)Sm2AlSi tetrahedra,  a cornercorner with one N(6)Sm2Si2 tetrahedra,  a cornercorner with one N(9)Sm2Si2 tetrahedra,  a cornercorner with one N(19)SmSi3 tetrahedra,  a cornercorner with one N(20)SmSi3 tetrahedra, and corners with two equivalent N(3)Sm3AlSi trigonal bipyramids. In the twelfth N site, N(12) is bonded to one Al(1), one Si(3), one Si(4), and one Si(9) atom to form NAlSi3 tetrahedra that share  a cornercorner with one N(4)Sm2AlSi tetrahedra,  a cornercorner with one N(6)Sm2Si2 tetrahedra,  a cornercorner with one N(7)Sm2Si2 tetrahedra,  a cornercorner with one N(9)Sm2Si2 tetrahedra,  a cornercorner with one N(19)SmSi3 tetrahedra,  a cornercorner with one N(20)SmSi3 tetrahedra, and corners with two equivalent N(1)Sm3AlSi trigonal bipyramids. In the thirteenth N site, N(13) is bonded in a 3-coordinate geometry to one Ba(1), one Sm(3), one Si(1), and one Si(9) atom. In the fourteenth N site, N(14) is bonded in a 3-coordinate geometry to one Ba(1), one Sm(4), one Si(2), and one Si(8) atom. In the fifteenth N site, N(15) is bonded in a 3-coordinate geometry to one Ba(1), one Sm(5), one Al(3), and one Si(3) atom. In the sixteenth N site, N(16) is bonded in a 3-coordinate geometry to one Ba(1), one Sm(5), one Al(2), and one Si(4) atom. In the seventeenth N site, N(17) is bonded in a 3-coordinate geometry to one Ba(1), one Sm(3), one Si(5), and one Si(7) atom. In the eighteenth N site, N(18) is bonded in a 3-coordinate geometry to one Ba(1), one Sm(4), one Al(1), and one Si(6) atom. In the nineteenth N site, N(19) is bonded to one Sm(1), one Si(1), one Si(2), and one Si(3) atom to form distorted NSmSi3 tetrahedra that share  a cornercorner with one N(10)AlSi3 tetrahedra,  a cornercorner with one N(11)AlSi3 tetrahedra,  a cornercorner with one N(12)AlSi3 tetrahedra, corners with two equivalent N(4)Sm2AlSi tetrahedra, corners with two equivalent N(5)Sm2AlSi tetrahedra, corners with two equivalent N(6)Sm2Si2 tetrahedra,  a cornercorner with one N(1)Sm3AlSi trigonal bipyramid,  a cornercorner with one N(2)Sm3AlSi trigonal bipyramid, and  a cornercorner with one N(3)Sm3AlSi trigonal bipyramid. In the twentieth N site, N(20) is bonded to one Sm(2), one Si(4), one Si(5), and one Si(6) atom to form distorted NSmSi3 tetrahedra that share  a cornercorner with one N(10)AlSi3 tetrahedra,  a cornercorner with one N(11)AlSi3 tetrahedra,  a cornercorner with one N(12)AlSi3 tetrahedra, corners with two equivalent N(8)Sm2AlSi tetrahedra, corners with two equivalent N(7)Sm2Si2 tetrahedra, corners with two equivalent N(9)Sm2Si2 tetrahedra,  a cornercorner with one N(1)Sm3AlSi trigonal bipyramid,  a cornercorner with one N(2)Sm3AlSi trigonal bipyramid, and  a cornercorner with one N(3)Sm3AlSi trigonal bipyramid. O(1) is bonded to two equivalent Ba(1), one Sm(3), one Sm(4), and one Sm(5) atom to form OBa2Sm3 trigonal bipyramids that share  a cornercorner with one N(4)Sm2AlSi tetrahedra,  a cornercorner with one N(5)Sm2AlSi tetrahedra,  a cornercorner with one N(8)Sm2AlSi tetrahedra,  a cornercorner with one N(6)Sm2Si2 tetrahedra,  a cornercorner with one N(7)Sm2Si2 tetrahedra,  a cornercorner with one N(9)Sm2Si2 tetrahedra,  a cornercorner with one N(1)Sm3AlSi trigonal bipyramid,  a cornercorner with one N(2)Sm3AlSi trigonal bipyramid,  a cornercorner with one N(3)Sm3AlSi trigonal bipyramid, and corners with two equivalent O(1)Ba2Sm3 trigonal bipyramids.
BaSm5Al3Si9N20O crystallizes in the triclinic P1 space group. Ba(1) is bonded in a body-centered cubic geometry to one N(13), one N(14), one N(15), one N(16), one N(17), one N(18), and two equivalent O(1) atoms. The Ba(1)-N(13) bond length is 3.24 Å. The Ba(1)-N(14) bond length is 3.22 Å. The Ba(1)-N(15) bond length is 3.13 Å. The Ba(1)-N(16) bond length is 3.15 Å. The Ba(1)-N(17) bond length is 3.24 Å. The Ba(1)-N(18) bond length is 3.16 Å. Both Ba(1)-O(1) bond lengths are 3.09 Å. There are five inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 7-coordinate geometry to one N(1), one N(19), one N(2), one N(3), one N(4), one N(5), and one N(6) atom. The Sm(1)-N(1) bond length is 2.76 Å. The Sm(1)-N(19) bond length is 2.63 Å. The Sm(1)-N(2) bond length is 2.71 Å. The Sm(1)-N(3) bond length is 2.82 Å. The Sm(1)-N(4) bond length is 2.52 Å. The Sm(1)-N(5) bond length is 2.51 Å. The Sm(1)-N(6) bond length is 2.59 Å. In the second Sm site, Sm(2) is bonded in a 7-coordinate geometry to one N(1), one N(2), one N(20), one N(3), one N(7), one N(8), and one N(9) atom. The Sm(2)-N(1) bond length is 2.81 Å. The Sm(2)-N(2) bond length is 2.78 Å. The Sm(2)-N(20) bond length is 2.64 Å. The Sm(2)-N(3) bond length is 2.72 Å. The Sm(2)-N(7) bond length is 2.57 Å. The Sm(2)-N(8) bond length is 2.51 Å. The Sm(2)-N(9) bond length is 2.58 Å. In the third Sm site, Sm(3) is bonded to one N(13), one N(17), one N(2), one N(4), one N(8), and one O(1) atom to form SmN5O octahedra that share  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Al(1)N4 tetrahedra,  a cornercorner with one Al(2)N4 tetrahedra,  a cornercorner with one Al(3)N4 tetrahedra,  a cornercorner with one Si(7)N4 tetrahedra,  a cornercorner with one Si(8)N4 tetrahedra,  a cornercorner with one Si(9)N4 tetrahedra, corners with two equivalent Si(1)N4 tetrahedra, and corners with two equivalent Si(5)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 59-60°. The Sm(3)-N(13) bond length is 2.46 Å. The Sm(3)-N(17) bond length is 2.47 Å. The Sm(3)-N(2) bond length is 2.51 Å. The Sm(3)-N(4) bond length is 2.43 Å. The Sm(3)-N(8) bond length is 2.42 Å. The Sm(3)-O(1) bond length is 2.38 Å. In the fourth Sm site, Sm(4) is bonded to one N(14), one N(18), one N(3), one N(5), one N(9), and one O(1) atom to form SmN5O octahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Al(1)N4 tetrahedra,  a cornercorner with one Al(2)N4 tetrahedra,  a cornercorner with one Al(3)N4 tetrahedra,  a cornercorner with one Si(7)N4 tetrahedra,  a cornercorner with one Si(8)N4 tetrahedra,  a cornercorner with one Si(9)N4 tetrahedra, corners with two equivalent Si(2)N4 tetrahedra, and corners with two equivalent Si(6)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 59-61°. The Sm(4)-N(14) bond length is 2.48 Å. The Sm(4)-N(18) bond length is 2.36 Å. The Sm(4)-N(3) bond length is 2.51 Å. The Sm(4)-N(5) bond length is 2.41 Å. The Sm(4)-N(9) bond length is 2.51 Å. The Sm(4)-O(1) bond length is 2.39 Å. In the fifth Sm site, Sm(5) is bonded to one N(1), one N(15), one N(16), one N(6), one N(7), and one O(1) atom to form SmN5O octahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Al(1)N4 tetrahedra,  a cornercorner with one Al(2)N4 tetrahedra,  a cornercorner with one Al(3)N4 tetrahedra,  a cornercorner with one Si(7)N4 tetrahedra,  a cornercorner with one Si(8)N4 tetrahedra,  a cornercorner with one Si(9)N4 tetrahedra, corners with two equivalent Si(3)N4 tetrahedra, and corners with two equivalent Si(4)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 60-61°. The Sm(5)-N(1) bond length is 2.51 Å. The Sm(5)-N(15) bond length is 2.37 Å. The Sm(5)-N(16) bond length is 2.38 Å. The Sm(5)-N(6) bond length is 2.50 Å. The Sm(5)-N(7) bond length is 2.49 Å. The Sm(5)-O(1) bond length is 2.39 Å. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one N(1), one N(12), one N(18), and one N(4) atom to form AlN4 tetrahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Si(1)N4 tetrahedra,  a cornercorner with one Si(3)N4 tetrahedra,  a cornercorner with one Si(4)N4 tetrahedra,  a cornercorner with one Si(6)N4 tetrahedra, and corners with two equivalent Si(9)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 61-67°. The Al(1)-N(1) bond length is 1.86 Å. The Al(1)-N(12) bond length is 2.06 Å. The Al(1)-N(18) bond length is 1.85 Å. The Al(1)-N(4) bond length is 1.84 Å. In the second Al site, Al(2) is bonded to one N(10), one N(16), one N(2), and one N(5) atom to form AlN4 tetrahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Si(1)N4 tetrahedra,  a cornercorner with one Si(2)N4 tetrahedra,  a cornercorner with one Si(4)N4 tetrahedra,  a cornercorner with one Si(5)N4 tetrahedra, and corners with two equivalent Si(8)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 61-66°. The Al(2)-N(10) bond length is 2.05 Å. The Al(2)-N(16) bond length is 1.86 Å. The Al(2)-N(2) bond length is 1.86 Å. The Al(2)-N(5) bond length is 1.83 Å. In the third Al site, Al(3) is bonded to one N(11), one N(15), one N(3), and one N(8) atom to form AlN4 tetrahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Si(2)N4 tetrahedra,  a cornercorner with one Si(3)N4 tetrahedra,  a cornercorner with one Si(5)N4 tetrahedra,  a cornercorner with one Si(6)N4 tetrahedra, and corners with two equivalent Si(7)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 61-66°. The Al(3)-N(11) bond length is 2.04 Å. The Al(3)-N(15) bond length is 1.84 Å. The Al(3)-N(3) bond length is 1.86 Å. The Al(3)-N(8) bond length is 1.83 Å. There are nine inequivalent Si sites. In the first Si site, Si(1) is bonded to one N(10), one N(13), one N(19), and one N(4) atom to form SiN4 tetrahedra that share corners with two equivalent Sm(3)N5O octahedra,  a cornercorner with one Al(1)N4 tetrahedra,  a cornercorner with one Al(2)N4 tetrahedra,  a cornercorner with one Si(2)N4 tetrahedra,  a cornercorner with one Si(3)N4 tetrahedra,  a cornercorner with one Si(5)N4 tetrahedra,  a cornercorner with one Si(8)N4 tetrahedra, and  a cornercorner with one Si(9)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-62°. The Si(1)-N(10) bond length is 1.81 Å. The Si(1)-N(13) bond length is 1.74 Å. The Si(1)-N(19) bond length is 1.77 Å. The Si(1)-N(4) bond length is 1.70 Å. In the second Si site, Si(2) is bonded to one N(11), one N(14), one N(19), and one N(5) atom to form SiN4 tetrahedra that share corners with two equivalent Sm(4)N5O octahedra,  a cornercorner with one Al(2)N4 tetrahedra,  a cornercorner with one Al(3)N4 tetrahedra,  a cornercorner with one Si(1)N4 tetrahedra,  a cornercorner with one Si(3)N4 tetrahedra,  a cornercorner with one Si(6)N4 tetrahedra,  a cornercorner with one Si(7)N4 tetrahedra, and  a cornercorner with one Si(8)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-61°. The Si(2)-N(11) bond length is 1.82 Å. The Si(2)-N(14) bond length is 1.73 Å. The Si(2)-N(19) bond length is 1.78 Å. The Si(2)-N(5) bond length is 1.69 Å. In the third Si site, Si(3) is bonded to one N(12), one N(15), one N(19), and one N(6) atom to form SiN4 tetrahedra that share corners with two equivalent Sm(5)N5O octahedra,  a cornercorner with one Al(1)N4 tetrahedra,  a cornercorner with one Al(3)N4 tetrahedra,  a cornercorner with one Si(1)N4 tetrahedra,  a cornercorner with one Si(2)N4 tetrahedra,  a cornercorner with one Si(4)N4 tetrahedra,  a cornercorner with one Si(7)N4 tetrahedra, and  a cornercorner with one Si(9)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-59°. The Si(3)-N(12) bond length is 1.81 Å. The Si(3)-N(15) bond length is 1.69 Å. The Si(3)-N(19) bond length is 1.78 Å. The Si(3)-N(6) bond length is 1.73 Å. In the fourth Si site, Si(4) is bonded to one N(12), one N(16), one N(20), and one N(7) atom to form SiN4 tetrahedra that share corners with two equivalent Sm(5)N5O octahedra,  a cornercorner with one Al(1)N4 tetrahedra,  a cornercorner with one Al(2)N4 tetrahedra,  a cornercorner with one Si(3)N4 tetrahedra,  a cornercorner with one Si(5)N4 tetrahedra,  a cornercorner with one Si(6)N4 tetrahedra,  a cornercorner with one Si(8)N4 tetrahedra, and  a cornercorner with one Si(9)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-60°. The Si(4)-N(12) bond length is 1.81 Å. The Si(4)-N(16) bond length is 1.69 Å. The Si(4)-N(20) bond length is 1.78 Å. The Si(4)-N(7) bond length is 1.73 Å. In the fifth Si site, Si(5) is bonded to one N(10), one N(17), one N(20), and one N(8) atom to form SiN4 tetrahedra that share corners with two equivalent Sm(3)N5O octahedra,  a cornercorner with one Al(2)N4 tetrahedra,  a cornercorner with one Al(3)N4 tetrahedra,  a cornercorner with one Si(1)N4 tetrahedra,  a cornercorner with one Si(4)N4 tetrahedra,  a cornercorner with one Si(6)N4 tetrahedra,  a cornercorner with one Si(7)N4 tetrahedra, and  a cornercorner with one Si(8)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-61°. The Si(5)-N(10) bond length is 1.82 Å. The Si(5)-N(17) bond length is 1.74 Å. The Si(5)-N(20) bond length is 1.78 Å. The Si(5)-N(8) bond length is 1.69 Å. In the sixth Si site, Si(6) is bonded to one N(11), one N(18), one N(20), and one N(9) atom to form SiN4 tetrahedra that share corners with two equivalent Sm(4)N5O octahedra,  a cornercorner with one Al(1)N4 tetrahedra,  a cornercorner with one Al(3)N4 tetrahedra,  a cornercorner with one Si(2)N4 tetrahedra,  a cornercorner with one Si(4)N4 tetrahedra,  a cornercorner with one Si(5)N4 tetrahedra,  a cornercorner with one Si(7)N4 tetrahedra, and  a cornercorner with one Si(9)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-58°. The Si(6)-N(11) bond length is 1.81 Å. The Si(6)-N(18) bond length is 1.69 Å. The Si(6)-N(20) bond length is 1.78 Å. The Si(6)-N(9) bond length is 1.73 Å. In the seventh Si site, Si(7) is bonded to one N(11), one N(17), one N(3), and one N(6) atom to form SiN4 tetrahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Si(2)N4 tetrahedra,  a cornercorner with one Si(3)N4 tetrahedra,  a cornercorner with one Si(5)N4 tetrahedra,  a cornercorner with one Si(6)N4 tetrahedra, and corners with two equivalent Al(3)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-64°. The Si(7)-N(11) bond length is 1.93 Å. The Si(7)-N(17) bond length is 1.76 Å. The Si(7)-N(3) bond length is 1.72 Å. The Si(7)-N(6) bond length is 1.74 Å. In the eighth Si site, Si(8) is bonded to one N(10), one N(14), one N(2), and one N(7) atom to form SiN4 tetrahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Si(1)N4 tetrahedra,  a cornercorner with one Si(2)N4 tetrahedra,  a cornercorner with one Si(4)N4 tetrahedra,  a cornercorner with one Si(5)N4 tetrahedra, and corners with two equivalent Al(2)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-63°. The Si(8)-N(10) bond length is 1.91 Å. The Si(8)-N(14) bond length is 1.76 Å. The Si(8)-N(2) bond length is 1.71 Å. The Si(8)-N(7) bond length is 1.73 Å. In the ninth Si site, Si(9) is bonded to one N(1), one N(12), one N(13), and one N(9) atom to form SiN4 tetrahedra that share  a cornercorner with one Sm(3)N5O octahedra,  a cornercorner with one Sm(4)N5O octahedra,  a cornercorner with one Sm(5)N5O octahedra,  a cornercorner with one Si(1)N4 tetrahedra,  a cornercorner with one Si(3)N4 tetrahedra,  a cornercorner with one Si(4)N4 tetrahedra,  a cornercorner with one Si(6)N4 tetrahedra, and corners with two equivalent Al(1)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-64°. The Si(9)-N(1) bond length is 1.72 Å. The Si(9)-N(12) bond length is 1.91 Å. The Si(9)-N(13) bond length is 1.75 Å. The Si(9)-N(9) bond length is 1.74 Å. There are twenty inequivalent N sites. In the first N site, N(1) is bonded to one Sm(1), one Sm(2), one Sm(5), one Al(1), and one Si(9) atom to form distorted NSm3AlSi trigonal bipyramids that share  a cornercorner with one N(5)Sm2AlSi tetrahedra,  a cornercorner with one N(8)Sm2AlSi tetrahedra,  a cornercorner with one N(19)SmSi3 tetrahedra,  a cornercorner with one N(20)SmSi3 tetrahedra, corners with two equivalent N(12)AlSi3 tetrahedra,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid, corners with two equivalent N(2)Sm3AlSi trigonal bipyramids, corners with two equivalent N(3)Sm3AlSi trigonal bipyramids,  an edgeedge with one N(4)Sm2AlSi tetrahedra,  an edgeedge with one N(6)Sm2Si2 tetrahedra,  an edgeedge with one N(7)Sm2Si2 tetrahedra, and  an edgeedge with one N(9)Sm2Si2 tetrahedra. In the second N site, N(2) is bonded to one Sm(1), one Sm(2), one Sm(3), one Al(2), and one Si(8) atom to form distorted NSm3AlSi trigonal bipyramids that share  a cornercorner with one N(6)Sm2Si2 tetrahedra,  a cornercorner with one N(9)Sm2Si2 tetrahedra,  a cornercorner with one N(19)SmSi3 tetrahedra,  a cornercorner with one N(20)SmSi3 tetrahedra, corners with two equivalent N(10)AlSi3 tetrahedra,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid, corners with two equivalent N(1)Sm3AlSi trigonal bipyramids, corners with two equivalent N(3)Sm3AlSi trigonal bipyramids,  an edgeedge with one N(4)Sm2AlSi tetrahedra,  an edgeedge with one N(5)Sm2AlSi tetrahedra,  an edgeedge with one N(8)Sm2AlSi tetrahedra, and  an edgeedge with one N(7)Sm2Si2 tetrahedra. In the third N site, N(3) is bonded to one Sm(1), one Sm(2), one Sm(4), one Al(3), and one Si(7) atom to form distorted NSm3AlSi trigonal bipyramids that share  a cornercorner with one N(4)Sm2AlSi tetrahedra,  a cornercorner with one N(7)Sm2Si2 tetrahedra,  a cornercorner with one N(19)SmSi3 tetrahedra,  a cornercorner with one N(20)SmSi3 tetrahedra, corners with two equivalent N(11)AlSi3 tetrahedra,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid, corners with two equivalent N(1)Sm3AlSi trigonal bipyramids, corners with two equivalent N(2)Sm3AlSi trigonal bipyramids,  an edgeedge with one N(5)Sm2AlSi tetrahedra,  an edgeedge with one N(8)Sm2AlSi tetrahedra,  an edgeedge with one N(6)Sm2Si2 tetrahedra, and  an edgeedge with one N(9)Sm2Si2 tetrahedra. In the fourth N site, N(4) is bonded to one Sm(1), one Sm(3), one Al(1), and one Si(1) atom to form distorted NSm2AlSi tetrahedra that share  a cornercorner with one N(10)AlSi3 tetrahedra,  a cornercorner with one N(12)AlSi3 tetrahedra,  a cornercorner with one N(5)Sm2AlSi tetrahedra,  a cornercorner with one N(8)Sm2AlSi tetrahedra,  a cornercorner with one N(6)Sm2Si2 tetrahedra, corners with two equivalent N(19)SmSi3 tetrahedra,  a cornercorner with one N(3)Sm3AlSi trigonal bipyramid,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid,  an edgeedge with one N(1)Sm3AlSi trigonal bipyramid, and  an edgeedge with one N(2)Sm3AlSi trigonal bipyramid. In the fifth N site, N(5) is bonded to one Sm(1), one Sm(4), one Al(2), and one Si(2) atom to form distorted NSm2AlSi tetrahedra that share  a cornercorner with one N(10)AlSi3 tetrahedra,  a cornercorner with one N(11)AlSi3 tetrahedra,  a cornercorner with one N(4)Sm2AlSi tetrahedra,  a cornercorner with one N(6)Sm2Si2 tetrahedra,  a cornercorner with one N(9)Sm2Si2 tetrahedra, corners with two equivalent N(19)SmSi3 tetrahedra,  a cornercorner with one N(1)Sm3AlSi trigonal bipyramid,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid,  an edgeedge with one N(2)Sm3AlSi trigonal bipyramid, and  an edgeedge with one N(3)Sm3AlSi trigonal bipyramid. In the sixth N site, N(6) is bonded to one Sm(1), one Sm(5), one Si(3), and one Si(7) atom to form distorted NSm2Si2 tetrahedra that share  a cornercorner with one N(11)AlSi3 tetrahedra,  a cornercorner with one N(12)AlSi3 tetrahedra,  a cornercorner with one N(4)Sm2AlSi tetrahedra,  a cornercorner with one N(5)Sm2AlSi tetrahedra,  a cornercorner with one N(7)Sm2Si2 tetrahedra, corners with two equivalent N(19)SmSi3 tetrahedra,  a cornercorner with one N(2)Sm3AlSi trigonal bipyramid,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid,  an edgeedge with one N(1)Sm3AlSi trigonal bipyramid, and  an edgeedge with one N(3)Sm3AlSi trigonal bipyramid. In the seventh N site, N(7) is bonded to one Sm(2), one Sm(5), one Si(4), and one Si(8) atom to form distorted NSm2Si2 tetrahedra that share  a cornercorner with one N(10)AlSi3 tetrahedra,  a cornercorner with one N(12)AlSi3 tetrahedra,  a cornercorner with one N(8)Sm2AlSi tetrahedra,  a cornercorner with one N(6)Sm2Si2 tetrahedra,  a cornercorner with one N(9)Sm2Si2 tetrahedra, corners with two equivalent N(20)SmSi3 tetrahedra,  a cornercorner with one N(3)Sm3AlSi trigonal bipyramid,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid,  an edgeedge with one N(1)Sm3AlSi trigonal bipyramid, and  an edgeedge with one N(2)Sm3AlSi trigonal bipyramid. In the eighth N site, N(8) is bonded to one Sm(2), one Sm(3), one Al(3), and one Si(5) atom to form distorted NSm2AlSi tetrahedra that share  a cornercorner with one N(10)AlSi3 tetrahedra,  a cornercorner with one N(11)AlSi3 tetrahedra,  a cornercorner with one N(4)Sm2AlSi tetrahedra,  a cornercorner with one N(7)Sm2Si2 tetrahedra,  a cornercorner with one N(9)Sm2Si2 tetrahedra, corners with two equivalent N(20)SmSi3 tetrahedra,  a cornercorner with one N(1)Sm3AlSi trigonal bipyramid,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid,  an edgeedge with one N(2)Sm3AlSi trigonal bipyramid, and  an edgeedge with one N(3)Sm3AlSi trigonal bipyramid. In the ninth N site, N(9) is bonded to one Sm(2), one Sm(4), one Si(6), and one Si(9) atom to form distorted NSm2Si2 tetrahedra that share  a cornercorner with one N(11)AlSi3 tetrahedra,  a cornercorner with one N(12)AlSi3 tetrahedra,  a cornercorner with one N(5)Sm2AlSi tetrahedra,  a cornercorner with one N(8)Sm2AlSi tetrahedra,  a cornercorner with one N(7)Sm2Si2 tetrahedra, corners with two equivalent N(20)SmSi3 tetrahedra,  a cornercorner with one N(2)Sm3AlSi trigonal bipyramid,  a cornercorner with one O(1)Ba2Sm3 trigonal bipyramid,  an edgeedge with one N(1)Sm3AlSi trigonal bipyramid, and  an edgeedge with one N(3)Sm3AlSi trigonal bipyramid. In the tenth N site, N(10) is bonded to one Al(2), one Si(1), one Si(5), and one Si(8) atom to form NAlSi3 tetrahedra that share  a cornercorner with one N(4)Sm2AlSi tetrahedra,  a cornercorner with one N(5)Sm2AlSi tetrahedra,  a cornercorner with one N(8)Sm2AlSi tetrahedra,  a cornercorner with one N(7)Sm2Si2 tetrahedra,  a cornercorner with one N(19)SmSi3 tetrahedra,  a cornercorner with one N(20)SmSi3 tetrahedra, and corners with two equivalent N(2)Sm3AlSi trigonal bipyramids. In the eleventh N site, N(11) is bonded to one Al(3), one Si(2), one Si(6), and one Si(7) atom to form NAlSi3 tetrahedra that share  a cornercorner with one N(5)Sm2AlSi tetrahedra,  a cornercorner with one N(8)Sm2AlSi tetrahedra,  a cornercorner with one N(6)Sm2Si2 tetrahedra,  a cornercorner with one N(9)Sm2Si2 tetrahedra,  a cornercorner with one N(19)SmSi3 tetrahedra,  a cornercorner with one N(20)SmSi3 tetrahedra, and corners with two equivalent N(3)Sm3AlSi trigonal bipyramids. In the twelfth N site, N(12) is bonded to one Al(1), one Si(3), one Si(4), and one Si(9) atom to form NAlSi3 tetrahedra that share  a cornercorner with one N(4)Sm2AlSi tetrahedra,  a cornercorner with one N(6)Sm2Si2 tetrahedra,  a cornercorner with one N(7)Sm2Si2 tetrahedra,  a cornercorner with one N(9)Sm2Si2 tetrahedra,  a cornercorner with one N(19)SmSi3 tetrahedra,  a cornercorner with one N(20)SmSi3 tetrahedra, and corners with two equivalent N(1)Sm3AlSi trigonal bipyramids. In the thirteenth N site, N(13) is bonded in a 3-coordinate geometry to one Ba(1), one Sm(3), one Si(1), and one Si(9) atom. In the fourteenth N site, N(14) is bonded in a 3-coordinate geometry to one Ba(1), one Sm(4), one Si(2), and one Si(8) atom. In the fifteenth N site, N(15) is bonded in a 3-coordinate geometry to one Ba(1), one Sm(5), one Al(3), and one Si(3) atom. In the sixteenth N site, N(16) is bonded in a 3-coordinate geometry to one Ba(1), one Sm(5), one Al(2), and one Si(4) atom. In the seventeenth N site, N(17) is bonded in a 3-coordinate geometry to one Ba(1), one Sm(3), one Si(5), and one Si(7) atom. In the eighteenth N site, N(18) is bonded in a 3-coordinate geometry to one Ba(1), one Sm(4), one Al(1), and one Si(6) atom. In the nineteenth N site, N(19) is bonded to one Sm(1), one Si(1), one Si(2), and one Si(3) atom to form distorted NSmSi3 tetrahedra that share  a cornercorner with one N(10)AlSi3 tetrahedra,  a cornercorner with one N(11)AlSi3 tetrahedra,  a cornercorner with one N(12)AlSi3 tetrahedra, corners with two equivalent N(4)Sm2AlSi tetrahedra, corners with two equivalent N(5)Sm2AlSi tetrahedra, corners with two equivalent N(6)Sm2Si2 tetrahedra,  a cornercorner with one N(1)Sm3AlSi trigonal bipyramid,  a cornercorner with one N(2)Sm3AlSi trigonal bipyramid, and  a cornercorner with one N(3)Sm3AlSi trigonal bipyramid. In the twentieth N site, N(20) is bonded to one Sm(2), one Si(4), one Si(5), and one Si(6) atom to form distorted NSmSi3 tetrahedra that share  a cornercorner with one N(10)AlSi3 tetrahedra,  a cornercorner with one N(11)AlSi3 tetrahedra,  a cornercorner with one N(12)AlSi3 tetrahedra, corners with two equivalent N(8)Sm2AlSi tetrahedra, corners with two equivalent N(7)Sm2Si2 tetrahedra, corners with two equivalent N(9)Sm2Si2 tetrahedra,  a cornercorner with one N(1)Sm3AlSi trigonal bipyramid,  a cornercorner with one N(2)Sm3AlSi trigonal bipyramid, and  a cornercorner with one N(3)Sm3AlSi trigonal bipyramid. O(1) is bonded to two equivalent Ba(1), one Sm(3), one Sm(4), and one Sm(5) atom to form OBa2Sm3 trigonal bipyramids that share  a cornercorner with one N(4)Sm2AlSi tetrahedra,  a cornercorner with one N(5)Sm2AlSi tetrahedra,  a cornercorner with one N(8)Sm2AlSi tetrahedra,  a cornercorner with one N(6)Sm2Si2 tetrahedra,  a cornercorner with one N(7)Sm2Si2 tetrahedra,  a cornercorner with one N(9)Sm2Si2 tetrahedra,  a cornercorner with one N(1)Sm3AlSi trigonal bipyramid,  a cornercorner with one N(2)Sm3AlSi trigonal bipyramid,  a cornercorner with one N(3)Sm3AlSi trigonal bipyramid, and corners with two equivalent O(1)Ba2Sm3 trigonal bipyramids.