BaSrYb4O8 crystallizes in the orthorhombic Pmc2_1 space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), two equivalent O(6), and two equivalent O(7) atoms. Sr(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(5), and two equivalent O(8) atoms. There are four inequivalent Yb sites. In the first Yb site, Yb(1) is bonded to one O(1), one O(7), two equivalent O(2), and two equivalent O(6) atoms to form a mixture of distorted edge and corner-sharing YbO6 octahedra. The corner-sharing octahedral tilt angles range from 48-65°. In the second Yb site, Yb(2) is bonded to one O(2), one O(8), two equivalent O(1), and two equivalent O(5) atoms to form a mixture of distorted edge and corner-sharing YbO6 octahedra. The corner-sharing octahedral tilt angles range from 50-65°. In the third Yb site, Yb(3) is bonded to one O(3), one O(5), two equivalent O(4), and two equivalent O(8) atoms to form a mixture of edge and corner-sharing YbO6 octahedra. The corner-sharing octahedral tilt angles range from 50-65°. In the fourth Yb site, Yb(4) is bonded to one O(4), one O(6), two equivalent O(3), and two equivalent O(7) atoms to form a mixture of edge and corner-sharing YbO6 octahedra. The corner-sharing octahedral tilt angles range from 48-65°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), one Yb(1), and two equivalent Yb(2) atoms to form distorted OSr2Yb3 trigonal bipyramids that share corners with two equivalent O(3)Sr2Yb3 square pyramids,  a cornercorner with one O(7)Ba2Yb3 trigonal bipyramid, corners with two equivalent O(8)Sr2Yb3 trigonal bipyramids, corners with four equivalent O(5)Sr2Yb3 trigonal bipyramids,  an edgeedge with one O(3)Sr2Yb3 square pyramid, edges with two equivalent O(2)Ba2Yb3 trigonal bipyramids, edges with two equivalent O(1)Sr2Yb3 trigonal bipyramids, edges with two equivalent O(5)Sr2Yb3 trigonal bipyramids, and edges with two equivalent O(8)Sr2Yb3 trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Ba(1), one Yb(2), and two equivalent Yb(1) atoms to form distorted OBa2Yb3 trigonal bipyramids that share corners with two equivalent O(4)Ba2Yb3 square pyramids,  a cornercorner with one O(8)Sr2Yb3 trigonal bipyramid, corners with two equivalent O(7)Ba2Yb3 trigonal bipyramids, corners with two equivalent O(5)Sr2Yb3 trigonal bipyramids,  an edgeedge with one O(4)Ba2Yb3 square pyramid, edges with two equivalent O(2)Ba2Yb3 trigonal bipyramids, edges with two equivalent O(7)Ba2Yb3 trigonal bipyramids, and edges with two equivalent O(1)Sr2Yb3 trigonal bipyramids. In the third O site, O(3) is bonded to two equivalent Sr(1), one Yb(3), and two equivalent Yb(4) atoms to form OSr2Yb3 square pyramids that share corners with two equivalent O(7)Ba2Yb3 trigonal bipyramids, corners with two equivalent O(1)Sr2Yb3 trigonal bipyramids, corners with two equivalent O(8)Sr2Yb3 trigonal bipyramids, corners with three equivalent O(5)Sr2Yb3 trigonal bipyramids, edges with two equivalent O(4)Ba2Yb3 square pyramids, edges with two equivalent O(3)Sr2Yb3 square pyramids,  an edgeedge with one O(7)Ba2Yb3 trigonal bipyramid,  an edgeedge with one O(1)Sr2Yb3 trigonal bipyramid,  an edgeedge with one O(5)Sr2Yb3 trigonal bipyramid, and edges with two equivalent O(8)Sr2Yb3 trigonal bipyramids. In the fourth O site, O(4) is bonded to two equivalent Ba(1), one Yb(4), and two equivalent Yb(3) atoms to form distorted OBa2Yb3 square pyramids that share corners with two equivalent O(2)Ba2Yb3 trigonal bipyramids, corners with two equivalent O(7)Ba2Yb3 trigonal bipyramids, corners with two equivalent O(5)Sr2Yb3 trigonal bipyramids, corners with two equivalent O(8)Sr2Yb3 trigonal bipyramids, edges with two equivalent O(4)Ba2Yb3 square pyramids, edges with two equivalent O(3)Sr2Yb3 square pyramids,  an edgeedge with one O(2)Ba2Yb3 trigonal bipyramid,  an edgeedge with one O(8)Sr2Yb3 trigonal bipyramid, and edges with two equivalent O(7)Ba2Yb3 trigonal bipyramids. In the fifth O site, O(5) is bonded to two equivalent Sr(1), one Yb(3), and two equivalent Yb(2) atoms to form distorted OSr2Yb3 trigonal bipyramids that share corners with two equivalent O(4)Ba2Yb3 square pyramids, corners with three equivalent O(3)Sr2Yb3 square pyramids, corners with two equivalent O(2)Ba2Yb3 trigonal bipyramids, corners with four equivalent O(1)Sr2Yb3 trigonal bipyramids,  an edgeedge with one O(3)Sr2Yb3 square pyramid, edges with two equivalent O(1)Sr2Yb3 trigonal bipyramids, edges with two equivalent O(5)Sr2Yb3 trigonal bipyramids, and edges with four equivalent O(8)Sr2Yb3 trigonal bipyramids. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to two equivalent Ba(1), one Yb(4), and two equivalent Yb(1) atoms. In the seventh O site, O(7) is bonded to two equivalent Ba(1), one Yb(1), and two equivalent Yb(4) atoms to form distorted OBa2Yb3 trigonal bipyramids that share corners with two equivalent O(4)Ba2Yb3 square pyramids, corners with two equivalent O(3)Sr2Yb3 square pyramids,  a cornercorner with one O(1)Sr2Yb3 trigonal bipyramid, corners with two equivalent O(2)Ba2Yb3 trigonal bipyramids, corners with four equivalent O(7)Ba2Yb3 trigonal bipyramids,  an edgeedge with one O(3)Sr2Yb3 square pyramid, edges with two equivalent O(4)Ba2Yb3 square pyramids, and edges with two equivalent O(2)Ba2Yb3 trigonal bipyramids. In the eighth O site, O(8) is bonded to two equivalent Sr(1), one Yb(2), and two equivalent Yb(3) atoms to form distorted OSr2Yb3 trigonal bipyramids that share corners with two equivalent O(4)Ba2Yb3 square pyramids, corners with two equivalent O(3)Sr2Yb3 square pyramids,  a cornercorner with one O(2)Ba2Yb3 trigonal bipyramid, corners with two equivalent O(1)Sr2Yb3 trigonal bipyramids, corners with four equivalent O(8)Sr2Yb3 trigonal bipyramids,  an edgeedge with one O(4)Ba2Yb3 square pyramid, edges with two equivalent O(3)Sr2Yb3 square pyramids, edges with two equivalent O(1)Sr2Yb3 trigonal bipyramids, and edges with four equivalent O(5)Sr2Yb3 trigonal bipyramids.
BaSrYb4O8 crystallizes in the orthorhombic Pmc2_1 space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), two equivalent O(6), and two equivalent O(7) atoms. Both Ba(1)-O(2) bond lengths are 2.71 Å. Both Ba(1)-O(4) bond lengths are 2.75 Å. Both Ba(1)-O(6) bond lengths are 2.79 Å. There is one shorter (2.78 Å) and one longer (2.80 Å) Ba(1)-O(7) bond length. Sr(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(5), and two equivalent O(8) atoms. Both Sr(1)-O(1) bond lengths are 2.60 Å. Both Sr(1)-O(3) bond lengths are 2.65 Å. Both Sr(1)-O(5) bond lengths are 2.65 Å. There is one shorter (2.71 Å) and one longer (2.83 Å) Sr(1)-O(8) bond length. There are four inequivalent Yb sites. In the first Yb site, Yb(1) is bonded to one O(1), one O(7), two equivalent O(2), and two equivalent O(6) atoms to form a mixture of distorted edge and corner-sharing YbO6 octahedra. The corner-sharing octahedral tilt angles range from 48-65°. The Yb(1)-O(1) bond length is 2.29 Å. The Yb(1)-O(7) bond length is 2.33 Å. Both Yb(1)-O(2) bond lengths are 2.35 Å. Both Yb(1)-O(6) bond lengths are 2.33 Å. In the second Yb site, Yb(2) is bonded to one O(2), one O(8), two equivalent O(1), and two equivalent O(5) atoms to form a mixture of distorted edge and corner-sharing YbO6 octahedra. The corner-sharing octahedral tilt angles range from 50-65°. The Yb(2)-O(2) bond length is 2.24 Å. The Yb(2)-O(8) bond length is 2.22 Å. Both Yb(2)-O(1) bond lengths are 2.39 Å. Both Yb(2)-O(5) bond lengths are 2.37 Å. In the third Yb site, Yb(3) is bonded to one O(3), one O(5), two equivalent O(4), and two equivalent O(8) atoms to form a mixture of edge and corner-sharing YbO6 octahedra. The corner-sharing octahedral tilt angles range from 50-65°. The Yb(3)-O(3) bond length is 2.32 Å. The Yb(3)-O(5) bond length is 2.27 Å. Both Yb(3)-O(4) bond lengths are 2.36 Å. Both Yb(3)-O(8) bond lengths are 2.28 Å. In the fourth Yb site, Yb(4) is bonded to one O(4), one O(6), two equivalent O(3), and two equivalent O(7) atoms to form a mixture of edge and corner-sharing YbO6 octahedra. The corner-sharing octahedral tilt angles range from 48-65°. The Yb(4)-O(4) bond length is 2.27 Å. The Yb(4)-O(6) bond length is 2.22 Å. Both Yb(4)-O(3) bond lengths are 2.39 Å. Both Yb(4)-O(7) bond lengths are 2.35 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), one Yb(1), and two equivalent Yb(2) atoms to form distorted OSr2Yb3 trigonal bipyramids that share corners with two equivalent O(3)Sr2Yb3 square pyramids,  a cornercorner with one O(7)Ba2Yb3 trigonal bipyramid, corners with two equivalent O(8)Sr2Yb3 trigonal bipyramids, corners with four equivalent O(5)Sr2Yb3 trigonal bipyramids,  an edgeedge with one O(3)Sr2Yb3 square pyramid, edges with two equivalent O(2)Ba2Yb3 trigonal bipyramids, edges with two equivalent O(1)Sr2Yb3 trigonal bipyramids, edges with two equivalent O(5)Sr2Yb3 trigonal bipyramids, and edges with two equivalent O(8)Sr2Yb3 trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Ba(1), one Yb(2), and two equivalent Yb(1) atoms to form distorted OBa2Yb3 trigonal bipyramids that share corners with two equivalent O(4)Ba2Yb3 square pyramids,  a cornercorner with one O(8)Sr2Yb3 trigonal bipyramid, corners with two equivalent O(7)Ba2Yb3 trigonal bipyramids, corners with two equivalent O(5)Sr2Yb3 trigonal bipyramids,  an edgeedge with one O(4)Ba2Yb3 square pyramid, edges with two equivalent O(2)Ba2Yb3 trigonal bipyramids, edges with two equivalent O(7)Ba2Yb3 trigonal bipyramids, and edges with two equivalent O(1)Sr2Yb3 trigonal bipyramids. In the third O site, O(3) is bonded to two equivalent Sr(1), one Yb(3), and two equivalent Yb(4) atoms to form OSr2Yb3 square pyramids that share corners with two equivalent O(7)Ba2Yb3 trigonal bipyramids, corners with two equivalent O(1)Sr2Yb3 trigonal bipyramids, corners with two equivalent O(8)Sr2Yb3 trigonal bipyramids, corners with three equivalent O(5)Sr2Yb3 trigonal bipyramids, edges with two equivalent O(4)Ba2Yb3 square pyramids, edges with two equivalent O(3)Sr2Yb3 square pyramids,  an edgeedge with one O(7)Ba2Yb3 trigonal bipyramid,  an edgeedge with one O(1)Sr2Yb3 trigonal bipyramid,  an edgeedge with one O(5)Sr2Yb3 trigonal bipyramid, and edges with two equivalent O(8)Sr2Yb3 trigonal bipyramids. In the fourth O site, O(4) is bonded to two equivalent Ba(1), one Yb(4), and two equivalent Yb(3) atoms to form distorted OBa2Yb3 square pyramids that share corners with two equivalent O(2)Ba2Yb3 trigonal bipyramids, corners with two equivalent O(7)Ba2Yb3 trigonal bipyramids, corners with two equivalent O(5)Sr2Yb3 trigonal bipyramids, corners with two equivalent O(8)Sr2Yb3 trigonal bipyramids, edges with two equivalent O(4)Ba2Yb3 square pyramids, edges with two equivalent O(3)Sr2Yb3 square pyramids,  an edgeedge with one O(2)Ba2Yb3 trigonal bipyramid,  an edgeedge with one O(8)Sr2Yb3 trigonal bipyramid, and edges with two equivalent O(7)Ba2Yb3 trigonal bipyramids. In the fifth O site, O(5) is bonded to two equivalent Sr(1), one Yb(3), and two equivalent Yb(2) atoms to form distorted OSr2Yb3 trigonal bipyramids that share corners with two equivalent O(4)Ba2Yb3 square pyramids, corners with three equivalent O(3)Sr2Yb3 square pyramids, corners with two equivalent O(2)Ba2Yb3 trigonal bipyramids, corners with four equivalent O(1)Sr2Yb3 trigonal bipyramids,  an edgeedge with one O(3)Sr2Yb3 square pyramid, edges with two equivalent O(1)Sr2Yb3 trigonal bipyramids, edges with two equivalent O(5)Sr2Yb3 trigonal bipyramids, and edges with four equivalent O(8)Sr2Yb3 trigonal bipyramids. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to two equivalent Ba(1), one Yb(4), and two equivalent Yb(1) atoms. In the seventh O site, O(7) is bonded to two equivalent Ba(1), one Yb(1), and two equivalent Yb(4) atoms to form distorted OBa2Yb3 trigonal bipyramids that share corners with two equivalent O(4)Ba2Yb3 square pyramids, corners with two equivalent O(3)Sr2Yb3 square pyramids,  a cornercorner with one O(1)Sr2Yb3 trigonal bipyramid, corners with two equivalent O(2)Ba2Yb3 trigonal bipyramids, corners with four equivalent O(7)Ba2Yb3 trigonal bipyramids,  an edgeedge with one O(3)Sr2Yb3 square pyramid, edges with two equivalent O(4)Ba2Yb3 square pyramids, and edges with two equivalent O(2)Ba2Yb3 trigonal bipyramids. In the eighth O site, O(8) is bonded to two equivalent Sr(1), one Yb(2), and two equivalent Yb(3) atoms to form distorted OSr2Yb3 trigonal bipyramids that share corners with two equivalent O(4)Ba2Yb3 square pyramids, corners with two equivalent O(3)Sr2Yb3 square pyramids,  a cornercorner with one O(2)Ba2Yb3 trigonal bipyramid, corners with two equivalent O(1)Sr2Yb3 trigonal bipyramids, corners with four equivalent O(8)Sr2Yb3 trigonal bipyramids,  an edgeedge with one O(4)Ba2Yb3 square pyramid, edges with two equivalent O(3)Sr2Yb3 square pyramids, edges with two equivalent O(1)Sr2Yb3 trigonal bipyramids, and edges with four equivalent O(5)Sr2Yb3 trigonal bipyramids.