Ca2YBiO5 is Aluminum carbonitride-derived structured and crystallizes in the monoclinic Cc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(5) atoms to form distorted CaO5 square pyramids that share corners with two equivalent Bi(1)O6 octahedra,  a cornercorner with one Ca(2)O5 square pyramid, corners with four equivalent Ca(1)O5 square pyramids, corners with four equivalent Y(1)O4 tetrahedra, and edges with two equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 67-85°. In the second Ca site, Ca(2) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted CaO5 square pyramids that share corners with two equivalent Bi(1)O6 octahedra,  a cornercorner with one Ca(1)O5 square pyramid, corners with four equivalent Ca(2)O5 square pyramids, corners with four equivalent Y(1)O4 tetrahedra, and edges with two equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 65-83°. Y(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form distorted YO4 tetrahedra that share corners with two equivalent Bi(1)O6 octahedra, corners with four equivalent Ca(1)O5 square pyramids, corners with four equivalent Ca(2)O5 square pyramids, and corners with two equivalent Y(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 66-67°. Bi(1) is bonded to one O(2), one O(3), two equivalent O(4), and two equivalent O(5) atoms to form distorted BiO6 octahedra that share corners with four equivalent Bi(1)O6 octahedra, corners with two equivalent Ca(1)O5 square pyramids, corners with two equivalent Ca(2)O5 square pyramids, corners with two equivalent Y(1)O4 tetrahedra, edges with two equivalent Ca(1)O5 square pyramids, and edges with two equivalent Ca(2)O5 square pyramids. The corner-sharing octahedral tilt angles range from 47-50°. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Ca(2), and two equivalent Y(1) atoms to form OCa2Y2 tetrahedra that share corners with two equivalent O(1)Ca2Y2 tetrahedra, corners with four equivalent O(2)Ca2YBi tetrahedra, corners with four equivalent O(3)Ca2YBi tetrahedra, corners with two equivalent O(4)Ca2Bi2 trigonal pyramids, and corners with two equivalent O(5)Ca2Bi2 trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Ca(1), one Y(1), and one Bi(1) atom to form distorted OCa2YBi tetrahedra that share corners with two equivalent O(2)Ca2YBi tetrahedra, corners with two equivalent O(3)Ca2YBi tetrahedra, corners with four equivalent O(1)Ca2Y2 tetrahedra, corners with two equivalent O(4)Ca2Bi2 trigonal pyramids, corners with four equivalent O(5)Ca2Bi2 trigonal pyramids, and  an edgeedge with one O(5)Ca2Bi2 trigonal pyramid. In the third O site, O(3) is bonded to two equivalent Ca(2), one Y(1), and one Bi(1) atom to form distorted OCa2YBi tetrahedra that share corners with two equivalent O(2)Ca2YBi tetrahedra, corners with two equivalent O(3)Ca2YBi tetrahedra, corners with four equivalent O(1)Ca2Y2 tetrahedra, corners with two equivalent O(5)Ca2Bi2 trigonal pyramids, corners with four equivalent O(4)Ca2Bi2 trigonal pyramids, and  an edgeedge with one O(4)Ca2Bi2 trigonal pyramid. In the fourth O site, O(4) is bonded to two equivalent Ca(2) and two equivalent Bi(1) atoms to form distorted OCa2Bi2 trigonal pyramids that share corners with two equivalent O(1)Ca2Y2 tetrahedra, corners with two equivalent O(2)Ca2YBi tetrahedra, corners with four equivalent O(3)Ca2YBi tetrahedra, corners with four equivalent O(5)Ca2Bi2 trigonal pyramids,  an edgeedge with one O(3)Ca2YBi tetrahedra, and edges with two equivalent O(4)Ca2Bi2 trigonal pyramids. In the fifth O site, O(5) is bonded to two equivalent Ca(1) and two equivalent Bi(1) atoms to form distorted OCa2Bi2 trigonal pyramids that share corners with two equivalent O(1)Ca2Y2 tetrahedra, corners with two equivalent O(3)Ca2YBi tetrahedra, corners with four equivalent O(2)Ca2YBi tetrahedra, corners with four equivalent O(4)Ca2Bi2 trigonal pyramids,  an edgeedge with one O(2)Ca2YBi tetrahedra, and edges with two equivalent O(5)Ca2Bi2 trigonal pyramids.
Ca2YBiO5 is Aluminum carbonitride-derived structured and crystallizes in the monoclinic Cc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(5) atoms to form distorted CaO5 square pyramids that share corners with two equivalent Bi(1)O6 octahedra,  a cornercorner with one Ca(2)O5 square pyramid, corners with four equivalent Ca(1)O5 square pyramids, corners with four equivalent Y(1)O4 tetrahedra, and edges with two equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 67-85°. The Ca(1)-O(1) bond length is 2.28 Å. There is one shorter (2.33 Å) and one longer (2.40 Å) Ca(1)-O(2) bond length. Both Ca(1)-O(5) bond lengths are 2.40 Å. In the second Ca site, Ca(2) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted CaO5 square pyramids that share corners with two equivalent Bi(1)O6 octahedra,  a cornercorner with one Ca(1)O5 square pyramid, corners with four equivalent Ca(2)O5 square pyramids, corners with four equivalent Y(1)O4 tetrahedra, and edges with two equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 65-83°. The Ca(2)-O(1) bond length is 2.31 Å. There is one shorter (2.32 Å) and one longer (2.41 Å) Ca(2)-O(3) bond length. There is one shorter (2.35 Å) and one longer (2.38 Å) Ca(2)-O(4) bond length. Y(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form distorted YO4 tetrahedra that share corners with two equivalent Bi(1)O6 octahedra, corners with four equivalent Ca(1)O5 square pyramids, corners with four equivalent Ca(2)O5 square pyramids, and corners with two equivalent Y(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 66-67°. The Y(1)-O(2) bond length is 2.18 Å. The Y(1)-O(3) bond length is 2.18 Å. There is one shorter (2.22 Å) and one longer (2.31 Å) Y(1)-O(1) bond length. Bi(1) is bonded to one O(2), one O(3), two equivalent O(4), and two equivalent O(5) atoms to form distorted BiO6 octahedra that share corners with four equivalent Bi(1)O6 octahedra, corners with two equivalent Ca(1)O5 square pyramids, corners with two equivalent Ca(2)O5 square pyramids, corners with two equivalent Y(1)O4 tetrahedra, edges with two equivalent Ca(1)O5 square pyramids, and edges with two equivalent Ca(2)O5 square pyramids. The corner-sharing octahedral tilt angles range from 47-50°. The Bi(1)-O(2) bond length is 2.57 Å. The Bi(1)-O(3) bond length is 2.50 Å. There is one shorter (2.21 Å) and one longer (2.52 Å) Bi(1)-O(4) bond length. There is one shorter (2.19 Å) and one longer (2.50 Å) Bi(1)-O(5) bond length. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Ca(2), and two equivalent Y(1) atoms to form OCa2Y2 tetrahedra that share corners with two equivalent O(1)Ca2Y2 tetrahedra, corners with four equivalent O(2)Ca2YBi tetrahedra, corners with four equivalent O(3)Ca2YBi tetrahedra, corners with two equivalent O(4)Ca2Bi2 trigonal pyramids, and corners with two equivalent O(5)Ca2Bi2 trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Ca(1), one Y(1), and one Bi(1) atom to form distorted OCa2YBi tetrahedra that share corners with two equivalent O(2)Ca2YBi tetrahedra, corners with two equivalent O(3)Ca2YBi tetrahedra, corners with four equivalent O(1)Ca2Y2 tetrahedra, corners with two equivalent O(4)Ca2Bi2 trigonal pyramids, corners with four equivalent O(5)Ca2Bi2 trigonal pyramids, and  an edgeedge with one O(5)Ca2Bi2 trigonal pyramid. In the third O site, O(3) is bonded to two equivalent Ca(2), one Y(1), and one Bi(1) atom to form distorted OCa2YBi tetrahedra that share corners with two equivalent O(2)Ca2YBi tetrahedra, corners with two equivalent O(3)Ca2YBi tetrahedra, corners with four equivalent O(1)Ca2Y2 tetrahedra, corners with two equivalent O(5)Ca2Bi2 trigonal pyramids, corners with four equivalent O(4)Ca2Bi2 trigonal pyramids, and  an edgeedge with one O(4)Ca2Bi2 trigonal pyramid. In the fourth O site, O(4) is bonded to two equivalent Ca(2) and two equivalent Bi(1) atoms to form distorted OCa2Bi2 trigonal pyramids that share corners with two equivalent O(1)Ca2Y2 tetrahedra, corners with two equivalent O(2)Ca2YBi tetrahedra, corners with four equivalent O(3)Ca2YBi tetrahedra, corners with four equivalent O(5)Ca2Bi2 trigonal pyramids,  an edgeedge with one O(3)Ca2YBi tetrahedra, and edges with two equivalent O(4)Ca2Bi2 trigonal pyramids. In the fifth O site, O(5) is bonded to two equivalent Ca(1) and two equivalent Bi(1) atoms to form distorted OCa2Bi2 trigonal pyramids that share corners with two equivalent O(1)Ca2Y2 tetrahedra, corners with two equivalent O(3)Ca2YBi tetrahedra, corners with four equivalent O(2)Ca2YBi tetrahedra, corners with four equivalent O(4)Ca2Bi2 trigonal pyramids,  an edgeedge with one O(2)Ca2YBi tetrahedra, and edges with two equivalent O(5)Ca2Bi2 trigonal pyramids.