ErTiO3Cl crystallizes in the monoclinic C2/m space group. Er(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), two equivalent O(1), and four equivalent Cl(1) atoms. Ti(1) is bonded to one O(1), two equivalent O(3), and three equivalent O(2) atoms to form a mixture of distorted edge and corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 27°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to two equivalent Er(1) and one Ti(1) atom. In the second O site, O(2) is bonded to one Er(1) and three equivalent Ti(1) atoms to form distorted OErTi3 trigonal pyramids that share corners with four equivalent Cl(1)Er4 tetrahedra, corners with two equivalent O(2)ErTi3 trigonal pyramids, and edges with two equivalent O(2)ErTi3 trigonal pyramids. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Er(1) and two equivalent Ti(1) atoms. Cl(1) is bonded to four equivalent Er(1) atoms to form distorted ClEr4 tetrahedra that share corners with six equivalent Cl(1)Er4 tetrahedra, corners with four equivalent O(2)ErTi3 trigonal pyramids, and edges with three equivalent Cl(1)Er4 tetrahedra.
ErTiO3Cl crystallizes in the monoclinic C2/m space group. Er(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), two equivalent O(1), and four equivalent Cl(1) atoms. The Er(1)-O(2) bond length is 2.47 Å. The Er(1)-O(3) bond length is 2.17 Å. Both Er(1)-O(1) bond lengths are 2.16 Å. There are a spread of Er(1)-Cl(1) bond distances ranging from 2.85-3.17 Å. Ti(1) is bonded to one O(1), two equivalent O(3), and three equivalent O(2) atoms to form a mixture of distorted edge and corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 27°. The Ti(1)-O(1) bond length is 1.87 Å. There is one shorter (1.86 Å) and one longer (2.07 Å) Ti(1)-O(3) bond length. There are two shorter (2.01 Å) and one longer (2.14 Å) Ti(1)-O(2) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to two equivalent Er(1) and one Ti(1) atom. In the second O site, O(2) is bonded to one Er(1) and three equivalent Ti(1) atoms to form distorted OErTi3 trigonal pyramids that share corners with four equivalent Cl(1)Er4 tetrahedra, corners with two equivalent O(2)ErTi3 trigonal pyramids, and edges with two equivalent O(2)ErTi3 trigonal pyramids. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Er(1) and two equivalent Ti(1) atoms. Cl(1) is bonded to four equivalent Er(1) atoms to form distorted ClEr4 tetrahedra that share corners with six equivalent Cl(1)Er4 tetrahedra, corners with four equivalent O(2)ErTi3 trigonal pyramids, and edges with three equivalent Cl(1)Er4 tetrahedra.