EuHo2Se4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to one Se(1), two equivalent Se(3), and three equivalent Se(2) atoms to form a mixture of corner and edge-sharing HoSe6 octahedra. The corner-sharing octahedral tilt angles range from 47-64°. In the second Ho site, Ho(2) is bonded to one Se(3), two equivalent Se(1), and three equivalent Se(4) atoms to form a mixture of corner and edge-sharing HoSe6 octahedra. The corner-sharing octahedral tilt angles range from 47-64°. Eu(1) is bonded in a 8-coordinate geometry to two equivalent Se(1), two equivalent Se(2), two equivalent Se(3), and two equivalent Se(4) atoms. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to one Ho(1), two equivalent Ho(2), and two equivalent Eu(1) atoms to form a mixture of distorted corner and edge-sharing SeEu2Ho3 trigonal bipyramids. In the second Se site, Se(2) is bonded to three equivalent Ho(1) and two equivalent Eu(1) atoms to form a mixture of corner and edge-sharing SeEu2Ho3 square pyramids. In the third Se site, Se(3) is bonded to one Ho(2), two equivalent Ho(1), and two equivalent Eu(1) atoms to form a mixture of distorted corner and edge-sharing SeEu2Ho3 trigonal bipyramids. In the fourth Se site, Se(4) is bonded to three equivalent Ho(2) and two equivalent Eu(1) atoms to form a mixture of distorted corner and edge-sharing SeEu2Ho3 trigonal bipyramids.
EuHo2Se4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to one Se(1), two equivalent Se(3), and three equivalent Se(2) atoms to form a mixture of corner and edge-sharing HoSe6 octahedra. The corner-sharing octahedral tilt angles range from 47-64°. The Ho(1)-Se(1) bond length is 2.88 Å. Both Ho(1)-Se(3) bond lengths are 2.79 Å. There is one shorter (2.86 Å) and two longer (2.87 Å) Ho(1)-Se(2) bond lengths. In the second Ho site, Ho(2) is bonded to one Se(3), two equivalent Se(1), and three equivalent Se(4) atoms to form a mixture of corner and edge-sharing HoSe6 octahedra. The corner-sharing octahedral tilt angles range from 47-64°. The Ho(2)-Se(3) bond length is 2.82 Å. Both Ho(2)-Se(1) bond lengths are 2.88 Å. There is one shorter (2.83 Å) and two longer (2.86 Å) Ho(2)-Se(4) bond lengths. Eu(1) is bonded in a 8-coordinate geometry to two equivalent Se(1), two equivalent Se(2), two equivalent Se(3), and two equivalent Se(4) atoms. Both Eu(1)-Se(1) bond lengths are 3.18 Å. Both Eu(1)-Se(2) bond lengths are 3.18 Å. Both Eu(1)-Se(3) bond lengths are 3.42 Å. Both Eu(1)-Se(4) bond lengths are 3.21 Å. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to one Ho(1), two equivalent Ho(2), and two equivalent Eu(1) atoms to form a mixture of distorted corner and edge-sharing SeEu2Ho3 trigonal bipyramids. In the second Se site, Se(2) is bonded to three equivalent Ho(1) and two equivalent Eu(1) atoms to form a mixture of corner and edge-sharing SeEu2Ho3 square pyramids. In the third Se site, Se(3) is bonded to one Ho(2), two equivalent Ho(1), and two equivalent Eu(1) atoms to form a mixture of distorted corner and edge-sharing SeEu2Ho3 trigonal bipyramids. In the fourth Se site, Se(4) is bonded to three equivalent Ho(2) and two equivalent Eu(1) atoms to form a mixture of distorted corner and edge-sharing SeEu2Ho3 trigonal bipyramids.