The compound described by Ba5Yb8Ni4O21 crystallizes in the tetragonal I4/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(4), four equivalent O(2), and four equivalent O(3) atoms. In the second Ba site, Ba(2) is bonded in a distorted q6 geometry to two equivalent O(1) and eight equivalent O(4) atoms. There are two inequivalent Yb sites. In the first Yb site, Yb(1) is bonded to one O(2), two equivalent O(4), and four equivalent O(3) atoms to form distorted YbO7 pentagonal bipyramids that share corners with two equivalent Yb(2)O7 pentagonal bipyramids, corners with two equivalent Ni(1)O5 square pyramids, edges with two equivalent Yb(1)O7 pentagonal bipyramids, edges with three equivalent Yb(2)O7 pentagonal bipyramids,  an edgeedge with one Ni(1)O5 square pyramid, and  a faceface with one Ni(1)O5 square pyramid. In the second Yb site, Yb(2) is bonded to one O(1), two equivalent O(3), and four equivalent O(4) atoms to form distorted YbO7 pentagonal bipyramids that share  a cornercorner with one Yb(2)O7 pentagonal bipyramid, corners with two equivalent Yb(1)O7 pentagonal bipyramids, corners with two equivalent Ni(1)O5 square pyramids, edges with three equivalent Yb(1)O7 pentagonal bipyramids, edges with two equivalent Ni(1)O5 square pyramids, and faces with two equivalent Yb(2)O7 pentagonal bipyramids. Ni(1) is bonded to one O(2), two equivalent O(3), and two equivalent O(4) atoms to form NiO5 square pyramids that share corners with two equivalent Yb(1)O7 pentagonal bipyramids, corners with two equivalent Yb(2)O7 pentagonal bipyramids,  an edgeedge with one Yb(1)O7 pentagonal bipyramid, edges with two equivalent Yb(2)O7 pentagonal bipyramids, and  a faceface with one Yb(1)O7 pentagonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ba(2) and four equivalent Yb(2) atoms to form OBa2Yb4 octahedra that share corners with two equivalent O(1)Ba2Yb4 octahedra, corners with eight equivalent O(4)Ba2Yb3Ni octahedra, and faces with eight equivalent O(4)Ba2Yb3Ni octahedra. The corner-sharing octahedral tilt angles range from 0-63°. In the second O site, O(2) is bonded to four equivalent Ba(1), one Yb(1), and one Ni(1) atom to form distorted OBa4YbNi octahedra that share corners with two equivalent O(2)Ba4YbNi octahedra, corners with six equivalent O(4)Ba2Yb3Ni octahedra, edges with five equivalent O(2)Ba4YbNi octahedra, and faces with two equivalent O(4)Ba2Yb3Ni octahedra. The corner-sharing octahedral tilt angles range from 6-59°. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Ba(1), one Yb(2), two equivalent Yb(1), and one Ni(1) atom. In the fourth O site, O(4) is bonded to one Ba(1), one Ba(2), one Yb(1), two equivalent Yb(2), and one Ni(1) atom to form distorted OBa2Yb3Ni octahedra that share  a cornercorner with one O(1)Ba2Yb4 octahedra, corners with three equivalent O(2)Ba4YbNi octahedra, corners with six equivalent O(4)Ba2Yb3Ni octahedra, edges with two equivalent O(4)Ba2Yb3Ni octahedra,  a faceface with one O(1)Ba2Yb4 octahedra,  a faceface with one O(2)Ba4YbNi octahedra, and faces with two equivalent O(4)Ba2Yb3Ni octahedra. The corner-sharing octahedral tilt angles range from 0-78°. is represented by the CIF card [CIF]
data_Ba5Yb8Ni4O21
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.970
_cell_length_b   9.970
_cell_length_c   9.970
_cell_angle_alpha   94.619
_cell_angle_beta   94.619
_cell_angle_gamma   147.028
_symmetry_Int_Tables_number   1
_cell_volume   517.200
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ba  Ba0  1  0.532  0.853  0.385  1.0
  Ba  Ba1  1  0.853  0.468  0.321  1.0
  Ba  Ba2  1  0.147  0.532  0.679  1.0
  Ba  Ba3  1  0.468  0.147  0.615  1.0
  Ba  Ba4  1  0.000  0.000  0.000  1.0
  Yb  Yb5  1  0.830  0.750  0.580  1.0
  Yb  Yb6  1  0.750  0.170  0.919  1.0
  Yb  Yb7  1  0.250  0.830  0.081  1.0
  Yb  Yb8  1  0.170  0.250  0.420  1.0
  Yb  Yb9  1  0.639  0.593  0.232  1.0
  Yb  Yb10  1  0.593  0.361  0.954  1.0
  Yb  Yb11  1  0.407  0.639  0.046  1.0
  Yb  Yb12  1  0.361  0.407  0.768  1.0
  Ni  Ni13  1  0.757  0.959  0.715  1.0
  Ni  Ni14  1  0.959  0.243  0.202  1.0
  Ni  Ni15  1  0.041  0.757  0.798  1.0
  Ni  Ni16  1  0.243  0.041  0.285  1.0
  O  O17  1  0.500  0.500  0.000  1.0
  O  O18  1  0.975  0.639  0.613  1.0
  O  O19  1  0.639  0.025  0.664  1.0
  O  O20  1  0.361  0.975  0.336  1.0
  O  O21  1  0.025  0.361  0.387  1.0
  O  O22  1  0.503  0.633  0.595  1.0
  O  O23  1  0.633  0.038  0.130  1.0
  O  O24  1  0.908  0.503  0.870  1.0
  O  O25  1  0.038  0.908  0.405  1.0
  O  O26  1  0.497  0.367  0.405  1.0
  O  O27  1  0.367  0.962  0.870  1.0
  O  O28  1  0.092  0.497  0.130  1.0
  O  O29  1  0.962  0.092  0.595  1.0
  O  O30  1  0.727  0.582  0.774  1.0
  O  O31  1  0.582  0.807  0.855  1.0
  O  O32  1  0.952  0.727  0.145  1.0
  O  O33  1  0.807  0.952  0.226  1.0
  O  O34  1  0.273  0.418  0.226  1.0
  O  O35  1  0.418  0.193  0.145  1.0
  O  O36  1  0.048  0.273  0.855  1.0
  O  O37  1  0.193  0.048  0.774  1.0
[/CIF]
.
The compound described by Ba5Yb8Ni4O21 crystallizes in the tetragonal I4/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(4), four equivalent O(2), and four equivalent O(3) atoms. In the second Ba site, Ba(2) is bonded in a distorted q6 geometry to two equivalent O(1) and eight equivalent O(4) atoms. There are two inequivalent Yb sites. In the first Yb site, Yb(1) is bonded to one O(2), two equivalent O(4), and four equivalent O(3) atoms to form distorted YbO7 pentagonal bipyramids that share corners with two equivalent Yb(2)O7 pentagonal bipyramids, corners with two equivalent Ni(1)O5 square pyramids, edges with two equivalent Yb(1)O7 pentagonal bipyramids, edges with three equivalent Yb(2)O7 pentagonal bipyramids,  an edgeedge with one Ni(1)O5 square pyramid, and  a faceface with one Ni(1)O5 square pyramid. In the second Yb site, Yb(2) is bonded to one O(1), two equivalent O(3), and four equivalent O(4) atoms to form distorted YbO7 pentagonal bipyramids that share  a cornercorner with one Yb(2)O7 pentagonal bipyramid, corners with two equivalent Yb(1)O7 pentagonal bipyramids, corners with two equivalent Ni(1)O5 square pyramids, edges with three equivalent Yb(1)O7 pentagonal bipyramids, edges with two equivalent Ni(1)O5 square pyramids, and faces with two equivalent Yb(2)O7 pentagonal bipyramids. Ni(1) is bonded to one O(2), two equivalent O(3), and two equivalent O(4) atoms to form NiO5 square pyramids that share corners with two equivalent Yb(1)O7 pentagonal bipyramids, corners with two equivalent Yb(2)O7 pentagonal bipyramids,  an edgeedge with one Yb(1)O7 pentagonal bipyramid, edges with two equivalent Yb(2)O7 pentagonal bipyramids, and  a faceface with one Yb(1)O7 pentagonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ba(2) and four equivalent Yb(2) atoms to form OBa2Yb4 octahedra that share corners with two equivalent O(1)Ba2Yb4 octahedra, corners with eight equivalent O(4)Ba2Yb3Ni octahedra, and faces with eight equivalent O(4)Ba2Yb3Ni octahedra. The corner-sharing octahedral tilt angles range from 0-63°. In the second O site, O(2) is bonded to four equivalent Ba(1), one Yb(1), and one Ni(1) atom to form distorted OBa4YbNi octahedra that share corners with two equivalent O(2)Ba4YbNi octahedra, corners with six equivalent O(4)Ba2Yb3Ni octahedra, edges with five equivalent O(2)Ba4YbNi octahedra, and faces with two equivalent O(4)Ba2Yb3Ni octahedra. The corner-sharing octahedral tilt angles range from 6-59°. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Ba(1), one Yb(2), two equivalent Yb(1), and one Ni(1) atom. In the fourth O site, O(4) is bonded to one Ba(1), one Ba(2), one Yb(1), two equivalent Yb(2), and one Ni(1) atom to form distorted OBa2Yb3Ni octahedra that share  a cornercorner with one O(1)Ba2Yb4 octahedra, corners with three equivalent O(2)Ba4YbNi octahedra, corners with six equivalent O(4)Ba2Yb3Ni octahedra, edges with two equivalent O(4)Ba2Yb3Ni octahedra,  a faceface with one O(1)Ba2Yb4 octahedra,  a faceface with one O(2)Ba4YbNi octahedra, and faces with two equivalent O(4)Ba2Yb3Ni octahedra. The corner-sharing octahedral tilt angles range from 0-78°. is represented by the CIF card [CIF]
data_Ba5Yb8Ni4O21
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.970
_cell_length_b   9.970
_cell_length_c   9.970
_cell_angle_alpha   94.619
_cell_angle_beta   94.619
_cell_angle_gamma   147.028
_symmetry_Int_Tables_number   1
_cell_volume   517.200
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ba  Ba0  1  0.532  0.853  0.385  1.0
  Ba  Ba1  1  0.853  0.468  0.321  1.0
  Ba  Ba2  1  0.147  0.532  0.679  1.0
  Ba  Ba3  1  0.468  0.147  0.615  1.0
  Ba  Ba4  1  0.000  0.000  0.000  1.0
  Yb  Yb5  1  0.830  0.750  0.580  1.0
  Yb  Yb6  1  0.750  0.170  0.919  1.0
  Yb  Yb7  1  0.250  0.830  0.081  1.0
  Yb  Yb8  1  0.170  0.250  0.420  1.0
  Yb  Yb9  1  0.639  0.593  0.232  1.0
  Yb  Yb10  1  0.593  0.361  0.954  1.0
  Yb  Yb11  1  0.407  0.639  0.046  1.0
  Yb  Yb12  1  0.361  0.407  0.768  1.0
  Ni  Ni13  1  0.757  0.959  0.715  1.0
  Ni  Ni14  1  0.959  0.243  0.202  1.0
  Ni  Ni15  1  0.041  0.757  0.798  1.0
  Ni  Ni16  1  0.243  0.041  0.285  1.0
  O  O17  1  0.500  0.500  0.000  1.0
  O  O18  1  0.975  0.639  0.613  1.0
  O  O19  1  0.639  0.025  0.664  1.0
  O  O20  1  0.361  0.975  0.336  1.0
  O  O21  1  0.025  0.361  0.387  1.0
  O  O22  1  0.503  0.633  0.595  1.0
  O  O23  1  0.633  0.038  0.130  1.0
  O  O24  1  0.908  0.503  0.870  1.0
  O  O25  1  0.038  0.908  0.405  1.0
  O  O26  1  0.497  0.367  0.405  1.0
  O  O27  1  0.367  0.962  0.870  1.0
  O  O28  1  0.092  0.497  0.130  1.0
  O  O29  1  0.962  0.092  0.595  1.0
  O  O30  1  0.727  0.582  0.774  1.0
  O  O31  1  0.582  0.807  0.855  1.0
  O  O32  1  0.952  0.727  0.145  1.0
  O  O33  1  0.807  0.952  0.226  1.0
  O  O34  1  0.273  0.418  0.226  1.0
  O  O35  1  0.418  0.193  0.145  1.0
  O  O36  1  0.048  0.273  0.855  1.0
  O  O37  1  0.193  0.048  0.774  1.0
[/CIF]
.