The material described by MgCeZr7O16 is Esseneite-like structured and crystallizes in the orthorhombic Pmm2 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(7) atoms to form MgO6 octahedra that share edges with two equivalent Zr(3)O6 octahedra. Ce(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. There are four inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. In the second Zr site, Zr(2) is bonded in a 6-coordinate geometry to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. In the third Zr site, Zr(3) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(8) atoms to form ZrO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra. In the fourth Zr site, Zr(4) is bonded in a 8-coordinate geometry to two equivalent O(5), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ce(1), and one Zr(3) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ce(1) and two equivalent Zr(1) atoms. In the third O site, O(3) is bonded to one Ce(1), one Zr(2), and two equivalent Zr(1) atoms to form distorted OCeZr3 tetrahedra that share corners with two equivalent O(3)CeZr3 tetrahedra, corners with four equivalent O(5)Zr4 tetrahedra, corners with two equivalent O(4)MgZr3 trigonal pyramids, and edges with two equivalent O(6)Zr4 tetrahedra. In the fourth O site, O(4) is bonded to one Mg(1), one Zr(3), and two equivalent Zr(1) atoms to form distorted OMgZr3 trigonal pyramids that share corners with two equivalent O(3)CeZr3 tetrahedra, corners with two equivalent O(5)Zr4 tetrahedra, corners with two equivalent O(6)Zr4 tetrahedra, and  an edgeedge with one O(4)MgZr3 trigonal pyramid. In the fifth O site, O(5) is bonded to one Zr(2), one Zr(4), and two equivalent Zr(1) atoms to form OZr4 tetrahedra that share corners with two equivalent O(5)Zr4 tetrahedra, corners with two equivalent O(6)Zr4 tetrahedra, corners with four equivalent O(3)CeZr3 tetrahedra, corners with two equivalent O(4)MgZr3 trigonal pyramids, and edges with two equivalent O(6)Zr4 tetrahedra. In the sixth O site, O(6) is bonded to one Zr(2), one Zr(4), and two equivalent Zr(1) atoms to form OZr4 tetrahedra that share corners with two equivalent O(5)Zr4 tetrahedra, corners with two equivalent O(6)Zr4 tetrahedra, corners with two equivalent O(4)MgZr3 trigonal pyramids, edges with two equivalent O(3)CeZr3 tetrahedra, and edges with two equivalent O(5)Zr4 tetrahedra. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Mg(1), one Zr(4), and two equivalent Zr(1) atoms. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Zr(3), one Zr(4), and two equivalent Zr(1) atoms. is represented by the CIF file [CIF]
data_CeMgZr7O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.673
_cell_length_b   7.164
_cell_length_c   7.726
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   314.021
_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
  Ce  Ce0  1  0.024  0.000  0.000  1.0
  Mg  Mg1  1  0.370  0.500  0.000  1.0
  Zr  Zr2  1  0.521  0.232  0.284  1.0
  Zr  Zr3  1  0.970  0.000  0.500  1.0
  Zr  Zr4  1  0.521  0.232  0.716  1.0
  Zr  Zr5  1  0.887  0.500  0.000  1.0
  Zr  Zr6  1  0.521  0.768  0.284  1.0
  Zr  Zr7  1  0.031  0.500  0.500  1.0
  Zr  Zr8  1  0.521  0.768  0.716  1.0
  O  O9  1  0.135  0.296  0.000  1.0
  O  O10  1  0.321  0.000  0.219  1.0
  O  O11  1  0.800  0.000  0.259  1.0
  O  O12  1  0.613  0.283  0.000  1.0
  O  O13  1  0.231  0.232  0.500  1.0
  O  O14  1  0.321  0.000  0.781  1.0
  O  O15  1  0.800  0.000  0.741  1.0
  O  O16  1  0.748  0.261  0.500  1.0
  O  O17  1  0.135  0.704  0.000  1.0
  O  O18  1  0.370  0.500  0.274  1.0
  O  O19  1  0.849  0.500  0.268  1.0
  O  O20  1  0.613  0.717  0.000  1.0
  O  O21  1  0.231  0.768  0.500  1.0
  O  O22  1  0.370  0.500  0.726  1.0
  O  O23  1  0.849  0.500  0.732  1.0
  O  O24  1  0.748  0.739  0.500  1.0
[/CIF]
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The material described by MgCeZr7O16 is Esseneite-like structured and crystallizes in the orthorhombic Pmm2 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(7) atoms to form MgO6 octahedra that share edges with two equivalent Zr(3)O6 octahedra. Ce(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. There are four inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. In the second Zr site, Zr(2) is bonded in a 6-coordinate geometry to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. In the third Zr site, Zr(3) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(8) atoms to form ZrO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra. In the fourth Zr site, Zr(4) is bonded in a 8-coordinate geometry to two equivalent O(5), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ce(1), and one Zr(3) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ce(1) and two equivalent Zr(1) atoms. In the third O site, O(3) is bonded to one Ce(1), one Zr(2), and two equivalent Zr(1) atoms to form distorted OCeZr3 tetrahedra that share corners with two equivalent O(3)CeZr3 tetrahedra, corners with four equivalent O(5)Zr4 tetrahedra, corners with two equivalent O(4)MgZr3 trigonal pyramids, and edges with two equivalent O(6)Zr4 tetrahedra. In the fourth O site, O(4) is bonded to one Mg(1), one Zr(3), and two equivalent Zr(1) atoms to form distorted OMgZr3 trigonal pyramids that share corners with two equivalent O(3)CeZr3 tetrahedra, corners with two equivalent O(5)Zr4 tetrahedra, corners with two equivalent O(6)Zr4 tetrahedra, and  an edgeedge with one O(4)MgZr3 trigonal pyramid. In the fifth O site, O(5) is bonded to one Zr(2), one Zr(4), and two equivalent Zr(1) atoms to form OZr4 tetrahedra that share corners with two equivalent O(5)Zr4 tetrahedra, corners with two equivalent O(6)Zr4 tetrahedra, corners with four equivalent O(3)CeZr3 tetrahedra, corners with two equivalent O(4)MgZr3 trigonal pyramids, and edges with two equivalent O(6)Zr4 tetrahedra. In the sixth O site, O(6) is bonded to one Zr(2), one Zr(4), and two equivalent Zr(1) atoms to form OZr4 tetrahedra that share corners with two equivalent O(5)Zr4 tetrahedra, corners with two equivalent O(6)Zr4 tetrahedra, corners with two equivalent O(4)MgZr3 trigonal pyramids, edges with two equivalent O(3)CeZr3 tetrahedra, and edges with two equivalent O(5)Zr4 tetrahedra. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Mg(1), one Zr(4), and two equivalent Zr(1) atoms. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Zr(3), one Zr(4), and two equivalent Zr(1) atoms. is represented by the CIF file [CIF]
data_CeMgZr7O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.673
_cell_length_b   7.164
_cell_length_c   7.726
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   314.021
_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
  Ce  Ce0  1  0.024  0.000  0.000  1.0
  Mg  Mg1  1  0.370  0.500  0.000  1.0
  Zr  Zr2  1  0.521  0.232  0.284  1.0
  Zr  Zr3  1  0.970  0.000  0.500  1.0
  Zr  Zr4  1  0.521  0.232  0.716  1.0
  Zr  Zr5  1  0.887  0.500  0.000  1.0
  Zr  Zr6  1  0.521  0.768  0.284  1.0
  Zr  Zr7  1  0.031  0.500  0.500  1.0
  Zr  Zr8  1  0.521  0.768  0.716  1.0
  O  O9  1  0.135  0.296  0.000  1.0
  O  O10  1  0.321  0.000  0.219  1.0
  O  O11  1  0.800  0.000  0.259  1.0
  O  O12  1  0.613  0.283  0.000  1.0
  O  O13  1  0.231  0.232  0.500  1.0
  O  O14  1  0.321  0.000  0.781  1.0
  O  O15  1  0.800  0.000  0.741  1.0
  O  O16  1  0.748  0.261  0.500  1.0
  O  O17  1  0.135  0.704  0.000  1.0
  O  O18  1  0.370  0.500  0.274  1.0
  O  O19  1  0.849  0.500  0.268  1.0
  O  O20  1  0.613  0.717  0.000  1.0
  O  O21  1  0.231  0.768  0.500  1.0
  O  O22  1  0.370  0.500  0.726  1.0
  O  O23  1  0.849  0.500  0.732  1.0
  O  O24  1  0.748  0.739  0.500  1.0
[/CIF]
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