The material described by MgCo(SiO3)2 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Mg(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(3) atoms. Co(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form CoO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Co(1)O6 octahedra. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-61°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Co(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), two equivalent Co(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_MgCo(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.299
_cell_length_b   6.696
_cell_length_c   6.696
_cell_angle_alpha   85.797
_cell_angle_beta   76.446
_cell_angle_gamma   76.447
_symmetry_Int_Tables_number   1
_cell_volume   224.505
_cell_formula_units_Z   2
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
  Co  Co0  1  0.250  0.101  0.899  1.0
  Co  Co1  1  0.750  0.899  0.101  1.0
  Mg  Mg2  1  0.750  0.245  0.755  1.0
  Mg  Mg3  1  0.250  0.755  0.245  1.0
  O  O4  1  0.498  0.319  0.384  1.0
  O  O5  1  0.002  0.616  0.681  1.0
  O  O6  1  0.502  0.681  0.616  1.0
  O  O7  1  0.998  0.384  0.319  1.0
  O  O8  1  0.130  0.138  0.619  1.0
  O  O9  1  0.371  0.381  0.862  1.0
  O  O10  1  0.871  0.862  0.381  1.0
  O  O11  1  0.629  0.619  0.138  1.0
  O  O12  1  0.849  0.212  0.031  1.0
  O  O13  1  0.650  0.970  0.788  1.0
  O  O14  1  0.350  0.030  0.212  1.0
  O  O15  1  0.151  0.788  0.969  1.0
  Si  Si16  1  0.246  0.210  0.386  1.0
  Si  Si17  1  0.254  0.614  0.790  1.0
  Si  Si18  1  0.746  0.386  0.210  1.0
  Si  Si19  1  0.754  0.790  0.614  1.0
[/CIF]
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The material described by MgCo(SiO3)2 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Mg(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(3) atoms. Co(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form CoO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Co(1)O6 octahedra. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-61°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Co(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), two equivalent Co(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_MgCo(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.299
_cell_length_b   6.696
_cell_length_c   6.696
_cell_angle_alpha   85.797
_cell_angle_beta   76.446
_cell_angle_gamma   76.447
_symmetry_Int_Tables_number   1
_cell_volume   224.505
_cell_formula_units_Z   2
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
  Co  Co0  1  0.250  0.101  0.899  1.0
  Co  Co1  1  0.750  0.899  0.101  1.0
  Mg  Mg2  1  0.750  0.245  0.755  1.0
  Mg  Mg3  1  0.250  0.755  0.245  1.0
  O  O4  1  0.498  0.319  0.384  1.0
  O  O5  1  0.002  0.616  0.681  1.0
  O  O6  1  0.502  0.681  0.616  1.0
  O  O7  1  0.998  0.384  0.319  1.0
  O  O8  1  0.130  0.138  0.619  1.0
  O  O9  1  0.371  0.381  0.862  1.0
  O  O10  1  0.871  0.862  0.381  1.0
  O  O11  1  0.629  0.619  0.138  1.0
  O  O12  1  0.849  0.212  0.031  1.0
  O  O13  1  0.650  0.970  0.788  1.0
  O  O14  1  0.350  0.030  0.212  1.0
  O  O15  1  0.151  0.788  0.969  1.0
  Si  Si16  1  0.246  0.210  0.386  1.0
  Si  Si17  1  0.254  0.614  0.790  1.0
  Si  Si18  1  0.746  0.386  0.210  1.0
  Si  Si19  1  0.754  0.790  0.614  1.0
[/CIF]
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