The material described by MgCo2(SiO3)4 crystallizes in the monoclinic C2 space group. Mg(1) is bonded to two equivalent O(4) and two equivalent O(6) atoms to form distorted MgO4 trigonal pyramids that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Co(2)O4 tetrahedra. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(3) and two equivalent O(5) atoms to form distorted CoO4 tetrahedra that share corners with two equivalent Co(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the second Co site, Co(2) is bonded to two equivalent O(5) and two equivalent O(6) atoms to form CoO4 tetrahedra that share corners with two equivalent Co(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Mg(1)O4 trigonal pyramid. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Co(1)O4 tetrahedra,  a cornercorner with one Co(2)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  a cornercorner with one Mg(1)O4 trigonal pyramid. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Co(1)O4 tetrahedra,  a cornercorner with one Co(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and  a cornercorner with one Mg(1)O4 trigonal pyramid. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Co(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Mg(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Co(1), one Co(2), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mg(1), one Co(2), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgCo2(SiO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.980
_cell_length_b   7.799
_cell_length_c   7.799
_cell_angle_alpha   89.584
_cell_angle_beta   67.434
_cell_angle_gamma   67.446
_symmetry_Int_Tables_number   1
_cell_volume   254.826
_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
  Mg  Mg0  1  0.750  0.744  0.256  1.0
  Co  Co1  1  0.250  0.213  0.787  1.0
  Co  Co2  1  0.750  0.005  0.995  1.0
  Si  Si3  1  0.189  0.188  0.387  1.0
  Si  Si4  1  0.311  0.614  0.812  1.0
  Si  Si5  1  0.684  0.346  0.228  1.0
  Si  Si6  1  0.816  0.772  0.654  1.0
  O  O7  1  0.323  0.349  0.319  1.0
  O  O8  1  0.177  0.681  0.651  1.0
  O  O9  1  0.657  0.623  0.747  1.0
  O  O10  1  0.843  0.253  0.377  1.0
  O  O11  1  0.158  0.156  0.601  1.0
  O  O12  1  0.342  0.399  0.844  1.0
  O  O13  1  0.821  0.816  0.457  1.0
  O  O14  1  0.680  0.542  0.184  1.0
  O  O15  1  0.892  0.191  0.020  1.0
  O  O16  1  0.608  0.980  0.809  1.0
  O  O17  1  0.449  0.996  0.231  1.0
  O  O18  1  0.051  0.769  0.004  1.0
[/CIF]
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The material described by MgCo2(SiO3)4 crystallizes in the monoclinic C2 space group. Mg(1) is bonded to two equivalent O(4) and two equivalent O(6) atoms to form distorted MgO4 trigonal pyramids that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Co(2)O4 tetrahedra. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(3) and two equivalent O(5) atoms to form distorted CoO4 tetrahedra that share corners with two equivalent Co(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the second Co site, Co(2) is bonded to two equivalent O(5) and two equivalent O(6) atoms to form CoO4 tetrahedra that share corners with two equivalent Co(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Mg(1)O4 trigonal pyramid. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Co(1)O4 tetrahedra,  a cornercorner with one Co(2)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  a cornercorner with one Mg(1)O4 trigonal pyramid. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Co(1)O4 tetrahedra,  a cornercorner with one Co(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and  a cornercorner with one Mg(1)O4 trigonal pyramid. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Co(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Mg(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Co(1), one Co(2), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mg(1), one Co(2), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgCo2(SiO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.980
_cell_length_b   7.799
_cell_length_c   7.799
_cell_angle_alpha   89.584
_cell_angle_beta   67.434
_cell_angle_gamma   67.446
_symmetry_Int_Tables_number   1
_cell_volume   254.826
_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
  Mg  Mg0  1  0.750  0.744  0.256  1.0
  Co  Co1  1  0.250  0.213  0.787  1.0
  Co  Co2  1  0.750  0.005  0.995  1.0
  Si  Si3  1  0.189  0.188  0.387  1.0
  Si  Si4  1  0.311  0.614  0.812  1.0
  Si  Si5  1  0.684  0.346  0.228  1.0
  Si  Si6  1  0.816  0.772  0.654  1.0
  O  O7  1  0.323  0.349  0.319  1.0
  O  O8  1  0.177  0.681  0.651  1.0
  O  O9  1  0.657  0.623  0.747  1.0
  O  O10  1  0.843  0.253  0.377  1.0
  O  O11  1  0.158  0.156  0.601  1.0
  O  O12  1  0.342  0.399  0.844  1.0
  O  O13  1  0.821  0.816  0.457  1.0
  O  O14  1  0.680  0.542  0.184  1.0
  O  O15  1  0.892  0.191  0.020  1.0
  O  O16  1  0.608  0.980  0.809  1.0
  O  O17  1  0.449  0.996  0.231  1.0
  O  O18  1  0.051  0.769  0.004  1.0
[/CIF]
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