The material structure described by CaMg3(SiO3)4 is Esseneite-like structured and crystallizes in the monoclinic C2 space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and edges with two equivalent Mg(2)O6 octahedra. In the second Mg site, Mg(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Si(2)O4 tetrahedra, and edges with two equivalent Mg(1)O6 octahedra. In the third Mg site, Mg(3) is bonded in a rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(3) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(2)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-59°. In the second Si site, Si(2) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 36-60°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), one Mg(1), one Mg(2), and one Si(1) atom. In the second O site, O(2) is bonded to one Mg(1), one Mg(2), one Mg(3), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OMg3Si trigonal pyramids. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Mg(3), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Ca(1), one Mg(2), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ca(1), one Si(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ca(1), one Si(1), and one Si(2) atom. is represented by the CIF card [CIF]
data_CaMg3(SiO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.680
_cell_length_b   6.680
_cell_length_c   5.317
_cell_angle_alpha   76.989
_cell_angle_beta   76.989
_cell_angle_gamma   84.640
_symmetry_Int_Tables_number   1
_cell_volume   225.017
_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
  Ca  Ca0  1  0.300  0.700  0.500  1.0
  Mg  Mg1  1  0.907  0.093  0.500  1.0
  Mg  Mg2  1  0.095  0.905  0.000  1.0
  Mg  Mg3  1  0.746  0.254  0.000  1.0
  Si  Si4  1  0.800  0.617  0.500  1.0
  Si  Si5  1  0.383  0.200  0.500  1.0
  Si  Si6  1  0.196  0.383  0.007  1.0
  Si  Si7  1  0.617  0.804  0.993  1.0
  O  O8  1  0.971  0.791  0.398  1.0
  O  O9  1  0.209  0.029  0.602  1.0
  O  O10  1  0.024  0.208  0.105  1.0
  O  O11  1  0.792  0.976  0.895  1.0
  O  O12  1  0.868  0.380  0.610  1.0
  O  O13  1  0.620  0.132  0.390  1.0
  O  O14  1  0.111  0.616  0.923  1.0
  O  O15  1  0.384  0.889  0.077  1.0
  O  O16  1  0.664  0.635  0.264  1.0
  O  O17  1  0.365  0.336  0.736  1.0
  O  O18  1  0.325  0.375  0.242  1.0
  O  O19  1  0.625  0.675  0.758  1.0
[/CIF]
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The material structure described by CaMg3(SiO3)4 is Esseneite-like structured and crystallizes in the monoclinic C2 space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and edges with two equivalent Mg(2)O6 octahedra. In the second Mg site, Mg(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Si(2)O4 tetrahedra, and edges with two equivalent Mg(1)O6 octahedra. In the third Mg site, Mg(3) is bonded in a rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(3) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(2)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-59°. In the second Si site, Si(2) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 36-60°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), one Mg(1), one Mg(2), and one Si(1) atom. In the second O site, O(2) is bonded to one Mg(1), one Mg(2), one Mg(3), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OMg3Si trigonal pyramids. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Mg(3), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Ca(1), one Mg(2), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ca(1), one Si(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ca(1), one Si(1), and one Si(2) atom. is represented by the CIF card [CIF]
data_CaMg3(SiO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.680
_cell_length_b   6.680
_cell_length_c   5.317
_cell_angle_alpha   76.989
_cell_angle_beta   76.989
_cell_angle_gamma   84.640
_symmetry_Int_Tables_number   1
_cell_volume   225.017
_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
  Ca  Ca0  1  0.300  0.700  0.500  1.0
  Mg  Mg1  1  0.907  0.093  0.500  1.0
  Mg  Mg2  1  0.095  0.905  0.000  1.0
  Mg  Mg3  1  0.746  0.254  0.000  1.0
  Si  Si4  1  0.800  0.617  0.500  1.0
  Si  Si5  1  0.383  0.200  0.500  1.0
  Si  Si6  1  0.196  0.383  0.007  1.0
  Si  Si7  1  0.617  0.804  0.993  1.0
  O  O8  1  0.971  0.791  0.398  1.0
  O  O9  1  0.209  0.029  0.602  1.0
  O  O10  1  0.024  0.208  0.105  1.0
  O  O11  1  0.792  0.976  0.895  1.0
  O  O12  1  0.868  0.380  0.610  1.0
  O  O13  1  0.620  0.132  0.390  1.0
  O  O14  1  0.111  0.616  0.923  1.0
  O  O15  1  0.384  0.889  0.077  1.0
  O  O16  1  0.664  0.635  0.264  1.0
  O  O17  1  0.365  0.336  0.736  1.0
  O  O18  1  0.325  0.375  0.242  1.0
  O  O19  1  0.625  0.675  0.758  1.0
[/CIF]
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