The material described by Ca2MgFe(SiO3)4 is Esseneite-derived structured and crystallizes in the triclinic P1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(10), one O(12), one O(17), one O(19), one O(21), one O(23), one O(5), and one O(7) atom. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(11), one O(18), one O(20), one O(22), one O(24), one O(6), one O(8), and one O(9) atom. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one O(1), one O(14), one O(16), one O(17), one O(19), one O(21), one O(23), and one O(3) atom. In the fourth Ca site, Ca(4) is bonded in a 8-coordinate geometry to one O(13), one O(15), one O(18), one O(2), one O(20), one O(22), one O(24), and one O(4) atom. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), one O(10), one O(12), one O(14), one O(16), and one O(3) atom to form MgO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra,  a cornercorner with one Si(8)O4 tetrahedra, and edges with two equivalent Fe(2)O6 octahedra. In the second Mg site, Mg(2) is bonded to one O(11), one O(13), one O(15), one O(2), one O(4), and one O(9) atom to form MgO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(11), one O(13), one O(15), one O(6), one O(8), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra,  a cornercorner with one Si(8)O4 tetrahedra, and edges with two equivalent Mg(2)O6 octahedra. In the second Fe site, Fe(2) is bonded to one O(10), one O(12), one O(14), one O(16), one O(5), and one O(7) atom to form FeO6 octahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra,  a cornercorner with one Si(8)O4 tetrahedra, and edges with two equivalent Mg(1)O6 octahedra. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(17), one O(23), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, and corners with two equivalent Si(7)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-60°. In the second Si site, Si(2) is bonded to one O(10), one O(18), one O(2), and one O(24) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with two equivalent Si(8)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 33-59°. In the third Si site, Si(3) is bonded to one O(11), one O(19), one O(21), and one O(3) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, and corners with two equivalent Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 33-59°. In the fourth Si site, Si(4) is bonded to one O(12), one O(20), one O(22), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with two equivalent Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-59°. In the fifth Si site, Si(5) is bonded to one O(13), one O(19), one O(21), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with two equivalent Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-59°. In the sixth Si site, Si(6) is bonded to one O(14), one O(20), one O(22), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with two equivalent Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-60°. In the seventh Si site, Si(7) is bonded to one O(15), one O(17), one O(23), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-60°. In the eighth Si site, Si(8) is bonded to one O(16), one O(18), one O(24), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-59°. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Ca(3), one Mg(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ca(4), one Mg(2), and one Si(2) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Ca(3), one Mg(1), and one Si(3) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Ca(4), one Mg(2), and one Si(4) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Ca(1), one Fe(2), and one Si(5) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Ca(2), one Fe(1), and one Si(6) atom. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Ca(1), one Fe(2), and one Si(7) atom. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Ca(2), one Fe(1), and one Si(8) atom. In the ninth O site, O(9) is bonded to one Ca(2), one Mg(2), one Fe(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OCaMgFeSi trigonal pyramids. In the tenth O site, O(10) is bonded to one Ca(1), one Mg(1), one Fe(2), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OCaMgFeSi trigonal pyramids. In the eleventh O site, O(11) is bonded to one Ca(2), one Mg(2), one Fe(1), and one Si(3) atom to form a mixture of distorted corner and edge-sharing OCaMgFeSi trigonal pyramids. In the twelfth O site, O(12) is bonded to one Ca(1), one Mg(1), one Fe(2), and one Si(4) atom to form a mixture of distorted corner and edge-sharing OCaMgFeSi trigonal pyramids. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one Ca(4), one Mg(2), one Fe(1), and one Si(5) atom. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Ca(3), one Mg(1), one Fe(2), and one Si(6) atom. In the fifteenth O site, O(15) is bonded to one Ca(4), one Mg(2), one Fe(1), and one Si(7) atom to form a mixture of distorted corner and edge-sharing OCaMgFeSi trigonal pyramids. In the sixteenth O site, O(16) is bonded in a 4-coordinate geometry to one Ca(3), one Mg(1), one Fe(2), and one Si(8) atom. In the seventeenth O site, O(17) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(3), one Si(1), and one Si(7) atom. In the eighteenth O site, O(18) is bonded in a 2-coordinate geometry to one Ca(2), one Ca(4), one Si(2), and one Si(8) atom. In the nineteenth O site, O(19) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(3), one Si(3), and one Si(5) atom. In the twentieth O site, O(20) is bonded in a 2-coordinate geometry to one Ca(2), one Ca(4), one Si(4), and one Si(6) atom. In the twenty-first O site, O(21) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(3), one Si(3), and one Si(5) atom. In the twenty-second O site, O(22) is bonded in a 2-coordinate geometry to one Ca(2), one Ca(4), one Si(4), and one Si(6) atom. In the twenty-third O site, O(23) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(3), one Si(1), and one Si(7) atom. In the twenty-fourth O site, O(24) is bonded in a 2-coordinate geometry to one Ca(2), one Ca(4), one Si(2), and one Si(8) atom. is represented by the CIF card [CIF]
data_Ca2MgFe(SiO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.331
_cell_length_b   6.722
_cell_length_c   6.744
_cell_angle_alpha   84.970
_cell_angle_beta   78.381
_cell_angle_gamma   78.410
_symmetry_Int_Tables_number   1
_cell_volume   231.597
_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  0.749  0.703  0.297  1.0
  Ca  Ca1  1  0.250  0.300  0.700  1.0
  Fe  Fe2  1  0.250  0.907  0.093  1.0
  Mg  Mg3  1  0.750  0.092  0.907  1.0
  O  O4  1  0.823  0.387  0.883  1.0
  O  O5  1  0.677  0.117  0.612  1.0
  O  O6  1  0.178  0.609  0.116  1.0
  O  O7  1  0.324  0.884  0.392  1.0
  O  O8  1  0.655  0.794  0.969  1.0
  O  O9  1  0.846  0.031  0.206  1.0
  O  O10  1  0.358  0.206  0.027  1.0
  O  O11  1  0.141  0.975  0.792  1.0
  O  O12  1  0.498  0.634  0.670  1.0
  O  O13  1  0.002  0.331  0.366  1.0
  O  O14  1  0.499  0.368  0.335  1.0
  O  O15  1  0.001  0.665  0.632  1.0
  Si  Si16  1  0.735  0.619  0.805  1.0
  Si  Si17  1  0.765  0.195  0.381  1.0
  Si  Si18  1  0.268  0.378  0.195  1.0
  Si  Si19  1  0.232  0.805  0.622  1.0
[/CIF]
.
The material described by Ca2MgFe(SiO3)4 is Esseneite-derived structured and crystallizes in the triclinic P1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(10), one O(12), one O(17), one O(19), one O(21), one O(23), one O(5), and one O(7) atom. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(11), one O(18), one O(20), one O(22), one O(24), one O(6), one O(8), and one O(9) atom. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one O(1), one O(14), one O(16), one O(17), one O(19), one O(21), one O(23), and one O(3) atom. In the fourth Ca site, Ca(4) is bonded in a 8-coordinate geometry to one O(13), one O(15), one O(18), one O(2), one O(20), one O(22), one O(24), and one O(4) atom. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), one O(10), one O(12), one O(14), one O(16), and one O(3) atom to form MgO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra,  a cornercorner with one Si(8)O4 tetrahedra, and edges with two equivalent Fe(2)O6 octahedra. In the second Mg site, Mg(2) is bonded to one O(11), one O(13), one O(15), one O(2), one O(4), and one O(9) atom to form MgO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra, and edges with two equivalent Fe(1)O6 octahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(11), one O(13), one O(15), one O(6), one O(8), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra,  a cornercorner with one Si(8)O4 tetrahedra, and edges with two equivalent Mg(2)O6 octahedra. In the second Fe site, Fe(2) is bonded to one O(10), one O(12), one O(14), one O(16), one O(5), and one O(7) atom to form FeO6 octahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra,  a cornercorner with one Si(7)O4 tetrahedra,  a cornercorner with one Si(8)O4 tetrahedra, and edges with two equivalent Mg(1)O6 octahedra. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(17), one O(23), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, and corners with two equivalent Si(7)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-60°. In the second Si site, Si(2) is bonded to one O(10), one O(18), one O(2), and one O(24) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with two equivalent Si(8)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 33-59°. In the third Si site, Si(3) is bonded to one O(11), one O(19), one O(21), and one O(3) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, and corners with two equivalent Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 33-59°. In the fourth Si site, Si(4) is bonded to one O(12), one O(20), one O(22), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with two equivalent Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-59°. In the fifth Si site, Si(5) is bonded to one O(13), one O(19), one O(21), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with two equivalent Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-59°. In the sixth Si site, Si(6) is bonded to one O(14), one O(20), one O(22), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with two equivalent Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-60°. In the seventh Si site, Si(7) is bonded to one O(15), one O(17), one O(23), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(2)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-60°. In the eighth Si site, Si(8) is bonded to one O(16), one O(18), one O(24), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-59°. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Ca(3), one Mg(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ca(4), one Mg(2), and one Si(2) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Ca(3), one Mg(1), and one Si(3) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Ca(4), one Mg(2), and one Si(4) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Ca(1), one Fe(2), and one Si(5) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Ca(2), one Fe(1), and one Si(6) atom. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Ca(1), one Fe(2), and one Si(7) atom. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Ca(2), one Fe(1), and one Si(8) atom. In the ninth O site, O(9) is bonded to one Ca(2), one Mg(2), one Fe(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OCaMgFeSi trigonal pyramids. In the tenth O site, O(10) is bonded to one Ca(1), one Mg(1), one Fe(2), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OCaMgFeSi trigonal pyramids. In the eleventh O site, O(11) is bonded to one Ca(2), one Mg(2), one Fe(1), and one Si(3) atom to form a mixture of distorted corner and edge-sharing OCaMgFeSi trigonal pyramids. In the twelfth O site, O(12) is bonded to one Ca(1), one Mg(1), one Fe(2), and one Si(4) atom to form a mixture of distorted corner and edge-sharing OCaMgFeSi trigonal pyramids. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one Ca(4), one Mg(2), one Fe(1), and one Si(5) atom. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Ca(3), one Mg(1), one Fe(2), and one Si(6) atom. In the fifteenth O site, O(15) is bonded to one Ca(4), one Mg(2), one Fe(1), and one Si(7) atom to form a mixture of distorted corner and edge-sharing OCaMgFeSi trigonal pyramids. In the sixteenth O site, O(16) is bonded in a 4-coordinate geometry to one Ca(3), one Mg(1), one Fe(2), and one Si(8) atom. In the seventeenth O site, O(17) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(3), one Si(1), and one Si(7) atom. In the eighteenth O site, O(18) is bonded in a 2-coordinate geometry to one Ca(2), one Ca(4), one Si(2), and one Si(8) atom. In the nineteenth O site, O(19) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(3), one Si(3), and one Si(5) atom. In the twentieth O site, O(20) is bonded in a 2-coordinate geometry to one Ca(2), one Ca(4), one Si(4), and one Si(6) atom. In the twenty-first O site, O(21) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(3), one Si(3), and one Si(5) atom. In the twenty-second O site, O(22) is bonded in a 2-coordinate geometry to one Ca(2), one Ca(4), one Si(4), and one Si(6) atom. In the twenty-third O site, O(23) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(3), one Si(1), and one Si(7) atom. In the twenty-fourth O site, O(24) is bonded in a 2-coordinate geometry to one Ca(2), one Ca(4), one Si(2), and one Si(8) atom. is represented by the CIF card [CIF]
data_Ca2MgFe(SiO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.331
_cell_length_b   6.722
_cell_length_c   6.744
_cell_angle_alpha   84.970
_cell_angle_beta   78.381
_cell_angle_gamma   78.410
_symmetry_Int_Tables_number   1
_cell_volume   231.597
_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  0.749  0.703  0.297  1.0
  Ca  Ca1  1  0.250  0.300  0.700  1.0
  Fe  Fe2  1  0.250  0.907  0.093  1.0
  Mg  Mg3  1  0.750  0.092  0.907  1.0
  O  O4  1  0.823  0.387  0.883  1.0
  O  O5  1  0.677  0.117  0.612  1.0
  O  O6  1  0.178  0.609  0.116  1.0
  O  O7  1  0.324  0.884  0.392  1.0
  O  O8  1  0.655  0.794  0.969  1.0
  O  O9  1  0.846  0.031  0.206  1.0
  O  O10  1  0.358  0.206  0.027  1.0
  O  O11  1  0.141  0.975  0.792  1.0
  O  O12  1  0.498  0.634  0.670  1.0
  O  O13  1  0.002  0.331  0.366  1.0
  O  O14  1  0.499  0.368  0.335  1.0
  O  O15  1  0.001  0.665  0.632  1.0
  Si  Si16  1  0.735  0.619  0.805  1.0
  Si  Si17  1  0.765  0.195  0.381  1.0
  Si  Si18  1  0.268  0.378  0.195  1.0
  Si  Si19  1  0.232  0.805  0.622  1.0
[/CIF]
.