The compound described by Ca4CoSi8(NiO8)3 is Esseneite-derived structured and crystallizes in the monoclinic P2 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(11), two equivalent O(2), two equivalent O(5), and two equivalent O(7) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(12), two equivalent O(6), and two equivalent O(8) atoms. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to two equivalent O(4), two equivalent O(5), two equivalent O(7), and two equivalent O(9) atoms. In the fourth Ca site, Ca(4) is bonded in a 8-coordinate geometry to two equivalent O(10), two equivalent O(3), two equivalent O(6), and two equivalent O(8) atoms. Co(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(9) atoms to form CoO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and edges with two equivalent Ni(2)O6 octahedra. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(1), two equivalent O(10), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Ni(3)O6 octahedra. In the second Ni site, Ni(2) is bonded to two equivalent O(11), two equivalent O(2), and two equivalent O(4) atoms to form NiO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and edges with two equivalent Co(1)O6 octahedra. In the third Ni site, Ni(3) is bonded to two equivalent O(1), two equivalent O(12), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and edges with two equivalent Ni(1)O6 octahedra. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(5), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra, and corners with two equivalent Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-58°. In the second Si site, Si(2) is bonded to one O(10), one O(2), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra, and corners with two equivalent Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-58°. In the third Si site, Si(3) is bonded to one O(11), one O(3), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-58°. In the fourth Si site, Si(4) is bonded to one O(12), one O(4), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-59°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(2), one Ni(1), one Ni(3), and one Si(1) atom. In the second O site, O(2) is bonded to one Ca(1), one Co(1), one Ni(2), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OCaCoSiNi trigonal pyramids. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(4), one Ni(1), one Ni(3), and one Si(3) atom. In the fourth O site, O(4) is bonded to one Ca(3), one Co(1), one Ni(2), and one Si(4) atom to form a mixture of distorted corner and edge-sharing OCaCoSiNi trigonal pyramids. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(3), one Si(1), and one Si(3) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ca(2), one Ca(4), one Si(2), and one Si(4) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(3), one Si(1), and one Si(3) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Ca(2), one Ca(4), one Si(2), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Ca(3), one Co(1), and one Si(1) atom. In the tenth O site, O(10) is bonded in a distorted T-shaped geometry to one Ca(4), one Ni(1), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a distorted T-shaped geometry to one Ca(1), one Ni(2), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a distorted T-shaped geometry to one Ca(2), one Ni(3), and one Si(4) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca4CoSi8(NiO8)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.999
_cell_length_b   5.309
_cell_length_c   9.859
_cell_angle_alpha   74.785
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   454.463
_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  0.797  0.500  0.500  1.0
  Ca  Ca1  1  0.297  0.000  0.000  1.0
  Ca  Ca2  1  0.203  0.000  0.500  1.0
  Ca  Ca3  1  0.703  0.500  0.000  1.0
  Co  Co4  1  0.407  0.500  0.500  1.0
  Si  Si5  1  0.092  0.692  0.286  1.0
  Si  Si6  1  0.593  0.191  0.787  1.0
  Si  Si7  1  0.092  0.308  0.714  1.0
  Si  Si8  1  0.593  0.809  0.213  1.0
  Si  Si9  1  0.907  0.808  0.714  1.0
  Si  Si10  1  0.407  0.308  0.213  1.0
  Si  Si11  1  0.907  0.192  0.286  1.0
  Si  Si12  1  0.407  0.692  0.787  1.0
  Ni  Ni13  1  0.909  0.000  0.000  1.0
  Ni  Ni14  1  0.591  0.000  0.500  1.0
  Ni  Ni15  1  0.091  0.500  0.000  1.0
  O  O16  1  0.088  0.777  0.116  1.0
  O  O17  1  0.589  0.276  0.616  1.0
  O  O18  1  0.088  0.223  0.884  1.0
  O  O19  1  0.589  0.724  0.384  1.0
  O  O20  1  0.912  0.723  0.884  1.0
  O  O21  1  0.412  0.220  0.384  1.0
  O  O22  1  0.912  0.277  0.116  1.0
  O  O23  1  0.412  0.780  0.616  1.0
  O  O24  1  0.019  0.393  0.349  1.0
  O  O25  1  0.519  0.893  0.850  1.0
  O  O26  1  0.019  0.607  0.651  1.0
  O  O27  1  0.519  0.107  0.150  1.0
  O  O28  1  0.981  0.107  0.651  1.0
  O  O29  1  0.481  0.607  0.151  1.0
  O  O30  1  0.981  0.893  0.349  1.0
  O  O31  1  0.481  0.393  0.849  1.0
  O  O32  1  0.249  0.710  0.362  1.0
  O  O33  1  0.749  0.209  0.863  1.0
  O  O34  1  0.249  0.290  0.638  1.0
  O  O35  1  0.749  0.791  0.137  1.0
  O  O36  1  0.751  0.791  0.637  1.0
  O  O37  1  0.251  0.291  0.137  1.0
  O  O38  1  0.751  0.209  0.363  1.0
  O  O39  1  0.251  0.709  0.863  1.0
[/CIF]
.
The compound described by Ca4CoSi8(NiO8)3 is Esseneite-derived structured and crystallizes in the monoclinic P2 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(11), two equivalent O(2), two equivalent O(5), and two equivalent O(7) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(12), two equivalent O(6), and two equivalent O(8) atoms. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to two equivalent O(4), two equivalent O(5), two equivalent O(7), and two equivalent O(9) atoms. In the fourth Ca site, Ca(4) is bonded in a 8-coordinate geometry to two equivalent O(10), two equivalent O(3), two equivalent O(6), and two equivalent O(8) atoms. Co(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(9) atoms to form CoO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and edges with two equivalent Ni(2)O6 octahedra. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(1), two equivalent O(10), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Ni(3)O6 octahedra. In the second Ni site, Ni(2) is bonded to two equivalent O(11), two equivalent O(2), and two equivalent O(4) atoms to form NiO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and edges with two equivalent Co(1)O6 octahedra. In the third Ni site, Ni(3) is bonded to two equivalent O(1), two equivalent O(12), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and edges with two equivalent Ni(1)O6 octahedra. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(5), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra, and corners with two equivalent Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-58°. In the second Si site, Si(2) is bonded to one O(10), one O(2), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra, and corners with two equivalent Si(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-58°. In the third Si site, Si(3) is bonded to one O(11), one O(3), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-58°. In the fourth Si site, Si(4) is bonded to one O(12), one O(4), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-59°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(2), one Ni(1), one Ni(3), and one Si(1) atom. In the second O site, O(2) is bonded to one Ca(1), one Co(1), one Ni(2), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OCaCoSiNi trigonal pyramids. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(4), one Ni(1), one Ni(3), and one Si(3) atom. In the fourth O site, O(4) is bonded to one Ca(3), one Co(1), one Ni(2), and one Si(4) atom to form a mixture of distorted corner and edge-sharing OCaCoSiNi trigonal pyramids. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(3), one Si(1), and one Si(3) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ca(2), one Ca(4), one Si(2), and one Si(4) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(3), one Si(1), and one Si(3) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Ca(2), one Ca(4), one Si(2), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Ca(3), one Co(1), and one Si(1) atom. In the tenth O site, O(10) is bonded in a distorted T-shaped geometry to one Ca(4), one Ni(1), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a distorted T-shaped geometry to one Ca(1), one Ni(2), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a distorted T-shaped geometry to one Ca(2), one Ni(3), and one Si(4) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca4CoSi8(NiO8)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.999
_cell_length_b   5.309
_cell_length_c   9.859
_cell_angle_alpha   74.785
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   454.463
_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  0.797  0.500  0.500  1.0
  Ca  Ca1  1  0.297  0.000  0.000  1.0
  Ca  Ca2  1  0.203  0.000  0.500  1.0
  Ca  Ca3  1  0.703  0.500  0.000  1.0
  Co  Co4  1  0.407  0.500  0.500  1.0
  Si  Si5  1  0.092  0.692  0.286  1.0
  Si  Si6  1  0.593  0.191  0.787  1.0
  Si  Si7  1  0.092  0.308  0.714  1.0
  Si  Si8  1  0.593  0.809  0.213  1.0
  Si  Si9  1  0.907  0.808  0.714  1.0
  Si  Si10  1  0.407  0.308  0.213  1.0
  Si  Si11  1  0.907  0.192  0.286  1.0
  Si  Si12  1  0.407  0.692  0.787  1.0
  Ni  Ni13  1  0.909  0.000  0.000  1.0
  Ni  Ni14  1  0.591  0.000  0.500  1.0
  Ni  Ni15  1  0.091  0.500  0.000  1.0
  O  O16  1  0.088  0.777  0.116  1.0
  O  O17  1  0.589  0.276  0.616  1.0
  O  O18  1  0.088  0.223  0.884  1.0
  O  O19  1  0.589  0.724  0.384  1.0
  O  O20  1  0.912  0.723  0.884  1.0
  O  O21  1  0.412  0.220  0.384  1.0
  O  O22  1  0.912  0.277  0.116  1.0
  O  O23  1  0.412  0.780  0.616  1.0
  O  O24  1  0.019  0.393  0.349  1.0
  O  O25  1  0.519  0.893  0.850  1.0
  O  O26  1  0.019  0.607  0.651  1.0
  O  O27  1  0.519  0.107  0.150  1.0
  O  O28  1  0.981  0.107  0.651  1.0
  O  O29  1  0.481  0.607  0.151  1.0
  O  O30  1  0.981  0.893  0.349  1.0
  O  O31  1  0.481  0.393  0.849  1.0
  O  O32  1  0.249  0.710  0.362  1.0
  O  O33  1  0.749  0.209  0.863  1.0
  O  O34  1  0.249  0.290  0.638  1.0
  O  O35  1  0.749  0.791  0.137  1.0
  O  O36  1  0.751  0.791  0.637  1.0
  O  O37  1  0.251  0.291  0.137  1.0
  O  O38  1  0.751  0.209  0.363  1.0
  O  O39  1  0.251  0.709  0.863  1.0
[/CIF]
.