The crystal structure described by NiSi2O6 crystallizes in the monoclinic C2/c space group. Ni(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form NiO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Ni(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 Ni(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 36-61°. 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 bent 150 degrees geometry to one Ni(1) and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Ni(1) and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Si2NiO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.389
_cell_length_b   6.389
_cell_length_c   5.318
_cell_angle_alpha   74.760
_cell_angle_beta   74.760
_cell_angle_gamma   83.595
_symmetry_Int_Tables_number   1
_cell_volume   201.879
_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
  Si  Si0  1  0.289  0.113  0.744  1.0
  Si  Si1  1  0.711  0.887  0.256  1.0
  Si  Si2  1  0.887  0.711  0.756  1.0
  Si  Si3  1  0.113  0.289  0.244  1.0
  Ni  Ni4  1  0.414  0.586  0.750  1.0
  Ni  Ni5  1  0.586  0.414  0.250  1.0
  O  O6  1  0.862  0.857  0.464  1.0
  O  O7  1  0.417  0.876  0.784  1.0
  O  O8  1  0.695  0.529  0.863  1.0
  O  O9  1  0.138  0.143  0.536  1.0
  O  O10  1  0.583  0.124  0.216  1.0
  O  O11  1  0.305  0.471  0.137  1.0
  O  O12  1  0.124  0.583  0.716  1.0
  O  O13  1  0.471  0.305  0.637  1.0
  O  O14  1  0.857  0.862  0.964  1.0
  O  O15  1  0.143  0.138  0.036  1.0
  O  O16  1  0.529  0.695  0.363  1.0
  O  O17  1  0.876  0.417  0.284  1.0
[/CIF]
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The crystal structure described by NiSi2O6 crystallizes in the monoclinic C2/c space group. Ni(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form NiO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Ni(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 Ni(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 36-61°. 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 bent 150 degrees geometry to one Ni(1) and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Ni(1) and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Si2NiO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.389
_cell_length_b   6.389
_cell_length_c   5.318
_cell_angle_alpha   74.760
_cell_angle_beta   74.760
_cell_angle_gamma   83.595
_symmetry_Int_Tables_number   1
_cell_volume   201.879
_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
  Si  Si0  1  0.289  0.113  0.744  1.0
  Si  Si1  1  0.711  0.887  0.256  1.0
  Si  Si2  1  0.887  0.711  0.756  1.0
  Si  Si3  1  0.113  0.289  0.244  1.0
  Ni  Ni4  1  0.414  0.586  0.750  1.0
  Ni  Ni5  1  0.586  0.414  0.250  1.0
  O  O6  1  0.862  0.857  0.464  1.0
  O  O7  1  0.417  0.876  0.784  1.0
  O  O8  1  0.695  0.529  0.863  1.0
  O  O9  1  0.138  0.143  0.536  1.0
  O  O10  1  0.583  0.124  0.216  1.0
  O  O11  1  0.305  0.471  0.137  1.0
  O  O12  1  0.124  0.583  0.716  1.0
  O  O13  1  0.471  0.305  0.637  1.0
  O  O14  1  0.857  0.862  0.964  1.0
  O  O15  1  0.143  0.138  0.036  1.0
  O  O16  1  0.529  0.695  0.363  1.0
  O  O17  1  0.876  0.417  0.284  1.0
[/CIF]
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