The compound described by Li2NiSi2O6 crystallizes in the triclinic P1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(10), one O(4), one O(5), and one O(6) atom to form LiO4 tetrahedra that share  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(3), one O(5), one O(6), and one O(9) atom to form LiO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the third Li site, Li(3) is bonded to one O(12), one O(2), one O(7), and one O(8) atom to form LiO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and corners with two equivalent Si(4)O4 tetrahedra. In the fourth Li site, Li(4) is bonded to one O(1), one O(11), one O(7), and one O(8) atom to form LiO4 tetrahedra that share  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and corners with two equivalent Si(4)O4 tetrahedra. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(4), one O(5), and one O(8) atom to form NiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(3)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(4)O4 tetrahedra. In the second Ni site, Ni(2) is bonded to one O(2), one O(3), one O(6), and one O(7) atom to form NiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(5), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(4)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(10), one O(2), one O(6), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(3)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(11), one O(12), one O(3), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra, and corners with two equivalent Si(4)O4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(11), one O(12), one O(4), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Li(4), one Ni(1), and one Si(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(3), one Ni(2), and one Si(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Li(2), one Ni(2), and one Si(3) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(1), one Ni(1), and one Si(4) atom. In the fifth O site, O(5) is bonded to one Li(1), one Li(2), one Ni(1), and one Si(1) atom to form corner-sharing OLi2SiNi tetrahedra. In the sixth O site, O(6) is bonded to one Li(1), one Li(2), one Ni(2), and one Si(2) atom to form corner-sharing OLi2SiNi tetrahedra. In the seventh O site, O(7) is bonded to one Li(3), one Li(4), one Ni(2), and one Si(3) atom to form corner-sharing OLi2SiNi tetrahedra. In the eighth O site, O(8) is bonded to one Li(3), one Li(4), one Ni(1), and one Si(4) atom to form corner-sharing OLi2SiNi tetrahedra. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Li(2), one Si(1), and one Si(2) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Li(1), one Si(1), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Li(4), one Si(3), and one Si(4) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Li(3), one Si(3), and one Si(4) atom. is represented by the CIF card [CIF]
data_Li2Si2NiO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.123
_cell_length_b   10.430
_cell_length_c   5.128
_cell_angle_alpha   104.450
_cell_angle_beta   90.721
_cell_angle_gamma   75.519
_symmetry_Int_Tables_number   1
_cell_volume   256.538
_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
  Li  Li0  1  0.523  0.835  0.913  1.0
  Li  Li1  1  0.115  0.667  0.828  1.0
  Li  Li2  1  0.827  0.335  0.115  1.0
  Li  Li3  1  0.913  0.167  0.523  1.0
  Si  Si4  1  0.171  0.839  0.399  1.0
  Si  Si5  1  0.757  0.667  0.314  1.0
  Si  Si6  1  0.313  0.334  0.757  1.0
  Si  Si7  1  0.398  0.162  0.171  1.0
  Ni  Ni8  1  0.965  0.000  0.965  1.0
  Ni  Ni9  1  0.725  0.501  0.725  1.0
  O  O10  1  0.057  0.992  0.594  1.0
  O  O11  1  0.785  0.516  0.358  1.0
  O  O12  1  0.359  0.485  0.785  1.0
  O  O13  1  0.594  0.010  0.058  1.0
  O  O14  1  0.172  0.834  0.079  1.0
  O  O15  1  0.758  0.672  0.998  1.0
  O  O16  1  0.997  0.330  0.757  1.0
  O  O17  1  0.077  0.167  0.171  1.0
  O  O18  1  0.004  0.731  0.468  1.0
  O  O19  1  0.482  0.776  0.488  1.0
  O  O20  1  0.487  0.226  0.482  1.0
  O  O21  1  0.467  0.270  0.004  1.0
[/CIF]
.
The compound described by Li2NiSi2O6 crystallizes in the triclinic P1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(10), one O(4), one O(5), and one O(6) atom to form LiO4 tetrahedra that share  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(3), one O(5), one O(6), and one O(9) atom to form LiO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the third Li site, Li(3) is bonded to one O(12), one O(2), one O(7), and one O(8) atom to form LiO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and corners with two equivalent Si(4)O4 tetrahedra. In the fourth Li site, Li(4) is bonded to one O(1), one O(11), one O(7), and one O(8) atom to form LiO4 tetrahedra that share  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and corners with two equivalent Si(4)O4 tetrahedra. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(4), one O(5), and one O(8) atom to form NiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(3)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(4)O4 tetrahedra. In the second Ni site, Ni(2) is bonded to one O(2), one O(3), one O(6), and one O(7) atom to form NiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(5), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(4)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(10), one O(2), one O(6), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(3)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(11), one O(12), one O(3), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra, and corners with two equivalent Si(4)O4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(11), one O(12), one O(4), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Li(4), one Ni(1), and one Si(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(3), one Ni(2), and one Si(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Li(2), one Ni(2), and one Si(3) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(1), one Ni(1), and one Si(4) atom. In the fifth O site, O(5) is bonded to one Li(1), one Li(2), one Ni(1), and one Si(1) atom to form corner-sharing OLi2SiNi tetrahedra. In the sixth O site, O(6) is bonded to one Li(1), one Li(2), one Ni(2), and one Si(2) atom to form corner-sharing OLi2SiNi tetrahedra. In the seventh O site, O(7) is bonded to one Li(3), one Li(4), one Ni(2), and one Si(3) atom to form corner-sharing OLi2SiNi tetrahedra. In the eighth O site, O(8) is bonded to one Li(3), one Li(4), one Ni(1), and one Si(4) atom to form corner-sharing OLi2SiNi tetrahedra. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Li(2), one Si(1), and one Si(2) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Li(1), one Si(1), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Li(4), one Si(3), and one Si(4) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Li(3), one Si(3), and one Si(4) atom. is represented by the CIF card [CIF]
data_Li2Si2NiO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.123
_cell_length_b   10.430
_cell_length_c   5.128
_cell_angle_alpha   104.450
_cell_angle_beta   90.721
_cell_angle_gamma   75.519
_symmetry_Int_Tables_number   1
_cell_volume   256.538
_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
  Li  Li0  1  0.523  0.835  0.913  1.0
  Li  Li1  1  0.115  0.667  0.828  1.0
  Li  Li2  1  0.827  0.335  0.115  1.0
  Li  Li3  1  0.913  0.167  0.523  1.0
  Si  Si4  1  0.171  0.839  0.399  1.0
  Si  Si5  1  0.757  0.667  0.314  1.0
  Si  Si6  1  0.313  0.334  0.757  1.0
  Si  Si7  1  0.398  0.162  0.171  1.0
  Ni  Ni8  1  0.965  0.000  0.965  1.0
  Ni  Ni9  1  0.725  0.501  0.725  1.0
  O  O10  1  0.057  0.992  0.594  1.0
  O  O11  1  0.785  0.516  0.358  1.0
  O  O12  1  0.359  0.485  0.785  1.0
  O  O13  1  0.594  0.010  0.058  1.0
  O  O14  1  0.172  0.834  0.079  1.0
  O  O15  1  0.758  0.672  0.998  1.0
  O  O16  1  0.997  0.330  0.757  1.0
  O  O17  1  0.077  0.167  0.171  1.0
  O  O18  1  0.004  0.731  0.468  1.0
  O  O19  1  0.482  0.776  0.488  1.0
  O  O20  1  0.487  0.226  0.482  1.0
  O  O21  1  0.467  0.270  0.004  1.0
[/CIF]
.