The compound described by Li4Cu2Si3O10 crystallizes in the monoclinic C2/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(3), one O(5), and two equivalent O(2) atoms to form LiO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra, corners with three equivalent Cu(1)O5 trigonal bipyramids,  an edgeedge with one Li(1)O4 tetrahedra, and  an edgeedge with one Cu(1)O5 trigonal bipyramid. In the second Li site, Li(2) is bonded in a distorted pentagonal planar geometry to one O(3), two equivalent O(1), and two equivalent O(4) atoms. Cu(1) is bonded to one O(1), one O(2), one O(3), and two equivalent O(5) atoms to form CuO5 trigonal bipyramids that share  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra,  an edgeedge with one Li(1)O4 tetrahedra, and  an edgeedge with one Cu(1)O5 trigonal bipyramid. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, and corners with four equivalent Cu(1)O5 trigonal bipyramids. In the second Si site, Si(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Cu(1)O5 trigonal bipyramids. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(2), one Cu(1), and one Si(2) atom to form a mixture of distorted edge and corner-sharing OLi2CuSi trigonal pyramids. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li(1), one Cu(1), and one Si(1) atom. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Cu(1), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OLi2CuSi tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Li(2), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Li(1), two equivalent Cu(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Li4Cu2Si3O10
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.387
_cell_length_b   5.387
_cell_length_c   16.247
_cell_angle_alpha   82.871
_cell_angle_beta   82.871
_cell_angle_gamma   61.427
_symmetry_Int_Tables_number   1
_cell_volume   409.748
_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  0.835  0.682  0.947  1.0
  Li  Li1  1  0.584  0.788  0.766  1.0
  Li  Li2  1  0.682  0.835  0.447  1.0
  Li  Li3  1  0.788  0.584  0.266  1.0
  Li  Li4  1  0.212  0.416  0.734  1.0
  Li  Li5  1  0.318  0.165  0.553  1.0
  Li  Li6  1  0.416  0.212  0.234  1.0
  Li  Li7  1  0.165  0.318  0.053  1.0
  Cu  Cu8  1  0.201  0.980  0.918  1.0
  Cu  Cu9  1  0.980  0.201  0.418  1.0
  Cu  Cu10  1  0.020  0.799  0.582  1.0
  Cu  Cu11  1  0.799  0.020  0.082  1.0
  Si  Si12  1  0.656  0.471  0.597  1.0
  Si  Si13  1  0.891  0.109  0.750  1.0
  Si  Si14  1  0.529  0.344  0.903  1.0
  Si  Si15  1  0.471  0.656  0.097  1.0
  Si  Si16  1  0.109  0.891  0.250  1.0
  Si  Si17  1  0.344  0.529  0.403  1.0
  O  O18  1  0.933  0.838  0.705  1.0
  O  O19  1  0.838  0.933  0.205  1.0
  O  O20  1  0.607  0.785  0.566  1.0
  O  O21  1  0.568  0.632  0.887  1.0
  O  O22  1  0.802  0.403  0.688  1.0
  O  O23  1  0.778  0.090  0.959  1.0
  O  O24  1  0.910  0.222  0.541  1.0
  O  O25  1  0.785  0.607  0.066  1.0
  O  O26  1  0.632  0.568  0.387  1.0
  O  O27  1  0.597  0.198  0.812  1.0
  O  O28  1  0.403  0.802  0.188  1.0
  O  O29  1  0.368  0.432  0.613  1.0
  O  O30  1  0.215  0.393  0.934  1.0
  O  O31  1  0.090  0.778  0.459  1.0
  O  O32  1  0.222  0.910  0.041  1.0
  O  O33  1  0.198  0.597  0.312  1.0
  O  O34  1  0.432  0.368  0.113  1.0
  O  O35  1  0.393  0.215  0.434  1.0
  O  O36  1  0.162  0.067  0.795  1.0
  O  O37  1  0.067  0.162  0.295  1.0
[/CIF]
.
The compound described by Li4Cu2Si3O10 crystallizes in the monoclinic C2/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(3), one O(5), and two equivalent O(2) atoms to form LiO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra, corners with three equivalent Cu(1)O5 trigonal bipyramids,  an edgeedge with one Li(1)O4 tetrahedra, and  an edgeedge with one Cu(1)O5 trigonal bipyramid. In the second Li site, Li(2) is bonded in a distorted pentagonal planar geometry to one O(3), two equivalent O(1), and two equivalent O(4) atoms. Cu(1) is bonded to one O(1), one O(2), one O(3), and two equivalent O(5) atoms to form CuO5 trigonal bipyramids that share  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra,  an edgeedge with one Li(1)O4 tetrahedra, and  an edgeedge with one Cu(1)O5 trigonal bipyramid. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra, corners with four equivalent Li(1)O4 tetrahedra, and corners with four equivalent Cu(1)O5 trigonal bipyramids. In the second Si site, Si(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Cu(1)O5 trigonal bipyramids. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(2), one Cu(1), and one Si(2) atom to form a mixture of distorted edge and corner-sharing OLi2CuSi trigonal pyramids. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li(1), one Cu(1), and one Si(1) atom. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Cu(1), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OLi2CuSi tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Li(2), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Li(1), two equivalent Cu(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Li4Cu2Si3O10
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.387
_cell_length_b   5.387
_cell_length_c   16.247
_cell_angle_alpha   82.871
_cell_angle_beta   82.871
_cell_angle_gamma   61.427
_symmetry_Int_Tables_number   1
_cell_volume   409.748
_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  0.835  0.682  0.947  1.0
  Li  Li1  1  0.584  0.788  0.766  1.0
  Li  Li2  1  0.682  0.835  0.447  1.0
  Li  Li3  1  0.788  0.584  0.266  1.0
  Li  Li4  1  0.212  0.416  0.734  1.0
  Li  Li5  1  0.318  0.165  0.553  1.0
  Li  Li6  1  0.416  0.212  0.234  1.0
  Li  Li7  1  0.165  0.318  0.053  1.0
  Cu  Cu8  1  0.201  0.980  0.918  1.0
  Cu  Cu9  1  0.980  0.201  0.418  1.0
  Cu  Cu10  1  0.020  0.799  0.582  1.0
  Cu  Cu11  1  0.799  0.020  0.082  1.0
  Si  Si12  1  0.656  0.471  0.597  1.0
  Si  Si13  1  0.891  0.109  0.750  1.0
  Si  Si14  1  0.529  0.344  0.903  1.0
  Si  Si15  1  0.471  0.656  0.097  1.0
  Si  Si16  1  0.109  0.891  0.250  1.0
  Si  Si17  1  0.344  0.529  0.403  1.0
  O  O18  1  0.933  0.838  0.705  1.0
  O  O19  1  0.838  0.933  0.205  1.0
  O  O20  1  0.607  0.785  0.566  1.0
  O  O21  1  0.568  0.632  0.887  1.0
  O  O22  1  0.802  0.403  0.688  1.0
  O  O23  1  0.778  0.090  0.959  1.0
  O  O24  1  0.910  0.222  0.541  1.0
  O  O25  1  0.785  0.607  0.066  1.0
  O  O26  1  0.632  0.568  0.387  1.0
  O  O27  1  0.597  0.198  0.812  1.0
  O  O28  1  0.403  0.802  0.188  1.0
  O  O29  1  0.368  0.432  0.613  1.0
  O  O30  1  0.215  0.393  0.934  1.0
  O  O31  1  0.090  0.778  0.459  1.0
  O  O32  1  0.222  0.910  0.041  1.0
  O  O33  1  0.198  0.597  0.312  1.0
  O  O34  1  0.432  0.368  0.113  1.0
  O  O35  1  0.393  0.215  0.434  1.0
  O  O36  1  0.162  0.067  0.795  1.0
  O  O37  1  0.067  0.162  0.295  1.0
[/CIF]
.