The structure described by Li2CuSiO4 is beta beryllia-derived structured and crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form LiO4 tetrahedra that share corners with two equivalent Cu(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form LiO4 tetrahedra that share corners with four equivalent Li(1)O4 tetrahedra, corners with four equivalent Cu(1)O4 tetrahedra, and corners with four equivalent Si(1)O4 tetrahedra. Cu(1) is bonded to one O(2), one O(3), and two equivalent O(4) atoms to form CuO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Cu(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with four equivalent Li(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, and corners with four equivalent Cu(1)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), two equivalent Li(1), and one Si(1) atom to form distorted OLi3Si tetrahedra that share corners with four equivalent O(2)Li2CuSi tetrahedra, corners with four equivalent O(3)Li2CuSi tetrahedra, and  an edgeedge with one O(1)Li3Si tetrahedra. In the second O site, O(2) is bonded to one Li(1), one Li(2), one Cu(1), and one Si(1) atom to form OLi2CuSi tetrahedra that share corners with four equivalent O(3)Li2CuSi tetrahedra and corners with four equivalent O(1)Li3Si tetrahedra. 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 OLi2CuSi tetrahedra that share corners with four equivalent O(2)Li2CuSi tetrahedra and corners with four equivalent O(1)Li3Si tetrahedra. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), two equivalent Cu(1), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2CuSiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.033
_cell_length_b   6.350
_cell_length_c   10.722
_cell_angle_alpha   87.328
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   342.294
_cell_formula_units_Z   4
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  0.320  0.006  0.587  1.0
  Li  Li1  1  0.180  0.006  0.087  1.0
  Li  Li2  1  0.318  0.761  0.833  1.0
  Li  Li3  1  0.182  0.761  0.333  1.0
  Li  Li4  1  0.818  0.239  0.667  1.0
  Li  Li5  1  0.682  0.239  0.167  1.0
  Li  Li6  1  0.820  0.994  0.913  1.0
  Li  Li7  1  0.680  0.994  0.413  1.0
  Cu  Cu8  1  0.278  0.510  0.585  1.0
  Cu  Cu9  1  0.222  0.510  0.085  1.0
  Cu  Cu10  1  0.778  0.490  0.915  1.0
  Cu  Cu11  1  0.722  0.490  0.415  1.0
  Si  Si12  1  0.818  0.760  0.666  1.0
  Si  Si13  1  0.682  0.760  0.166  1.0
  Si  Si14  1  0.318  0.240  0.834  1.0
  Si  Si15  1  0.182  0.240  0.334  1.0
  O  O16  1  0.715  0.976  0.595  1.0
  O  O17  1  0.785  0.976  0.095  1.0
  O  O18  1  0.708  0.747  0.812  1.0
  O  O19  1  0.149  0.749  0.668  1.0
  O  O20  1  0.792  0.747  0.312  1.0
  O  O21  1  0.351  0.749  0.168  1.0
  O  O22  1  0.710  0.550  0.591  1.0
  O  O23  1  0.790  0.550  0.091  1.0
  O  O24  1  0.210  0.450  0.909  1.0
  O  O25  1  0.290  0.450  0.409  1.0
  O  O26  1  0.649  0.251  0.832  1.0
  O  O27  1  0.208  0.253  0.688  1.0
  O  O28  1  0.851  0.251  0.332  1.0
  O  O29  1  0.292  0.253  0.188  1.0
  O  O30  1  0.215  0.024  0.905  1.0
  O  O31  1  0.285  0.024  0.405  1.0
[/CIF]
.
The structure described by Li2CuSiO4 is beta beryllia-derived structured and crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form LiO4 tetrahedra that share corners with two equivalent Cu(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Li(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form LiO4 tetrahedra that share corners with four equivalent Li(1)O4 tetrahedra, corners with four equivalent Cu(1)O4 tetrahedra, and corners with four equivalent Si(1)O4 tetrahedra. Cu(1) is bonded to one O(2), one O(3), and two equivalent O(4) atoms to form CuO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Cu(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with four equivalent Li(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, and corners with four equivalent Cu(1)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), two equivalent Li(1), and one Si(1) atom to form distorted OLi3Si tetrahedra that share corners with four equivalent O(2)Li2CuSi tetrahedra, corners with four equivalent O(3)Li2CuSi tetrahedra, and  an edgeedge with one O(1)Li3Si tetrahedra. In the second O site, O(2) is bonded to one Li(1), one Li(2), one Cu(1), and one Si(1) atom to form OLi2CuSi tetrahedra that share corners with four equivalent O(3)Li2CuSi tetrahedra and corners with four equivalent O(1)Li3Si tetrahedra. 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 OLi2CuSi tetrahedra that share corners with four equivalent O(2)Li2CuSi tetrahedra and corners with four equivalent O(1)Li3Si tetrahedra. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Li(2), two equivalent Cu(1), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Li2CuSiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.033
_cell_length_b   6.350
_cell_length_c   10.722
_cell_angle_alpha   87.328
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   342.294
_cell_formula_units_Z   4
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  0.320  0.006  0.587  1.0
  Li  Li1  1  0.180  0.006  0.087  1.0
  Li  Li2  1  0.318  0.761  0.833  1.0
  Li  Li3  1  0.182  0.761  0.333  1.0
  Li  Li4  1  0.818  0.239  0.667  1.0
  Li  Li5  1  0.682  0.239  0.167  1.0
  Li  Li6  1  0.820  0.994  0.913  1.0
  Li  Li7  1  0.680  0.994  0.413  1.0
  Cu  Cu8  1  0.278  0.510  0.585  1.0
  Cu  Cu9  1  0.222  0.510  0.085  1.0
  Cu  Cu10  1  0.778  0.490  0.915  1.0
  Cu  Cu11  1  0.722  0.490  0.415  1.0
  Si  Si12  1  0.818  0.760  0.666  1.0
  Si  Si13  1  0.682  0.760  0.166  1.0
  Si  Si14  1  0.318  0.240  0.834  1.0
  Si  Si15  1  0.182  0.240  0.334  1.0
  O  O16  1  0.715  0.976  0.595  1.0
  O  O17  1  0.785  0.976  0.095  1.0
  O  O18  1  0.708  0.747  0.812  1.0
  O  O19  1  0.149  0.749  0.668  1.0
  O  O20  1  0.792  0.747  0.312  1.0
  O  O21  1  0.351  0.749  0.168  1.0
  O  O22  1  0.710  0.550  0.591  1.0
  O  O23  1  0.790  0.550  0.091  1.0
  O  O24  1  0.210  0.450  0.909  1.0
  O  O25  1  0.290  0.450  0.409  1.0
  O  O26  1  0.649  0.251  0.832  1.0
  O  O27  1  0.208  0.253  0.688  1.0
  O  O28  1  0.851  0.251  0.332  1.0
  O  O29  1  0.292  0.253  0.188  1.0
  O  O30  1  0.215  0.024  0.905  1.0
  O  O31  1  0.285  0.024  0.405  1.0
[/CIF]
.