The material structure described by Li4CuSi2O7 is Stannite-like structured and crystallizes in the monoclinic Cc space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(3)O4 tetrahedra,  a cornercorner with one Cu(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with three equivalent Li(4)O4 tetrahedra, and corners with three equivalent Si(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Cu(1)O4 tetrahedra, corners with three equivalent Li(3)O4 tetrahedra, and corners with three equivalent Si(1)O4 tetrahedra. In the third Li site, Li(3) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, and corners with three equivalent Cu(1)O4 tetrahedra. In the fourth Li site, Li(4) is bonded to one O(1), one O(2), one O(6), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(3)O4 tetrahedra, corners with two equivalent Cu(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and corners with three equivalent Si(2)O4 tetrahedra. Cu(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form CuO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with three equivalent Li(3)O4 tetrahedra, and corners with three equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, 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  a cornercorner with one Cu(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and corners with three equivalent Li(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with three equivalent Li(4)O4 tetrahedra, and corners with three equivalent Cu(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(3) is bonded to one Li(1), one Li(2), one Li(3), and one Si(1) atom to form OLi3Si tetrahedra that share  a cornercorner with one O(6)Li2CuSi tetrahedra,  a cornercorner with one O(7)Li2CuSi tetrahedra, corners with two equivalent O(5)Li2CuSi tetrahedra, corners with two equivalent O(1)Li2Si2 tetrahedra, corners with three equivalent O(4)Li2CuSi tetrahedra, and corners with three equivalent O(2)Li3Si tetrahedra. In the second O site, O(4) is bonded to one Li(2), one Li(3), one Cu(1), and one Si(1) atom to form OLi2CuSi tetrahedra that share  a cornercorner with one O(7)Li2CuSi tetrahedra,  a cornercorner with one O(1)Li2Si2 tetrahedra, corners with two equivalent O(6)Li2CuSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, corners with three equivalent O(5)Li2CuSi tetrahedra, and corners with three equivalent O(3)Li3Si tetrahedra. In the third O site, O(5) is bonded to one Li(2), one Li(3), one Cu(1), and one Si(2) atom to form distorted OLi2CuSi tetrahedra that share  a cornercorner with one O(1)Li2Si2 tetrahedra,  a cornercorner with one O(2)Li3Si tetrahedra, corners with two equivalent O(7)Li2CuSi tetrahedra, corners with two equivalent O(3)Li3Si tetrahedra, corners with three equivalent O(4)Li2CuSi tetrahedra, and corners with three equivalent O(6)Li2CuSi tetrahedra. In the fourth O site, O(6) is bonded to one Li(3), one Li(4), one Cu(1), and one Si(2) atom to form OLi2CuSi tetrahedra that share  a cornercorner with one O(2)Li3Si tetrahedra,  a cornercorner with one O(3)Li3Si tetrahedra, corners with two equivalent O(4)Li2CuSi tetrahedra, corners with two equivalent O(1)Li2Si2 tetrahedra, corners with three equivalent O(5)Li2CuSi tetrahedra, and corners with three equivalent O(7)Li2CuSi tetrahedra. In the fifth O site, O(7) is bonded to one Li(1), one Li(4), one Cu(1), and one Si(2) atom to form OLi2CuSi tetrahedra that share  a cornercorner with one O(4)Li2CuSi tetrahedra,  a cornercorner with one O(3)Li3Si tetrahedra, corners with two equivalent O(5)Li2CuSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, corners with three equivalent O(6)Li2CuSi tetrahedra, and corners with three equivalent O(1)Li2Si2 tetrahedra. In the sixth O site, O(1) is bonded to one Li(1), one Li(4), one Si(1), and one Si(2) atom to form OLi2Si2 tetrahedra that share  a cornercorner with one O(4)Li2CuSi tetrahedra,  a cornercorner with one O(5)Li2CuSi tetrahedra, corners with two equivalent O(6)Li2CuSi tetrahedra, corners with two equivalent O(3)Li3Si tetrahedra, corners with three equivalent O(7)Li2CuSi tetrahedra, and corners with three equivalent O(2)Li3Si tetrahedra. In the seventh O site, O(2) is bonded to one Li(1), one Li(2), one Li(4), and one Si(1) atom to form OLi3Si tetrahedra that share  a cornercorner with one O(5)Li2CuSi tetrahedra,  a cornercorner with one O(6)Li2CuSi tetrahedra, corners with two equivalent O(4)Li2CuSi tetrahedra, corners with two equivalent O(7)Li2CuSi tetrahedra, corners with three equivalent O(1)Li2Si2 tetrahedra, and corners with three equivalent O(3)Li3Si tetrahedra. is represented by the CIF card [CIF]
data_Li4CuSi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.136
_cell_length_b   7.136
_cell_length_c   8.154
_cell_angle_alpha   86.666
_cell_angle_beta   86.666
_cell_angle_gamma   44.883
_symmetry_Int_Tables_number   1
_cell_volume   292.461
_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  0.414  0.735  0.123  1.0
  Li  Li1  1  0.735  0.414  0.623  1.0
  Li  Li2  1  0.536  0.880  0.406  1.0
  Li  Li3  1  0.880  0.536  0.906  1.0
  Li  Li4  1  0.429  0.128  0.054  1.0
  Li  Li5  1  0.128  0.429  0.554  1.0
  Li  Li6  1  0.815  0.182  0.981  1.0
  Li  Li7  1  0.182  0.815  0.481  1.0
  Cu  Cu8  1  0.017  0.683  0.203  1.0
  Cu  Cu9  1  0.683  0.017  0.703  1.0
  Si  Si10  1  0.967  0.309  0.260  1.0
  Si  Si11  1  0.309  0.967  0.760  1.0
  Si  Si12  1  0.600  0.250  0.330  1.0
  Si  Si13  1  0.250  0.600  0.830  1.0
  O  O14  1  0.843  0.219  0.393  1.0
  O  O15  1  0.219  0.843  0.893  1.0
  O  O16  1  0.792  0.428  0.095  1.0
  O  O17  1  0.428  0.792  0.595  1.0
  O  O18  1  0.281  0.049  0.227  1.0
  O  O19  1  0.049  0.281  0.727  1.0
  O  O20  1  0.914  0.541  0.358  1.0
  O  O21  1  0.541  0.914  0.858  1.0
  O  O22  1  0.532  0.143  0.481  1.0
  O  O23  1  0.143  0.532  0.981  1.0
  O  O24  1  0.706  0.071  0.166  1.0
  O  O25  1  0.071  0.706  0.666  1.0
  O  O26  1  0.337  0.567  0.292  1.0
  O  O27  1  0.567  0.337  0.792  1.0
[/CIF]
.
The material structure described by Li4CuSi2O7 is Stannite-like structured and crystallizes in the monoclinic Cc space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(3)O4 tetrahedra,  a cornercorner with one Cu(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with three equivalent Li(4)O4 tetrahedra, and corners with three equivalent Si(1)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(4)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Cu(1)O4 tetrahedra, corners with three equivalent Li(3)O4 tetrahedra, and corners with three equivalent Si(1)O4 tetrahedra. In the third Li site, Li(3) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Li(4)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with three equivalent Li(2)O4 tetrahedra, and corners with three equivalent Cu(1)O4 tetrahedra. In the fourth Li site, Li(4) is bonded to one O(1), one O(2), one O(6), and one O(7) atom to form LiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Li(3)O4 tetrahedra, corners with two equivalent Cu(1)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and corners with three equivalent Si(2)O4 tetrahedra. Cu(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form CuO4 tetrahedra that share  a cornercorner with one Li(1)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with three equivalent Li(3)O4 tetrahedra, and corners with three equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, 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  a cornercorner with one Cu(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with three equivalent Li(1)O4 tetrahedra, and corners with three equivalent Li(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Li(2)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with three equivalent Li(4)O4 tetrahedra, and corners with three equivalent Cu(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(3) is bonded to one Li(1), one Li(2), one Li(3), and one Si(1) atom to form OLi3Si tetrahedra that share  a cornercorner with one O(6)Li2CuSi tetrahedra,  a cornercorner with one O(7)Li2CuSi tetrahedra, corners with two equivalent O(5)Li2CuSi tetrahedra, corners with two equivalent O(1)Li2Si2 tetrahedra, corners with three equivalent O(4)Li2CuSi tetrahedra, and corners with three equivalent O(2)Li3Si tetrahedra. In the second O site, O(4) is bonded to one Li(2), one Li(3), one Cu(1), and one Si(1) atom to form OLi2CuSi tetrahedra that share  a cornercorner with one O(7)Li2CuSi tetrahedra,  a cornercorner with one O(1)Li2Si2 tetrahedra, corners with two equivalent O(6)Li2CuSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, corners with three equivalent O(5)Li2CuSi tetrahedra, and corners with three equivalent O(3)Li3Si tetrahedra. In the third O site, O(5) is bonded to one Li(2), one Li(3), one Cu(1), and one Si(2) atom to form distorted OLi2CuSi tetrahedra that share  a cornercorner with one O(1)Li2Si2 tetrahedra,  a cornercorner with one O(2)Li3Si tetrahedra, corners with two equivalent O(7)Li2CuSi tetrahedra, corners with two equivalent O(3)Li3Si tetrahedra, corners with three equivalent O(4)Li2CuSi tetrahedra, and corners with three equivalent O(6)Li2CuSi tetrahedra. In the fourth O site, O(6) is bonded to one Li(3), one Li(4), one Cu(1), and one Si(2) atom to form OLi2CuSi tetrahedra that share  a cornercorner with one O(2)Li3Si tetrahedra,  a cornercorner with one O(3)Li3Si tetrahedra, corners with two equivalent O(4)Li2CuSi tetrahedra, corners with two equivalent O(1)Li2Si2 tetrahedra, corners with three equivalent O(5)Li2CuSi tetrahedra, and corners with three equivalent O(7)Li2CuSi tetrahedra. In the fifth O site, O(7) is bonded to one Li(1), one Li(4), one Cu(1), and one Si(2) atom to form OLi2CuSi tetrahedra that share  a cornercorner with one O(4)Li2CuSi tetrahedra,  a cornercorner with one O(3)Li3Si tetrahedra, corners with two equivalent O(5)Li2CuSi tetrahedra, corners with two equivalent O(2)Li3Si tetrahedra, corners with three equivalent O(6)Li2CuSi tetrahedra, and corners with three equivalent O(1)Li2Si2 tetrahedra. In the sixth O site, O(1) is bonded to one Li(1), one Li(4), one Si(1), and one Si(2) atom to form OLi2Si2 tetrahedra that share  a cornercorner with one O(4)Li2CuSi tetrahedra,  a cornercorner with one O(5)Li2CuSi tetrahedra, corners with two equivalent O(6)Li2CuSi tetrahedra, corners with two equivalent O(3)Li3Si tetrahedra, corners with three equivalent O(7)Li2CuSi tetrahedra, and corners with three equivalent O(2)Li3Si tetrahedra. In the seventh O site, O(2) is bonded to one Li(1), one Li(2), one Li(4), and one Si(1) atom to form OLi3Si tetrahedra that share  a cornercorner with one O(5)Li2CuSi tetrahedra,  a cornercorner with one O(6)Li2CuSi tetrahedra, corners with two equivalent O(4)Li2CuSi tetrahedra, corners with two equivalent O(7)Li2CuSi tetrahedra, corners with three equivalent O(1)Li2Si2 tetrahedra, and corners with three equivalent O(3)Li3Si tetrahedra. is represented by the CIF card [CIF]
data_Li4CuSi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.136
_cell_length_b   7.136
_cell_length_c   8.154
_cell_angle_alpha   86.666
_cell_angle_beta   86.666
_cell_angle_gamma   44.883
_symmetry_Int_Tables_number   1
_cell_volume   292.461
_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  0.414  0.735  0.123  1.0
  Li  Li1  1  0.735  0.414  0.623  1.0
  Li  Li2  1  0.536  0.880  0.406  1.0
  Li  Li3  1  0.880  0.536  0.906  1.0
  Li  Li4  1  0.429  0.128  0.054  1.0
  Li  Li5  1  0.128  0.429  0.554  1.0
  Li  Li6  1  0.815  0.182  0.981  1.0
  Li  Li7  1  0.182  0.815  0.481  1.0
  Cu  Cu8  1  0.017  0.683  0.203  1.0
  Cu  Cu9  1  0.683  0.017  0.703  1.0
  Si  Si10  1  0.967  0.309  0.260  1.0
  Si  Si11  1  0.309  0.967  0.760  1.0
  Si  Si12  1  0.600  0.250  0.330  1.0
  Si  Si13  1  0.250  0.600  0.830  1.0
  O  O14  1  0.843  0.219  0.393  1.0
  O  O15  1  0.219  0.843  0.893  1.0
  O  O16  1  0.792  0.428  0.095  1.0
  O  O17  1  0.428  0.792  0.595  1.0
  O  O18  1  0.281  0.049  0.227  1.0
  O  O19  1  0.049  0.281  0.727  1.0
  O  O20  1  0.914  0.541  0.358  1.0
  O  O21  1  0.541  0.914  0.858  1.0
  O  O22  1  0.532  0.143  0.481  1.0
  O  O23  1  0.143  0.532  0.981  1.0
  O  O24  1  0.706  0.071  0.166  1.0
  O  O25  1  0.071  0.706  0.666  1.0
  O  O26  1  0.337  0.567  0.292  1.0
  O  O27  1  0.567  0.337  0.792  1.0
[/CIF]
.