The crystal structure described by Li2CuAsO4 is Chalcostibite-derived structured and crystallizes in the monoclinic P2_1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(1) atoms. In the second Li site, Li(2) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra and corners with four equivalent As(1)O4 tetrahedra. Cu(1) is bonded in a 3-coordinate geometry to one O(1), one O(3), and one O(4) atom. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with four equivalent Li(2)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Li(1), one Cu(1), and one As(1) atom. In the second O site, O(2) is bonded to one Li(1), two equivalent Li(2), and one As(1) atom to form distorted OLi3As tetrahedra that share corners with two equivalent O(2)Li3As tetrahedra, corners with two equivalent O(3)Li2CuAs trigonal pyramids, and  an edgeedge with one O(3)Li2CuAs trigonal pyramid. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Cu(1), and one As(1) atom to form a mixture of distorted edge and corner-sharing OLi2CuAs trigonal pyramids. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(2), one Cu(1), and one As(1) atom. is represented by the CIF file [CIF]
data_Li2CuAsO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.099
_cell_length_b   5.578
_cell_length_c   6.879
_cell_angle_alpha   88.351
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   195.570
_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  0.967  0.088  0.183  1.0
  Li  Li1  1  0.486  0.193  0.486  1.0
  Li  Li2  1  0.986  0.807  0.514  1.0
  Li  Li3  1  0.467  0.912  0.817  1.0
  Cu  Cu4  1  0.549  0.334  0.999  1.0
  Cu  Cu5  1  0.049  0.666  0.001  1.0
  As  As6  1  0.993  0.277  0.733  1.0
  As  As7  1  0.493  0.723  0.267  1.0
  O  O8  1  0.148  0.130  0.925  1.0
  O  O9  1  0.100  0.154  0.521  1.0
  O  O10  1  0.653  0.237  0.745  1.0
  O  O11  1  0.057  0.585  0.735  1.0
  O  O12  1  0.557  0.415  0.265  1.0
  O  O13  1  0.153  0.763  0.255  1.0
  O  O14  1  0.600  0.846  0.479  1.0
  O  O15  1  0.648  0.870  0.075  1.0
[/CIF]
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The crystal structure described by Li2CuAsO4 is Chalcostibite-derived structured and crystallizes in the monoclinic P2_1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(1) atoms. In the second Li site, Li(2) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra and corners with four equivalent As(1)O4 tetrahedra. Cu(1) is bonded in a 3-coordinate geometry to one O(1), one O(3), and one O(4) atom. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with four equivalent Li(2)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Li(1), one Cu(1), and one As(1) atom. In the second O site, O(2) is bonded to one Li(1), two equivalent Li(2), and one As(1) atom to form distorted OLi3As tetrahedra that share corners with two equivalent O(2)Li3As tetrahedra, corners with two equivalent O(3)Li2CuAs trigonal pyramids, and  an edgeedge with one O(3)Li2CuAs trigonal pyramid. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Cu(1), and one As(1) atom to form a mixture of distorted edge and corner-sharing OLi2CuAs trigonal pyramids. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(2), one Cu(1), and one As(1) atom. is represented by the CIF file [CIF]
data_Li2CuAsO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.099
_cell_length_b   5.578
_cell_length_c   6.879
_cell_angle_alpha   88.351
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   195.570
_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  0.967  0.088  0.183  1.0
  Li  Li1  1  0.486  0.193  0.486  1.0
  Li  Li2  1  0.986  0.807  0.514  1.0
  Li  Li3  1  0.467  0.912  0.817  1.0
  Cu  Cu4  1  0.549  0.334  0.999  1.0
  Cu  Cu5  1  0.049  0.666  0.001  1.0
  As  As6  1  0.993  0.277  0.733  1.0
  As  As7  1  0.493  0.723  0.267  1.0
  O  O8  1  0.148  0.130  0.925  1.0
  O  O9  1  0.100  0.154  0.521  1.0
  O  O10  1  0.653  0.237  0.745  1.0
  O  O11  1  0.057  0.585  0.735  1.0
  O  O12  1  0.557  0.415  0.265  1.0
  O  O13  1  0.153  0.763  0.255  1.0
  O  O14  1  0.600  0.846  0.479  1.0
  O  O15  1  0.648  0.870  0.075  1.0
[/CIF]
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