The compound described by Ag2SnSe3 is Enargite-like structured and crystallizes in the monoclinic Cc space group. There are eight inequivalent Ag sites. In the first Ag site, Ag(1) is bonded to one Se(11), one Se(12), one Se(2), and one Se(8) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(3)Se4 tetrahedra,  a cornercorner with one Ag(4)Se4 tetrahedra,  a cornercorner with one Ag(7)Se4 tetrahedra,  a cornercorner with one Ag(8)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra,  a cornercorner with one Sn(4)Se4 tetrahedra, corners with three equivalent Ag(2)Se4 tetrahedra, and corners with three equivalent Sn(1)Se4 tetrahedra. In the second Ag site, Ag(2) is bonded to one Se(11), one Se(2), one Se(8), and one Se(9) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(3)Se4 tetrahedra,  a cornercorner with one Ag(4)Se4 tetrahedra,  a cornercorner with one Ag(7)Se4 tetrahedra,  a cornercorner with one Ag(8)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra,  a cornercorner with one Sn(4)Se4 tetrahedra, corners with three equivalent Ag(1)Se4 tetrahedra, and corners with three equivalent Sn(1)Se4 tetrahedra. In the third Ag site, Ag(3) is bonded to one Se(10), one Se(6), one Se(7), and one Se(8) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(1)Se4 tetrahedra,  a cornercorner with one Ag(2)Se4 tetrahedra,  a cornercorner with one Ag(5)Se4 tetrahedra,  a cornercorner with one Ag(6)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(3)Se4 tetrahedra, corners with three equivalent Ag(4)Se4 tetrahedra, and corners with three equivalent Sn(2)Se4 tetrahedra. In the fourth Ag site, Ag(4) is bonded to one Se(10), one Se(11), one Se(6), and one Se(7) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(1)Se4 tetrahedra,  a cornercorner with one Ag(2)Se4 tetrahedra,  a cornercorner with one Ag(5)Se4 tetrahedra,  a cornercorner with one Ag(6)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(3)Se4 tetrahedra, corners with three equivalent Ag(3)Se4 tetrahedra, and corners with three equivalent Sn(2)Se4 tetrahedra. In the fifth Ag site, Ag(5) is bonded to one Se(3), one Se(4), one Se(5), and one Se(7) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(3)Se4 tetrahedra,  a cornercorner with one Ag(4)Se4 tetrahedra,  a cornercorner with one Ag(7)Se4 tetrahedra,  a cornercorner with one Ag(8)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra,  a cornercorner with one Sn(4)Se4 tetrahedra, corners with three equivalent Ag(6)Se4 tetrahedra, and corners with three equivalent Sn(3)Se4 tetrahedra. In the sixth Ag site, Ag(6) is bonded to one Se(10), one Se(3), one Se(4), and one Se(5) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(3)Se4 tetrahedra,  a cornercorner with one Ag(4)Se4 tetrahedra,  a cornercorner with one Ag(7)Se4 tetrahedra,  a cornercorner with one Ag(8)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra,  a cornercorner with one Sn(4)Se4 tetrahedra, corners with three equivalent Ag(5)Se4 tetrahedra, and corners with three equivalent Sn(3)Se4 tetrahedra. In the seventh Ag site, Ag(7) is bonded to one Se(1), one Se(12), one Se(4), and one Se(9) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(1)Se4 tetrahedra,  a cornercorner with one Ag(2)Se4 tetrahedra,  a cornercorner with one Ag(5)Se4 tetrahedra,  a cornercorner with one Ag(6)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(3)Se4 tetrahedra, corners with three equivalent Ag(8)Se4 tetrahedra, and corners with three equivalent Sn(4)Se4 tetrahedra. In the eighth Ag site, Ag(8) is bonded to one Se(1), one Se(12), one Se(5), and one Se(9) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(1)Se4 tetrahedra,  a cornercorner with one Ag(2)Se4 tetrahedra,  a cornercorner with one Ag(5)Se4 tetrahedra,  a cornercorner with one Ag(6)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(3)Se4 tetrahedra, corners with three equivalent Ag(7)Se4 tetrahedra, and corners with three equivalent Sn(4)Se4 tetrahedra. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one Se(1), one Se(11), one Se(2), and one Se(8) atom to form SnSe4 tetrahedra that share  a cornercorner with one Ag(3)Se4 tetrahedra,  a cornercorner with one Ag(4)Se4 tetrahedra,  a cornercorner with one Ag(7)Se4 tetrahedra,  a cornercorner with one Ag(8)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra,  a cornercorner with one Sn(4)Se4 tetrahedra, corners with three equivalent Ag(1)Se4 tetrahedra, and corners with three equivalent Ag(2)Se4 tetrahedra. In the second Sn site, Sn(2) is bonded to one Se(10), one Se(2), one Se(6), and one Se(7) atom to form SnSe4 tetrahedra that share  a cornercorner with one Ag(1)Se4 tetrahedra,  a cornercorner with one Ag(2)Se4 tetrahedra,  a cornercorner with one Ag(5)Se4 tetrahedra,  a cornercorner with one Ag(6)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(3)Se4 tetrahedra, corners with three equivalent Ag(3)Se4 tetrahedra, and corners with three equivalent Ag(4)Se4 tetrahedra. In the third Sn site, Sn(3) is bonded to one Se(3), one Se(4), one Se(5), and one Se(6) atom to form SnSe4 tetrahedra that share  a cornercorner with one Ag(3)Se4 tetrahedra,  a cornercorner with one Ag(4)Se4 tetrahedra,  a cornercorner with one Ag(7)Se4 tetrahedra,  a cornercorner with one Ag(8)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra,  a cornercorner with one Sn(4)Se4 tetrahedra, corners with three equivalent Ag(5)Se4 tetrahedra, and corners with three equivalent Ag(6)Se4 tetrahedra. In the fourth Sn site, Sn(4) is bonded to one Se(1), one Se(12), one Se(3), and one Se(9) atom to form SnSe4 tetrahedra that share  a cornercorner with one Ag(1)Se4 tetrahedra,  a cornercorner with one Ag(2)Se4 tetrahedra,  a cornercorner with one Ag(5)Se4 tetrahedra,  a cornercorner with one Ag(6)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(3)Se4 tetrahedra, corners with three equivalent Ag(7)Se4 tetrahedra, and corners with three equivalent Ag(8)Se4 tetrahedra. There are twelve inequivalent Se sites. In the first Se site, Se(1) is bonded to one Ag(7), one Ag(8), one Sn(1), and one Sn(4) atom to form SeAg2Sn2 tetrahedra that share  a cornercorner with one Se(2)Ag2Sn2 tetrahedra,  a cornercorner with one Se(3)Ag2Sn2 tetrahedra,  a cornercorner with one Se(11)Ag3Sn tetrahedra,  a cornercorner with one Se(4)Ag3Sn tetrahedra,  a cornercorner with one Se(5)Ag3Sn tetrahedra,  a cornercorner with one Se(8)Ag3Sn tetrahedra, corners with three equivalent Se(12)Ag3Sn tetrahedra, and corners with three equivalent Se(9)Ag3Sn tetrahedra. In the second Se site, Se(2) is bonded to one Ag(1), one Ag(2), one Sn(1), and one Sn(2) atom to form SeAg2Sn2 tetrahedra that share  a cornercorner with one Se(1)Ag2Sn2 tetrahedra,  a cornercorner with one Se(6)Ag2Sn2 tetrahedra,  a cornercorner with one Se(10)Ag3Sn tetrahedra,  a cornercorner with one Se(12)Ag3Sn tetrahedra,  a cornercorner with one Se(7)Ag3Sn tetrahedra,  a cornercorner with one Se(9)Ag3Sn tetrahedra, corners with three equivalent Se(11)Ag3Sn tetrahedra, and corners with three equivalent Se(8)Ag3Sn tetrahedra. In the third Se site, Se(3) is bonded to one Ag(5), one Ag(6), one Sn(3), and one Sn(4) atom to form SeAg2Sn2 tetrahedra that share  a cornercorner with one Se(1)Ag2Sn2 tetrahedra,  a cornercorner with one Se(6)Ag2Sn2 tetrahedra,  a cornercorner with one Se(10)Ag3Sn tetrahedra,  a cornercorner with one Se(12)Ag3Sn tetrahedra,  a cornercorner with one Se(7)Ag3Sn tetrahedra,  a cornercorner with one Se(9)Ag3Sn tetrahedra, corners with three equivalent Se(4)Ag3Sn tetrahedra, and corners with three equivalent Se(5)Ag3Sn tetrahedra. In the fourth Se site, Se(4) is bonded to one Ag(5), one Ag(6), one Ag(7), and one Sn(3) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(1)Ag2Sn2 tetrahedra,  a cornercorner with one Se(6)Ag2Sn2 tetrahedra,  a cornercorner with one Se(10)Ag3Sn tetrahedra,  a cornercorner with one Se(12)Ag3Sn tetrahedra,  a cornercorner with one Se(7)Ag3Sn tetrahedra,  a cornercorner with one Se(9)Ag3Sn tetrahedra, corners with three equivalent Se(3)Ag2Sn2 tetrahedra, and corners with three equivalent Se(5)Ag3Sn tetrahedra. In the fifth Se site, Se(5) is bonded to one Ag(5), one Ag(6), one Ag(8), and one Sn(3) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(1)Ag2Sn2 tetrahedra,  a cornercorner with one Se(6)Ag2Sn2 tetrahedra,  a cornercorner with one Se(10)Ag3Sn tetrahedra,  a cornercorner with one Se(12)Ag3Sn tetrahedra,  a cornercorner with one Se(7)Ag3Sn tetrahedra,  a cornercorner with one Se(9)Ag3Sn tetrahedra, corners with three equivalent Se(3)Ag2Sn2 tetrahedra, and corners with three equivalent Se(4)Ag3Sn tetrahedra. In the sixth Se site, Se(6) is bonded to one Ag(3), one Ag(4), one Sn(2), and one Sn(3) atom to form SeAg2Sn2 tetrahedra that share  a cornercorner with one Se(2)Ag2Sn2 tetrahedra,  a cornercorner with one Se(3)Ag2Sn2 tetrahedra,  a cornercorner with one Se(11)Ag3Sn tetrahedra,  a cornercorner with one Se(4)Ag3Sn tetrahedra,  a cornercorner with one Se(5)Ag3Sn tetrahedra,  a cornercorner with one Se(8)Ag3Sn tetrahedra, corners with three equivalent Se(10)Ag3Sn tetrahedra, and corners with three equivalent Se(7)Ag3Sn tetrahedra. In the seventh Se site, Se(7) is bonded to one Ag(3), one Ag(4), one Ag(5), and one Sn(2) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(2)Ag2Sn2 tetrahedra,  a cornercorner with one Se(3)Ag2Sn2 tetrahedra,  a cornercorner with one Se(11)Ag3Sn tetrahedra,  a cornercorner with one Se(4)Ag3Sn tetrahedra,  a cornercorner with one Se(5)Ag3Sn tetrahedra,  a cornercorner with one Se(8)Ag3Sn tetrahedra, corners with three equivalent Se(6)Ag2Sn2 tetrahedra, and corners with three equivalent Se(10)Ag3Sn tetrahedra. In the eighth Se site, Se(8) is bonded to one Ag(1), one Ag(2), one Ag(3), and one Sn(1) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(1)Ag2Sn2 tetrahedra,  a cornercorner with one Se(6)Ag2Sn2 tetrahedra,  a cornercorner with one Se(10)Ag3Sn tetrahedra,  a cornercorner with one Se(12)Ag3Sn tetrahedra,  a cornercorner with one Se(7)Ag3Sn tetrahedra,  a cornercorner with one Se(9)Ag3Sn tetrahedra, corners with three equivalent Se(2)Ag2Sn2 tetrahedra, and corners with three equivalent Se(11)Ag3Sn tetrahedra. In the ninth Se site, Se(9) is bonded to one Ag(2), one Ag(7), one Ag(8), and one Sn(4) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(2)Ag2Sn2 tetrahedra,  a cornercorner with one Se(3)Ag2Sn2 tetrahedra,  a cornercorner with one Se(11)Ag3Sn tetrahedra,  a cornercorner with one Se(4)Ag3Sn tetrahedra,  a cornercorner with one Se(5)Ag3Sn tetrahedra,  a cornercorner with one Se(8)Ag3Sn tetrahedra, corners with three equivalent Se(1)Ag2Sn2 tetrahedra, and corners with three equivalent Se(12)Ag3Sn tetrahedra. In the tenth Se site, Se(10) is bonded to one Ag(3), one Ag(4), one Ag(6), and one Sn(2) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(2)Ag2Sn2 tetrahedra,  a cornercorner with one Se(3)Ag2Sn2 tetrahedra,  a cornercorner with one Se(11)Ag3Sn tetrahedra,  a cornercorner with one Se(4)Ag3Sn tetrahedra,  a cornercorner with one Se(5)Ag3Sn tetrahedra,  a cornercorner with one Se(8)Ag3Sn tetrahedra, corners with three equivalent Se(6)Ag2Sn2 tetrahedra, and corners with three equivalent Se(7)Ag3Sn tetrahedra. In the eleventh Se site, Se(11) is bonded to one Ag(1), one Ag(2), one Ag(4), and one Sn(1) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(1)Ag2Sn2 tetrahedra,  a cornercorner with one Se(6)Ag2Sn2 tetrahedra,  a cornercorner with one Se(10)Ag3Sn tetrahedra,  a cornercorner with one Se(12)Ag3Sn tetrahedra,  a cornercorner with one Se(7)Ag3Sn tetrahedra,  a cornercorner with one Se(9)Ag3Sn tetrahedra, corners with three equivalent Se(2)Ag2Sn2 tetrahedra, and corners with three equivalent Se(8)Ag3Sn tetrahedra. In the twelfth Se site, Se(12) is bonded to one Ag(1), one Ag(7), one Ag(8), and one Sn(4) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(2)Ag2Sn2 tetrahedra,  a cornercorner with one Se(3)Ag2Sn2 tetrahedra,  a cornercorner with one Se(11)Ag3Sn tetrahedra,  a cornercorner with one Se(4)Ag3Sn tetrahedra,  a cornercorner with one Se(5)Ag3Sn tetrahedra,  a cornercorner with one Se(8)Ag3Sn tetrahedra, corners with three equivalent Se(1)Ag2Sn2 tetrahedra, and corners with three equivalent Se(9)Ag3Sn tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ag2SnSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.403
_cell_length_b   7.403
_cell_length_c   28.120
_cell_angle_alpha   87.069
_cell_angle_beta   87.069
_cell_angle_gamma   119.496
_symmetry_Int_Tables_number   1
_cell_volume   1334.285
_cell_formula_units_Z   8
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
  Ag  Ag0  1  0.841  0.693  0.988  1.0
  Ag  Ag1  1  0.693  0.841  0.488  1.0
  Ag  Ag2  1  0.528  0.025  0.984  1.0
  Ag  Ag3  1  0.025  0.528  0.484  1.0
  Ag  Ag4  1  0.881  0.371  0.861  1.0
  Ag  Ag5  1  0.371  0.881  0.361  1.0
  Ag  Ag6  1  0.222  0.057  0.860  1.0
  Ag  Ag7  1  0.057  0.222  0.360  1.0
  Ag  Ag8  1  0.902  0.097  0.738  1.0
  Ag  Ag9  1  0.097  0.902  0.238  1.0
  Ag  Ag10  1  0.600  0.442  0.733  1.0
  Ag  Ag11  1  0.442  0.600  0.233  1.0
  Ag  Ag12  1  0.638  0.127  0.607  1.0
  Ag  Ag13  1  0.127  0.638  0.107  1.0
  Ag  Ag14  1  0.296  0.468  0.612  1.0
  Ag  Ag15  1  0.468  0.296  0.112  1.0
  Sn  Sn16  1  0.161  0.328  0.980  1.0
  Sn  Sn17  1  0.328  0.161  0.480  1.0
  Sn  Sn18  1  0.551  0.704  0.855  1.0
  Sn  Sn19  1  0.704  0.551  0.355  1.0
  Sn  Sn20  1  0.277  0.762  0.730  1.0
  Sn  Sn21  1  0.762  0.277  0.230  1.0
  Sn  Sn22  1  0.972  0.790  0.606  1.0
  Sn  Sn23  1  0.790  0.972  0.106  1.0
  Se  Se24  1  0.312  0.145  0.575  1.0
  Se  Se25  1  0.145  0.312  0.075  1.0
  Se  Se26  1  0.506  0.679  0.950  1.0
  Se  Se27  1  0.679  0.506  0.450  1.0
  Se  Se28  1  0.954  0.786  0.701  1.0
  Se  Se29  1  0.786  0.954  0.201  1.0
  Se  Se30  1  0.592  0.107  0.701  1.0
  Se  Se31  1  0.107  0.592  0.201  1.0
  Se  Se32  1  0.260  0.431  0.706  1.0
  Se  Se33  1  0.431  0.260  0.206  1.0
  Se  Se34  1  0.227  0.726  0.825  1.0
  Se  Se35  1  0.726  0.227  0.325  1.0
  Se  Se36  1  0.883  0.042  0.831  1.0
  Se  Se37  1  0.042  0.883  0.331  1.0
  Se  Se38  1  0.864  0.374  0.954  1.0
  Se  Se39  1  0.374  0.864  0.454  1.0
  Se  Se40  1  0.979  0.476  0.577  1.0
  Se  Se41  1  0.476  0.979  0.077  1.0
  Se  Se42  1  0.567  0.394  0.827  1.0
  Se  Se43  1  0.394  0.567  0.327  1.0
  Se  Se44  1  0.192  0.023  0.954  1.0
  Se  Se45  1  0.023  0.192  0.454  1.0
  Se  Se46  1  0.654  0.800  0.581  1.0
  Se  Se47  1  0.800  0.654  0.081  1.0
[/CIF]
.
The compound described by Ag2SnSe3 is Enargite-like structured and crystallizes in the monoclinic Cc space group. There are eight inequivalent Ag sites. In the first Ag site, Ag(1) is bonded to one Se(11), one Se(12), one Se(2), and one Se(8) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(3)Se4 tetrahedra,  a cornercorner with one Ag(4)Se4 tetrahedra,  a cornercorner with one Ag(7)Se4 tetrahedra,  a cornercorner with one Ag(8)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra,  a cornercorner with one Sn(4)Se4 tetrahedra, corners with three equivalent Ag(2)Se4 tetrahedra, and corners with three equivalent Sn(1)Se4 tetrahedra. In the second Ag site, Ag(2) is bonded to one Se(11), one Se(2), one Se(8), and one Se(9) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(3)Se4 tetrahedra,  a cornercorner with one Ag(4)Se4 tetrahedra,  a cornercorner with one Ag(7)Se4 tetrahedra,  a cornercorner with one Ag(8)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra,  a cornercorner with one Sn(4)Se4 tetrahedra, corners with three equivalent Ag(1)Se4 tetrahedra, and corners with three equivalent Sn(1)Se4 tetrahedra. In the third Ag site, Ag(3) is bonded to one Se(10), one Se(6), one Se(7), and one Se(8) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(1)Se4 tetrahedra,  a cornercorner with one Ag(2)Se4 tetrahedra,  a cornercorner with one Ag(5)Se4 tetrahedra,  a cornercorner with one Ag(6)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(3)Se4 tetrahedra, corners with three equivalent Ag(4)Se4 tetrahedra, and corners with three equivalent Sn(2)Se4 tetrahedra. In the fourth Ag site, Ag(4) is bonded to one Se(10), one Se(11), one Se(6), and one Se(7) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(1)Se4 tetrahedra,  a cornercorner with one Ag(2)Se4 tetrahedra,  a cornercorner with one Ag(5)Se4 tetrahedra,  a cornercorner with one Ag(6)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(3)Se4 tetrahedra, corners with three equivalent Ag(3)Se4 tetrahedra, and corners with three equivalent Sn(2)Se4 tetrahedra. In the fifth Ag site, Ag(5) is bonded to one Se(3), one Se(4), one Se(5), and one Se(7) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(3)Se4 tetrahedra,  a cornercorner with one Ag(4)Se4 tetrahedra,  a cornercorner with one Ag(7)Se4 tetrahedra,  a cornercorner with one Ag(8)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra,  a cornercorner with one Sn(4)Se4 tetrahedra, corners with three equivalent Ag(6)Se4 tetrahedra, and corners with three equivalent Sn(3)Se4 tetrahedra. In the sixth Ag site, Ag(6) is bonded to one Se(10), one Se(3), one Se(4), and one Se(5) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(3)Se4 tetrahedra,  a cornercorner with one Ag(4)Se4 tetrahedra,  a cornercorner with one Ag(7)Se4 tetrahedra,  a cornercorner with one Ag(8)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra,  a cornercorner with one Sn(4)Se4 tetrahedra, corners with three equivalent Ag(5)Se4 tetrahedra, and corners with three equivalent Sn(3)Se4 tetrahedra. In the seventh Ag site, Ag(7) is bonded to one Se(1), one Se(12), one Se(4), and one Se(9) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(1)Se4 tetrahedra,  a cornercorner with one Ag(2)Se4 tetrahedra,  a cornercorner with one Ag(5)Se4 tetrahedra,  a cornercorner with one Ag(6)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(3)Se4 tetrahedra, corners with three equivalent Ag(8)Se4 tetrahedra, and corners with three equivalent Sn(4)Se4 tetrahedra. In the eighth Ag site, Ag(8) is bonded to one Se(1), one Se(12), one Se(5), and one Se(9) atom to form AgSe4 tetrahedra that share  a cornercorner with one Ag(1)Se4 tetrahedra,  a cornercorner with one Ag(2)Se4 tetrahedra,  a cornercorner with one Ag(5)Se4 tetrahedra,  a cornercorner with one Ag(6)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(3)Se4 tetrahedra, corners with three equivalent Ag(7)Se4 tetrahedra, and corners with three equivalent Sn(4)Se4 tetrahedra. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one Se(1), one Se(11), one Se(2), and one Se(8) atom to form SnSe4 tetrahedra that share  a cornercorner with one Ag(3)Se4 tetrahedra,  a cornercorner with one Ag(4)Se4 tetrahedra,  a cornercorner with one Ag(7)Se4 tetrahedra,  a cornercorner with one Ag(8)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra,  a cornercorner with one Sn(4)Se4 tetrahedra, corners with three equivalent Ag(1)Se4 tetrahedra, and corners with three equivalent Ag(2)Se4 tetrahedra. In the second Sn site, Sn(2) is bonded to one Se(10), one Se(2), one Se(6), and one Se(7) atom to form SnSe4 tetrahedra that share  a cornercorner with one Ag(1)Se4 tetrahedra,  a cornercorner with one Ag(2)Se4 tetrahedra,  a cornercorner with one Ag(5)Se4 tetrahedra,  a cornercorner with one Ag(6)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(3)Se4 tetrahedra, corners with three equivalent Ag(3)Se4 tetrahedra, and corners with three equivalent Ag(4)Se4 tetrahedra. In the third Sn site, Sn(3) is bonded to one Se(3), one Se(4), one Se(5), and one Se(6) atom to form SnSe4 tetrahedra that share  a cornercorner with one Ag(3)Se4 tetrahedra,  a cornercorner with one Ag(4)Se4 tetrahedra,  a cornercorner with one Ag(7)Se4 tetrahedra,  a cornercorner with one Ag(8)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra,  a cornercorner with one Sn(4)Se4 tetrahedra, corners with three equivalent Ag(5)Se4 tetrahedra, and corners with three equivalent Ag(6)Se4 tetrahedra. In the fourth Sn site, Sn(4) is bonded to one Se(1), one Se(12), one Se(3), and one Se(9) atom to form SnSe4 tetrahedra that share  a cornercorner with one Ag(1)Se4 tetrahedra,  a cornercorner with one Ag(2)Se4 tetrahedra,  a cornercorner with one Ag(5)Se4 tetrahedra,  a cornercorner with one Ag(6)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(3)Se4 tetrahedra, corners with three equivalent Ag(7)Se4 tetrahedra, and corners with three equivalent Ag(8)Se4 tetrahedra. There are twelve inequivalent Se sites. In the first Se site, Se(1) is bonded to one Ag(7), one Ag(8), one Sn(1), and one Sn(4) atom to form SeAg2Sn2 tetrahedra that share  a cornercorner with one Se(2)Ag2Sn2 tetrahedra,  a cornercorner with one Se(3)Ag2Sn2 tetrahedra,  a cornercorner with one Se(11)Ag3Sn tetrahedra,  a cornercorner with one Se(4)Ag3Sn tetrahedra,  a cornercorner with one Se(5)Ag3Sn tetrahedra,  a cornercorner with one Se(8)Ag3Sn tetrahedra, corners with three equivalent Se(12)Ag3Sn tetrahedra, and corners with three equivalent Se(9)Ag3Sn tetrahedra. In the second Se site, Se(2) is bonded to one Ag(1), one Ag(2), one Sn(1), and one Sn(2) atom to form SeAg2Sn2 tetrahedra that share  a cornercorner with one Se(1)Ag2Sn2 tetrahedra,  a cornercorner with one Se(6)Ag2Sn2 tetrahedra,  a cornercorner with one Se(10)Ag3Sn tetrahedra,  a cornercorner with one Se(12)Ag3Sn tetrahedra,  a cornercorner with one Se(7)Ag3Sn tetrahedra,  a cornercorner with one Se(9)Ag3Sn tetrahedra, corners with three equivalent Se(11)Ag3Sn tetrahedra, and corners with three equivalent Se(8)Ag3Sn tetrahedra. In the third Se site, Se(3) is bonded to one Ag(5), one Ag(6), one Sn(3), and one Sn(4) atom to form SeAg2Sn2 tetrahedra that share  a cornercorner with one Se(1)Ag2Sn2 tetrahedra,  a cornercorner with one Se(6)Ag2Sn2 tetrahedra,  a cornercorner with one Se(10)Ag3Sn tetrahedra,  a cornercorner with one Se(12)Ag3Sn tetrahedra,  a cornercorner with one Se(7)Ag3Sn tetrahedra,  a cornercorner with one Se(9)Ag3Sn tetrahedra, corners with three equivalent Se(4)Ag3Sn tetrahedra, and corners with three equivalent Se(5)Ag3Sn tetrahedra. In the fourth Se site, Se(4) is bonded to one Ag(5), one Ag(6), one Ag(7), and one Sn(3) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(1)Ag2Sn2 tetrahedra,  a cornercorner with one Se(6)Ag2Sn2 tetrahedra,  a cornercorner with one Se(10)Ag3Sn tetrahedra,  a cornercorner with one Se(12)Ag3Sn tetrahedra,  a cornercorner with one Se(7)Ag3Sn tetrahedra,  a cornercorner with one Se(9)Ag3Sn tetrahedra, corners with three equivalent Se(3)Ag2Sn2 tetrahedra, and corners with three equivalent Se(5)Ag3Sn tetrahedra. In the fifth Se site, Se(5) is bonded to one Ag(5), one Ag(6), one Ag(8), and one Sn(3) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(1)Ag2Sn2 tetrahedra,  a cornercorner with one Se(6)Ag2Sn2 tetrahedra,  a cornercorner with one Se(10)Ag3Sn tetrahedra,  a cornercorner with one Se(12)Ag3Sn tetrahedra,  a cornercorner with one Se(7)Ag3Sn tetrahedra,  a cornercorner with one Se(9)Ag3Sn tetrahedra, corners with three equivalent Se(3)Ag2Sn2 tetrahedra, and corners with three equivalent Se(4)Ag3Sn tetrahedra. In the sixth Se site, Se(6) is bonded to one Ag(3), one Ag(4), one Sn(2), and one Sn(3) atom to form SeAg2Sn2 tetrahedra that share  a cornercorner with one Se(2)Ag2Sn2 tetrahedra,  a cornercorner with one Se(3)Ag2Sn2 tetrahedra,  a cornercorner with one Se(11)Ag3Sn tetrahedra,  a cornercorner with one Se(4)Ag3Sn tetrahedra,  a cornercorner with one Se(5)Ag3Sn tetrahedra,  a cornercorner with one Se(8)Ag3Sn tetrahedra, corners with three equivalent Se(10)Ag3Sn tetrahedra, and corners with three equivalent Se(7)Ag3Sn tetrahedra. In the seventh Se site, Se(7) is bonded to one Ag(3), one Ag(4), one Ag(5), and one Sn(2) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(2)Ag2Sn2 tetrahedra,  a cornercorner with one Se(3)Ag2Sn2 tetrahedra,  a cornercorner with one Se(11)Ag3Sn tetrahedra,  a cornercorner with one Se(4)Ag3Sn tetrahedra,  a cornercorner with one Se(5)Ag3Sn tetrahedra,  a cornercorner with one Se(8)Ag3Sn tetrahedra, corners with three equivalent Se(6)Ag2Sn2 tetrahedra, and corners with three equivalent Se(10)Ag3Sn tetrahedra. In the eighth Se site, Se(8) is bonded to one Ag(1), one Ag(2), one Ag(3), and one Sn(1) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(1)Ag2Sn2 tetrahedra,  a cornercorner with one Se(6)Ag2Sn2 tetrahedra,  a cornercorner with one Se(10)Ag3Sn tetrahedra,  a cornercorner with one Se(12)Ag3Sn tetrahedra,  a cornercorner with one Se(7)Ag3Sn tetrahedra,  a cornercorner with one Se(9)Ag3Sn tetrahedra, corners with three equivalent Se(2)Ag2Sn2 tetrahedra, and corners with three equivalent Se(11)Ag3Sn tetrahedra. In the ninth Se site, Se(9) is bonded to one Ag(2), one Ag(7), one Ag(8), and one Sn(4) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(2)Ag2Sn2 tetrahedra,  a cornercorner with one Se(3)Ag2Sn2 tetrahedra,  a cornercorner with one Se(11)Ag3Sn tetrahedra,  a cornercorner with one Se(4)Ag3Sn tetrahedra,  a cornercorner with one Se(5)Ag3Sn tetrahedra,  a cornercorner with one Se(8)Ag3Sn tetrahedra, corners with three equivalent Se(1)Ag2Sn2 tetrahedra, and corners with three equivalent Se(12)Ag3Sn tetrahedra. In the tenth Se site, Se(10) is bonded to one Ag(3), one Ag(4), one Ag(6), and one Sn(2) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(2)Ag2Sn2 tetrahedra,  a cornercorner with one Se(3)Ag2Sn2 tetrahedra,  a cornercorner with one Se(11)Ag3Sn tetrahedra,  a cornercorner with one Se(4)Ag3Sn tetrahedra,  a cornercorner with one Se(5)Ag3Sn tetrahedra,  a cornercorner with one Se(8)Ag3Sn tetrahedra, corners with three equivalent Se(6)Ag2Sn2 tetrahedra, and corners with three equivalent Se(7)Ag3Sn tetrahedra. In the eleventh Se site, Se(11) is bonded to one Ag(1), one Ag(2), one Ag(4), and one Sn(1) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(1)Ag2Sn2 tetrahedra,  a cornercorner with one Se(6)Ag2Sn2 tetrahedra,  a cornercorner with one Se(10)Ag3Sn tetrahedra,  a cornercorner with one Se(12)Ag3Sn tetrahedra,  a cornercorner with one Se(7)Ag3Sn tetrahedra,  a cornercorner with one Se(9)Ag3Sn tetrahedra, corners with three equivalent Se(2)Ag2Sn2 tetrahedra, and corners with three equivalent Se(8)Ag3Sn tetrahedra. In the twelfth Se site, Se(12) is bonded to one Ag(1), one Ag(7), one Ag(8), and one Sn(4) atom to form SeAg3Sn tetrahedra that share  a cornercorner with one Se(2)Ag2Sn2 tetrahedra,  a cornercorner with one Se(3)Ag2Sn2 tetrahedra,  a cornercorner with one Se(11)Ag3Sn tetrahedra,  a cornercorner with one Se(4)Ag3Sn tetrahedra,  a cornercorner with one Se(5)Ag3Sn tetrahedra,  a cornercorner with one Se(8)Ag3Sn tetrahedra, corners with three equivalent Se(1)Ag2Sn2 tetrahedra, and corners with three equivalent Se(9)Ag3Sn tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ag2SnSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.403
_cell_length_b   7.403
_cell_length_c   28.120
_cell_angle_alpha   87.069
_cell_angle_beta   87.069
_cell_angle_gamma   119.496
_symmetry_Int_Tables_number   1
_cell_volume   1334.285
_cell_formula_units_Z   8
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
  Ag  Ag0  1  0.841  0.693  0.988  1.0
  Ag  Ag1  1  0.693  0.841  0.488  1.0
  Ag  Ag2  1  0.528  0.025  0.984  1.0
  Ag  Ag3  1  0.025  0.528  0.484  1.0
  Ag  Ag4  1  0.881  0.371  0.861  1.0
  Ag  Ag5  1  0.371  0.881  0.361  1.0
  Ag  Ag6  1  0.222  0.057  0.860  1.0
  Ag  Ag7  1  0.057  0.222  0.360  1.0
  Ag  Ag8  1  0.902  0.097  0.738  1.0
  Ag  Ag9  1  0.097  0.902  0.238  1.0
  Ag  Ag10  1  0.600  0.442  0.733  1.0
  Ag  Ag11  1  0.442  0.600  0.233  1.0
  Ag  Ag12  1  0.638  0.127  0.607  1.0
  Ag  Ag13  1  0.127  0.638  0.107  1.0
  Ag  Ag14  1  0.296  0.468  0.612  1.0
  Ag  Ag15  1  0.468  0.296  0.112  1.0
  Sn  Sn16  1  0.161  0.328  0.980  1.0
  Sn  Sn17  1  0.328  0.161  0.480  1.0
  Sn  Sn18  1  0.551  0.704  0.855  1.0
  Sn  Sn19  1  0.704  0.551  0.355  1.0
  Sn  Sn20  1  0.277  0.762  0.730  1.0
  Sn  Sn21  1  0.762  0.277  0.230  1.0
  Sn  Sn22  1  0.972  0.790  0.606  1.0
  Sn  Sn23  1  0.790  0.972  0.106  1.0
  Se  Se24  1  0.312  0.145  0.575  1.0
  Se  Se25  1  0.145  0.312  0.075  1.0
  Se  Se26  1  0.506  0.679  0.950  1.0
  Se  Se27  1  0.679  0.506  0.450  1.0
  Se  Se28  1  0.954  0.786  0.701  1.0
  Se  Se29  1  0.786  0.954  0.201  1.0
  Se  Se30  1  0.592  0.107  0.701  1.0
  Se  Se31  1  0.107  0.592  0.201  1.0
  Se  Se32  1  0.260  0.431  0.706  1.0
  Se  Se33  1  0.431  0.260  0.206  1.0
  Se  Se34  1  0.227  0.726  0.825  1.0
  Se  Se35  1  0.726  0.227  0.325  1.0
  Se  Se36  1  0.883  0.042  0.831  1.0
  Se  Se37  1  0.042  0.883  0.331  1.0
  Se  Se38  1  0.864  0.374  0.954  1.0
  Se  Se39  1  0.374  0.864  0.454  1.0
  Se  Se40  1  0.979  0.476  0.577  1.0
  Se  Se41  1  0.476  0.979  0.077  1.0
  Se  Se42  1  0.567  0.394  0.827  1.0
  Se  Se43  1  0.394  0.567  0.327  1.0
  Se  Se44  1  0.192  0.023  0.954  1.0
  Se  Se45  1  0.023  0.192  0.454  1.0
  Se  Se46  1  0.654  0.800  0.581  1.0
  Se  Se47  1  0.800  0.654  0.081  1.0
[/CIF]
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