The material described by ZnSn2(PO4)2 crystallizes in the triclinic P-1 space group. Zn(1,2) is bonded to one O(1), one O(11), one O(2), and one O(8) atom to form ZnO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. There are three inequivalent Sn sites. In the first Sn site, Sn(1,2) is bonded in a 3-coordinate geometry to one O(2), one O(5), and one O(7) atom. In the second Sn site, Sn(3,5) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(5) atoms. In the third Sn site, Sn(4) is bonded in a distorted rectangular see-saw-like geometry to one O(10), one O(14), one O(16), and one O(6) atom. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(10), one O(13), and one O(5) atom to form PO4 tetrahedra that share corners with two equivalent Zn(1,2)O4 tetrahedra. In the second P site, P(2) is bonded to one O(12), one O(4), one O(6), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Zn(1,2)O4 tetrahedra. In the third P site, P(3) is bonded to one O(16), one O(2), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Zn(1,2)O4 tetrahedra. In the fourth P site, P(4) is bonded to one O(11), one O(14), one O(15), and one O(3) atom to form PO4 tetrahedra that share corners with two equivalent Zn(1,2)O4 tetrahedra. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Zn(1,2); one Sn(3,5); and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Zn(1,2); one Sn(1,2); and one P(3) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Zn(1,2); one Sn(3,5); and one P(4) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Sn(1,2) and one P(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Sn(1,2); one Sn(3,5); and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Sn(4) and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Sn(1,2) and one P(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Zn(1,2) and one P(3) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Zn(1,2); one Sn(1,2); and one P(2) atom. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one Sn(4) and one P(1) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Zn(1,2) and one P(4) atom. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to one Zn(1,2) and one P(2) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one Zn(1,2) and one P(1) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 120 degrees geometry to one Sn(4) and one P(4) atom. In the fifteenth O site, O(15) is bonded in a 3-coordinate geometry to one Sn(1,2); one Sn(3,5); and one P(4) atom. In the sixteenth O site, O(16) is bonded in a distorted bent 120 degrees geometry to one Sn(4) and one P(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_ZnSn2(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.627
_cell_length_b   9.627
_cell_length_c   18.689
_cell_angle_alpha   61.959
_cell_angle_beta   61.959
_cell_angle_gamma   31.541
_symmetry_Int_Tables_number   1
_cell_volume   790.596
_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
  Zn  Zn0  1  0.070  0.621  0.660  1.0
  Zn  Zn1  1  0.379  0.930  0.840  1.0
  Zn  Zn2  1  0.621  0.070  0.160  1.0
  Zn  Zn3  1  0.930  0.379  0.340  1.0
  Sn  Sn4  1  0.376  0.814  0.511  1.0
  Sn  Sn5  1  0.186  0.624  0.989  1.0
  Sn  Sn6  1  0.624  0.186  0.489  1.0
  Sn  Sn7  1  0.000  0.500  0.500  1.0
  Sn  Sn8  1  0.814  0.376  0.011  1.0
  Sn  Sn9  1  0.660  0.346  0.249  1.0
  Sn  Sn10  1  0.340  0.654  0.751  1.0
  Sn  Sn11  1  0.500  0.000  0.000  1.0
  P  P12  1  0.535  0.914  0.639  1.0
  P  P13  1  0.760  0.310  0.877  1.0
  P  P14  1  0.465  0.086  0.361  1.0
  P  P15  1  0.310  0.760  0.377  1.0
  P  P16  1  0.914  0.535  0.139  1.0
  P  P17  1  0.086  0.465  0.861  1.0
  P  P18  1  0.240  0.690  0.123  1.0
  P  P19  1  0.690  0.240  0.623  1.0
  O  O20  1  0.163  0.271  0.390  1.0
  O  O21  1  0.459  0.358  0.604  1.0
  O  O22  1  0.271  0.163  0.890  1.0
  O  O23  1  0.624  0.264  0.947  1.0
  O  O24  1  0.623  0.835  0.431  1.0
  O  O25  1  0.697  0.397  0.792  1.0
  O  O26  1  0.736  0.376  0.553  1.0
  O  O27  1  0.045  0.067  0.379  1.0
  O  O28  1  0.376  0.736  0.053  1.0
  O  O29  1  0.642  0.541  0.896  1.0
  O  O30  1  0.461  0.248  0.369  1.0
  O  O31  1  0.001  0.421  0.221  1.0
  O  O32  1  0.541  0.642  0.396  1.0
  O  O33  1  0.067  0.045  0.879  1.0
  O  O34  1  0.837  0.729  0.610  1.0
  O  O35  1  0.539  0.752  0.631  1.0
  O  O36  1  0.421  0.001  0.721  1.0
  O  O37  1  0.264  0.624  0.447  1.0
  O  O38  1  0.248  0.461  0.869  1.0
  O  O39  1  0.999  0.579  0.779  1.0
  O  O40  1  0.933  0.955  0.121  1.0
  O  O41  1  0.835  0.623  0.931  1.0
  O  O42  1  0.955  0.933  0.621  1.0
  O  O43  1  0.397  0.697  0.292  1.0
  O  O44  1  0.358  0.459  0.104  1.0
  O  O45  1  0.729  0.837  0.110  1.0
  O  O46  1  0.579  0.999  0.279  1.0
  O  O47  1  0.165  0.377  0.069  1.0
  O  O48  1  0.377  0.165  0.569  1.0
  O  O49  1  0.603  0.303  0.708  1.0
  O  O50  1  0.303  0.603  0.208  1.0
  O  O51  1  0.752  0.539  0.131  1.0
[/CIF]
.
The material described by ZnSn2(PO4)2 crystallizes in the triclinic P-1 space group. Zn(1,2) is bonded to one O(1), one O(11), one O(2), and one O(8) atom to form ZnO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. There are three inequivalent Sn sites. In the first Sn site, Sn(1,2) is bonded in a 3-coordinate geometry to one O(2), one O(5), and one O(7) atom. In the second Sn site, Sn(3,5) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(5) atoms. In the third Sn site, Sn(4) is bonded in a distorted rectangular see-saw-like geometry to one O(10), one O(14), one O(16), and one O(6) atom. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(10), one O(13), and one O(5) atom to form PO4 tetrahedra that share corners with two equivalent Zn(1,2)O4 tetrahedra. In the second P site, P(2) is bonded to one O(12), one O(4), one O(6), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Zn(1,2)O4 tetrahedra. In the third P site, P(3) is bonded to one O(16), one O(2), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Zn(1,2)O4 tetrahedra. In the fourth P site, P(4) is bonded to one O(11), one O(14), one O(15), and one O(3) atom to form PO4 tetrahedra that share corners with two equivalent Zn(1,2)O4 tetrahedra. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Zn(1,2); one Sn(3,5); and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Zn(1,2); one Sn(1,2); and one P(3) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Zn(1,2); one Sn(3,5); and one P(4) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Sn(1,2) and one P(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Sn(1,2); one Sn(3,5); and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Sn(4) and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Sn(1,2) and one P(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Zn(1,2) and one P(3) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Zn(1,2); one Sn(1,2); and one P(2) atom. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one Sn(4) and one P(1) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Zn(1,2) and one P(4) atom. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to one Zn(1,2) and one P(2) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one Zn(1,2) and one P(1) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 120 degrees geometry to one Sn(4) and one P(4) atom. In the fifteenth O site, O(15) is bonded in a 3-coordinate geometry to one Sn(1,2); one Sn(3,5); and one P(4) atom. In the sixteenth O site, O(16) is bonded in a distorted bent 120 degrees geometry to one Sn(4) and one P(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_ZnSn2(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.627
_cell_length_b   9.627
_cell_length_c   18.689
_cell_angle_alpha   61.959
_cell_angle_beta   61.959
_cell_angle_gamma   31.541
_symmetry_Int_Tables_number   1
_cell_volume   790.596
_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
  Zn  Zn0  1  0.070  0.621  0.660  1.0
  Zn  Zn1  1  0.379  0.930  0.840  1.0
  Zn  Zn2  1  0.621  0.070  0.160  1.0
  Zn  Zn3  1  0.930  0.379  0.340  1.0
  Sn  Sn4  1  0.376  0.814  0.511  1.0
  Sn  Sn5  1  0.186  0.624  0.989  1.0
  Sn  Sn6  1  0.624  0.186  0.489  1.0
  Sn  Sn7  1  0.000  0.500  0.500  1.0
  Sn  Sn8  1  0.814  0.376  0.011  1.0
  Sn  Sn9  1  0.660  0.346  0.249  1.0
  Sn  Sn10  1  0.340  0.654  0.751  1.0
  Sn  Sn11  1  0.500  0.000  0.000  1.0
  P  P12  1  0.535  0.914  0.639  1.0
  P  P13  1  0.760  0.310  0.877  1.0
  P  P14  1  0.465  0.086  0.361  1.0
  P  P15  1  0.310  0.760  0.377  1.0
  P  P16  1  0.914  0.535  0.139  1.0
  P  P17  1  0.086  0.465  0.861  1.0
  P  P18  1  0.240  0.690  0.123  1.0
  P  P19  1  0.690  0.240  0.623  1.0
  O  O20  1  0.163  0.271  0.390  1.0
  O  O21  1  0.459  0.358  0.604  1.0
  O  O22  1  0.271  0.163  0.890  1.0
  O  O23  1  0.624  0.264  0.947  1.0
  O  O24  1  0.623  0.835  0.431  1.0
  O  O25  1  0.697  0.397  0.792  1.0
  O  O26  1  0.736  0.376  0.553  1.0
  O  O27  1  0.045  0.067  0.379  1.0
  O  O28  1  0.376  0.736  0.053  1.0
  O  O29  1  0.642  0.541  0.896  1.0
  O  O30  1  0.461  0.248  0.369  1.0
  O  O31  1  0.001  0.421  0.221  1.0
  O  O32  1  0.541  0.642  0.396  1.0
  O  O33  1  0.067  0.045  0.879  1.0
  O  O34  1  0.837  0.729  0.610  1.0
  O  O35  1  0.539  0.752  0.631  1.0
  O  O36  1  0.421  0.001  0.721  1.0
  O  O37  1  0.264  0.624  0.447  1.0
  O  O38  1  0.248  0.461  0.869  1.0
  O  O39  1  0.999  0.579  0.779  1.0
  O  O40  1  0.933  0.955  0.121  1.0
  O  O41  1  0.835  0.623  0.931  1.0
  O  O42  1  0.955  0.933  0.621  1.0
  O  O43  1  0.397  0.697  0.292  1.0
  O  O44  1  0.358  0.459  0.104  1.0
  O  O45  1  0.729  0.837  0.110  1.0
  O  O46  1  0.579  0.999  0.279  1.0
  O  O47  1  0.165  0.377  0.069  1.0
  O  O48  1  0.377  0.165  0.569  1.0
  O  O49  1  0.603  0.303  0.708  1.0
  O  O50  1  0.303  0.603  0.208  1.0
  O  O51  1  0.752  0.539  0.131  1.0
[/CIF]
.