The compound described by Na2Zn3SiAs4 crystallizes in the monoclinic Cm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one As(1), one As(3), two equivalent As(2), and two equivalent As(4) atoms to form distorted NaAs6 octahedra that share  a cornercorner with one Zn(1)As4 tetrahedra,  a cornercorner with one Zn(3)As4 tetrahedra, corners with five equivalent Si(1)As4 tetrahedra, edges with two equivalent Na(1)As6 octahedra, edges with four equivalent Na(2)As6 octahedra,  an edgeedge with one Si(1)As4 tetrahedra, edges with two equivalent Zn(1)As4 tetrahedra, and edges with two equivalent Zn(3)As4 tetrahedra. In the second Na site, Na(2) is bonded to one As(2), one As(4), two equivalent As(1), and two equivalent As(3) atoms to form distorted NaAs6 octahedra that share  a cornercorner with one Si(1)As4 tetrahedra, corners with five equivalent Zn(1)As4 tetrahedra, corners with five equivalent Zn(3)As4 tetrahedra, edges with two equivalent Na(2)As6 octahedra, edges with four equivalent Na(1)As6 octahedra,  an edgeedge with one Zn(1)As4 tetrahedra,  an edgeedge with one Zn(3)As4 tetrahedra, and edges with two equivalent Si(1)As4 tetrahedra. There are three inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one As(1), one As(4), and two equivalent As(3) atoms to form distorted ZnAs4 tetrahedra that share  a cornercorner with one Na(1)As6 octahedra, corners with five equivalent Na(2)As6 octahedra, corners with two equivalent Zn(1)As4 tetrahedra, corners with four equivalent Si(1)As4 tetrahedra,  an edgeedge with one Na(2)As6 octahedra, edges with two equivalent Na(1)As6 octahedra, and edges with two equivalent Zn(3)As4 tetrahedra. The corner-sharing octahedral tilt angles range from 18-53°. In the second Zn site, Zn(2) is bonded in a 4-coordinate geometry to one As(1), one As(4), and two equivalent As(2) atoms. In the third Zn site, Zn(3) is bonded to one As(2), one As(3), and two equivalent As(1) atoms to form distorted ZnAs4 tetrahedra that share  a cornercorner with one Na(1)As6 octahedra, corners with five equivalent Na(2)As6 octahedra, corners with two equivalent Zn(3)As4 tetrahedra,  an edgeedge with one Na(2)As6 octahedra, edges with two equivalent Na(1)As6 octahedra,  an edgeedge with one Si(1)As4 tetrahedra, and edges with two equivalent Zn(1)As4 tetrahedra. The corner-sharing octahedral tilt angles range from 18-53°. Si(1) is bonded to one As(2), one As(3), and two equivalent As(4) atoms to form SiAs4 tetrahedra that share  a cornercorner with one Na(2)As6 octahedra, corners with five equivalent Na(1)As6 octahedra, corners with two equivalent Si(1)As4 tetrahedra, corners with four equivalent Zn(1)As4 tetrahedra,  an edgeedge with one Na(1)As6 octahedra, edges with two equivalent Na(2)As6 octahedra, and  an edgeedge with one Zn(3)As4 tetrahedra. The corner-sharing octahedral tilt angles range from 18-48°. There are four inequivalent As sites. In the first As site, As(1) is bonded to one Na(1), two equivalent Na(2), one Zn(1), one Zn(2), and two equivalent Zn(3) atoms to form distorted edge-sharing AsNa3Zn4 pentagonal bipyramids. In the second As site, As(2) is bonded in a 7-coordinate geometry to one Na(2), two equivalent Na(1), one Zn(3), two equivalent Zn(2), and one Si(1) atom. In the third As site, As(3) is bonded in a 7-coordinate geometry to one Na(1), two equivalent Na(2), one Zn(3), two equivalent Zn(1), and one Si(1) atom. In the fourth As site, As(4) is bonded in a 7-coordinate geometry to one Na(2), two equivalent Na(1), one Zn(1), one Zn(2), and two equivalent Si(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2Zn3SiAs4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.528
_cell_length_b   8.528
_cell_length_c   7.129
_cell_angle_alpha   65.385
_cell_angle_beta   65.385
_cell_angle_gamma   27.704
_symmetry_Int_Tables_number   1
_cell_volume   217.719
_cell_formula_units_Z   1
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
  Na  Na0  1  0.493  0.493  0.505  1.0
  Na  Na1  1  0.995  0.995  0.006  1.0
  Zn  Zn2  1  0.195  0.195  0.482  1.0
  Zn  Zn3  1  0.322  0.322  0.028  1.0
  Zn  Zn4  1  0.816  0.816  0.503  1.0
  Si  Si5  1  0.689  0.689  0.964  1.0
  As  As6  1  0.371  0.371  0.300  1.0
  As  As7  1  0.850  0.850  0.812  1.0
  As  As8  1  0.629  0.629  0.710  1.0
  As  As9  1  0.134  0.134  0.191  1.0
[/CIF]
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The compound described by Na2Zn3SiAs4 crystallizes in the monoclinic Cm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one As(1), one As(3), two equivalent As(2), and two equivalent As(4) atoms to form distorted NaAs6 octahedra that share  a cornercorner with one Zn(1)As4 tetrahedra,  a cornercorner with one Zn(3)As4 tetrahedra, corners with five equivalent Si(1)As4 tetrahedra, edges with two equivalent Na(1)As6 octahedra, edges with four equivalent Na(2)As6 octahedra,  an edgeedge with one Si(1)As4 tetrahedra, edges with two equivalent Zn(1)As4 tetrahedra, and edges with two equivalent Zn(3)As4 tetrahedra. In the second Na site, Na(2) is bonded to one As(2), one As(4), two equivalent As(1), and two equivalent As(3) atoms to form distorted NaAs6 octahedra that share  a cornercorner with one Si(1)As4 tetrahedra, corners with five equivalent Zn(1)As4 tetrahedra, corners with five equivalent Zn(3)As4 tetrahedra, edges with two equivalent Na(2)As6 octahedra, edges with four equivalent Na(1)As6 octahedra,  an edgeedge with one Zn(1)As4 tetrahedra,  an edgeedge with one Zn(3)As4 tetrahedra, and edges with two equivalent Si(1)As4 tetrahedra. There are three inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one As(1), one As(4), and two equivalent As(3) atoms to form distorted ZnAs4 tetrahedra that share  a cornercorner with one Na(1)As6 octahedra, corners with five equivalent Na(2)As6 octahedra, corners with two equivalent Zn(1)As4 tetrahedra, corners with four equivalent Si(1)As4 tetrahedra,  an edgeedge with one Na(2)As6 octahedra, edges with two equivalent Na(1)As6 octahedra, and edges with two equivalent Zn(3)As4 tetrahedra. The corner-sharing octahedral tilt angles range from 18-53°. In the second Zn site, Zn(2) is bonded in a 4-coordinate geometry to one As(1), one As(4), and two equivalent As(2) atoms. In the third Zn site, Zn(3) is bonded to one As(2), one As(3), and two equivalent As(1) atoms to form distorted ZnAs4 tetrahedra that share  a cornercorner with one Na(1)As6 octahedra, corners with five equivalent Na(2)As6 octahedra, corners with two equivalent Zn(3)As4 tetrahedra,  an edgeedge with one Na(2)As6 octahedra, edges with two equivalent Na(1)As6 octahedra,  an edgeedge with one Si(1)As4 tetrahedra, and edges with two equivalent Zn(1)As4 tetrahedra. The corner-sharing octahedral tilt angles range from 18-53°. Si(1) is bonded to one As(2), one As(3), and two equivalent As(4) atoms to form SiAs4 tetrahedra that share  a cornercorner with one Na(2)As6 octahedra, corners with five equivalent Na(1)As6 octahedra, corners with two equivalent Si(1)As4 tetrahedra, corners with four equivalent Zn(1)As4 tetrahedra,  an edgeedge with one Na(1)As6 octahedra, edges with two equivalent Na(2)As6 octahedra, and  an edgeedge with one Zn(3)As4 tetrahedra. The corner-sharing octahedral tilt angles range from 18-48°. There are four inequivalent As sites. In the first As site, As(1) is bonded to one Na(1), two equivalent Na(2), one Zn(1), one Zn(2), and two equivalent Zn(3) atoms to form distorted edge-sharing AsNa3Zn4 pentagonal bipyramids. In the second As site, As(2) is bonded in a 7-coordinate geometry to one Na(2), two equivalent Na(1), one Zn(3), two equivalent Zn(2), and one Si(1) atom. In the third As site, As(3) is bonded in a 7-coordinate geometry to one Na(1), two equivalent Na(2), one Zn(3), two equivalent Zn(1), and one Si(1) atom. In the fourth As site, As(4) is bonded in a 7-coordinate geometry to one Na(2), two equivalent Na(1), one Zn(1), one Zn(2), and two equivalent Si(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2Zn3SiAs4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.528
_cell_length_b   8.528
_cell_length_c   7.129
_cell_angle_alpha   65.385
_cell_angle_beta   65.385
_cell_angle_gamma   27.704
_symmetry_Int_Tables_number   1
_cell_volume   217.719
_cell_formula_units_Z   1
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
  Na  Na0  1  0.493  0.493  0.505  1.0
  Na  Na1  1  0.995  0.995  0.006  1.0
  Zn  Zn2  1  0.195  0.195  0.482  1.0
  Zn  Zn3  1  0.322  0.322  0.028  1.0
  Zn  Zn4  1  0.816  0.816  0.503  1.0
  Si  Si5  1  0.689  0.689  0.964  1.0
  As  As6  1  0.371  0.371  0.300  1.0
  As  As7  1  0.850  0.850  0.812  1.0
  As  As8  1  0.629  0.629  0.710  1.0
  As  As9  1  0.134  0.134  0.191  1.0
[/CIF]
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