The compound described by Na2Sr3As4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 3-coordinate geometry to one As(1), one As(2), and one As(3) atom. In the second Na site, Na(2) is bonded to one As(2), one As(3), and two equivalent As(1) atoms to form distorted corner-sharing NaAs4 tetrahedra. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one As(2), two equivalent As(1), two equivalent As(3), and two equivalent As(4) atoms. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to one As(1), one As(2), two equivalent As(3), and two equivalent As(4) atoms. In the third Sr site, Sr(3) is bonded in a 5-coordinate geometry to one As(3), two equivalent As(1), and two equivalent As(2) atoms. There are four inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to one Na(1), two equivalent Na(2), one Sr(2), two equivalent Sr(1), and two equivalent Sr(3) atoms. In the second As site, As(2) is bonded in a 7-coordinate geometry to one Na(1), one Na(2), one Sr(1), one Sr(2), two equivalent Sr(3), and one As(4) atom. In the third As site, As(3) is bonded in a 8-coordinate geometry to one Na(1), one Na(2), one Sr(3), two equivalent Sr(1), two equivalent Sr(2), and one As(4) atom. In the fourth As site, As(4) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), one As(2), and one As(3) atom. is represented by the CIF file [CIF]
data_Na2Sr3As4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.342
_cell_length_b   9.646
_cell_length_c   13.868
_cell_angle_alpha   56.938
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1047.205
_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
  Na  Na0  1  0.930  0.246  0.217  1.0
  Na  Na1  1  0.709  0.844  0.860  1.0
  Na  Na2  1  0.791  0.844  0.360  1.0
  Na  Na3  1  0.570  0.246  0.717  1.0
  Na  Na4  1  0.430  0.754  0.283  1.0
  Na  Na5  1  0.209  0.156  0.640  1.0
  Na  Na6  1  0.291  0.156  0.140  1.0
  Na  Na7  1  0.070  0.754  0.783  1.0
  Sr  Sr8  1  0.054  0.270  0.941  1.0
  Sr  Sr9  1  0.969  0.425  0.647  1.0
  Sr  Sr10  1  0.824  0.103  0.570  1.0
  Sr  Sr11  1  0.676  0.103  0.070  1.0
  Sr  Sr12  1  0.446  0.270  0.441  1.0
  Sr  Sr13  1  0.531  0.425  0.147  1.0
  Sr  Sr14  1  0.469  0.575  0.853  1.0
  Sr  Sr15  1  0.554  0.730  0.559  1.0
  Sr  Sr16  1  0.324  0.897  0.930  1.0
  Sr  Sr17  1  0.176  0.897  0.430  1.0
  Sr  Sr18  1  0.031  0.575  0.353  1.0
  Sr  Sr19  1  0.946  0.730  0.059  1.0
  As  As20  1  0.020  0.962  0.191  1.0
  As  As21  1  0.889  0.768  0.602  1.0
  As  As22  1  0.779  0.480  0.973  1.0
  As  As23  1  0.775  0.511  0.781  1.0
  As  As24  1  0.725  0.511  0.281  1.0
  As  As25  1  0.721  0.480  0.473  1.0
  As  As26  1  0.611  0.768  0.102  1.0
  As  As27  1  0.480  0.962  0.691  1.0
  As  As28  1  0.520  0.038  0.309  1.0
  As  As29  1  0.389  0.232  0.898  1.0
  As  As30  1  0.279  0.520  0.527  1.0
  As  As31  1  0.275  0.489  0.719  1.0
  As  As32  1  0.225  0.489  0.219  1.0
  As  As33  1  0.111  0.232  0.398  1.0
  As  As34  1  0.221  0.520  0.027  1.0
  As  As35  1  0.980  0.038  0.809  1.0
[/CIF]
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The compound described by Na2Sr3As4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 3-coordinate geometry to one As(1), one As(2), and one As(3) atom. In the second Na site, Na(2) is bonded to one As(2), one As(3), and two equivalent As(1) atoms to form distorted corner-sharing NaAs4 tetrahedra. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one As(2), two equivalent As(1), two equivalent As(3), and two equivalent As(4) atoms. In the second Sr site, Sr(2) is bonded in a 6-coordinate geometry to one As(1), one As(2), two equivalent As(3), and two equivalent As(4) atoms. In the third Sr site, Sr(3) is bonded in a 5-coordinate geometry to one As(3), two equivalent As(1), and two equivalent As(2) atoms. There are four inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to one Na(1), two equivalent Na(2), one Sr(2), two equivalent Sr(1), and two equivalent Sr(3) atoms. In the second As site, As(2) is bonded in a 7-coordinate geometry to one Na(1), one Na(2), one Sr(1), one Sr(2), two equivalent Sr(3), and one As(4) atom. In the third As site, As(3) is bonded in a 8-coordinate geometry to one Na(1), one Na(2), one Sr(3), two equivalent Sr(1), two equivalent Sr(2), and one As(4) atom. In the fourth As site, As(4) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), one As(2), and one As(3) atom. is represented by the CIF file [CIF]
data_Na2Sr3As4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.342
_cell_length_b   9.646
_cell_length_c   13.868
_cell_angle_alpha   56.938
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1047.205
_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
  Na  Na0  1  0.930  0.246  0.217  1.0
  Na  Na1  1  0.709  0.844  0.860  1.0
  Na  Na2  1  0.791  0.844  0.360  1.0
  Na  Na3  1  0.570  0.246  0.717  1.0
  Na  Na4  1  0.430  0.754  0.283  1.0
  Na  Na5  1  0.209  0.156  0.640  1.0
  Na  Na6  1  0.291  0.156  0.140  1.0
  Na  Na7  1  0.070  0.754  0.783  1.0
  Sr  Sr8  1  0.054  0.270  0.941  1.0
  Sr  Sr9  1  0.969  0.425  0.647  1.0
  Sr  Sr10  1  0.824  0.103  0.570  1.0
  Sr  Sr11  1  0.676  0.103  0.070  1.0
  Sr  Sr12  1  0.446  0.270  0.441  1.0
  Sr  Sr13  1  0.531  0.425  0.147  1.0
  Sr  Sr14  1  0.469  0.575  0.853  1.0
  Sr  Sr15  1  0.554  0.730  0.559  1.0
  Sr  Sr16  1  0.324  0.897  0.930  1.0
  Sr  Sr17  1  0.176  0.897  0.430  1.0
  Sr  Sr18  1  0.031  0.575  0.353  1.0
  Sr  Sr19  1  0.946  0.730  0.059  1.0
  As  As20  1  0.020  0.962  0.191  1.0
  As  As21  1  0.889  0.768  0.602  1.0
  As  As22  1  0.779  0.480  0.973  1.0
  As  As23  1  0.775  0.511  0.781  1.0
  As  As24  1  0.725  0.511  0.281  1.0
  As  As25  1  0.721  0.480  0.473  1.0
  As  As26  1  0.611  0.768  0.102  1.0
  As  As27  1  0.480  0.962  0.691  1.0
  As  As28  1  0.520  0.038  0.309  1.0
  As  As29  1  0.389  0.232  0.898  1.0
  As  As30  1  0.279  0.520  0.527  1.0
  As  As31  1  0.275  0.489  0.719  1.0
  As  As32  1  0.225  0.489  0.219  1.0
  As  As33  1  0.111  0.232  0.398  1.0
  As  As34  1  0.221  0.520  0.027  1.0
  As  As35  1  0.980  0.038  0.809  1.0
[/CIF]
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