The compound described by Ba7Ga4As9 crystallizes in the orthorhombic Pmmn space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one Ga(1), two equivalent As(2), and four equivalent As(1) atoms. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to one Ga(1), one As(3), one As(4), one As(5), two equivalent As(1), and two equivalent As(2) atoms. In the third Ba site, Ba(3) is bonded in a 1-coordinate geometry to one As(5) and four equivalent As(1) atoms. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one Ba(1), two equivalent Ba(2), one As(2), one As(5), and two equivalent As(1) atoms to form distorted GaBa3As4 tetrahedra that share  a cornercorner with one Ga(1)Ba3As4 tetrahedra and corners with two equivalent Ga(2)As4 tetrahedra. In the second Ga site, Ga(2) is bonded to one As(3), one As(4), and two equivalent As(1) atoms to form distorted GaAs4 tetrahedra that share corners with two equivalent Ga(1)Ba3As4 tetrahedra and  an edgeedge with one Ga(2)As4 tetrahedra. There are five inequivalent As sites. In the first As site, As(3) is bonded in a 6-coordinate geometry to four equivalent Ba(2) and two equivalent Ga(2) atoms. In the second As site, As(4) is bonded in a 6-coordinate geometry to four equivalent Ba(2) and two equivalent Ga(2) atoms. In the third As site, As(5) is bonded in a distorted trigonal planar geometry to one Ba(3), four equivalent Ba(2), and two equivalent Ga(1) atoms. In the fourth As site, As(1) is bonded in a 7-coordinate geometry to one Ba(3), two equivalent Ba(1), two equivalent Ba(2), one Ga(1), and one Ga(2) atom. In the fifth As site, As(2) is bonded in a 7-coordinate geometry to two equivalent Ba(1), four equivalent Ba(2), and one Ga(1) atom. is represented by the CIF file [CIF]
data_Ba7Ga4As9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.865
_cell_length_b   10.245
_cell_length_c   17.189
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1209.085
_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
  Ba  Ba0  1  0.451  0.500  0.784  1.0
  Ba  Ba1  1  0.451  0.500  0.216  1.0
  Ba  Ba2  1  0.549  0.000  0.716  1.0
  Ba  Ba3  1  0.549  0.000  0.284  1.0
  Ba  Ba4  1  0.946  0.277  0.875  1.0
  Ba  Ba5  1  0.946  0.723  0.875  1.0
  Ba  Ba6  1  0.946  0.277  0.125  1.0
  Ba  Ba7  1  0.946  0.723  0.125  1.0
  Ba  Ba8  1  0.054  0.223  0.625  1.0
  Ba  Ba9  1  0.054  0.777  0.625  1.0
  Ba  Ba10  1  0.054  0.223  0.375  1.0
  Ba  Ba11  1  0.054  0.777  0.375  1.0
  Ba  Ba12  1  0.405  0.500  0.500  1.0
  Ba  Ba13  1  0.595  0.000  0.000  1.0
  Ga  Ga14  1  0.766  0.500  0.376  1.0
  Ga  Ga15  1  0.766  0.500  0.624  1.0
  Ga  Ga16  1  0.234  0.000  0.124  1.0
  Ga  Ga17  1  0.234  0.000  0.876  1.0
  Ga  Ga18  1  0.570  0.823  0.500  1.0
  Ga  Ga19  1  0.570  0.177  0.500  1.0
  Ga  Ga20  1  0.430  0.677  0.000  1.0
  Ga  Ga21  1  0.430  0.323  0.000  1.0
  As  As22  1  0.560  0.291  0.372  1.0
  As  As23  1  0.560  0.709  0.372  1.0
  As  As24  1  0.560  0.291  0.628  1.0
  As  As25  1  0.560  0.709  0.628  1.0
  As  As26  1  0.440  0.209  0.128  1.0
  As  As27  1  0.440  0.791  0.128  1.0
  As  As28  1  0.440  0.209  0.872  1.0
  As  As29  1  0.440  0.791  0.872  1.0
  As  As30  1  0.978  0.500  0.263  1.0
  As  As31  1  0.978  0.500  0.737  1.0
  As  As32  1  0.022  0.000  0.237  1.0
  As  As33  1  0.022  0.000  0.763  1.0
  As  As34  1  0.693  0.500  0.000  1.0
  As  As35  1  0.307  0.000  0.500  1.0
  As  As36  1  0.168  0.500  0.000  1.0
  As  As37  1  0.832  0.000  0.500  1.0
  As  As38  1  0.952  0.500  0.500  1.0
  As  As39  1  0.048  0.000  0.000  1.0
[/CIF]
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The compound described by Ba7Ga4As9 crystallizes in the orthorhombic Pmmn space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one Ga(1), two equivalent As(2), and four equivalent As(1) atoms. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to one Ga(1), one As(3), one As(4), one As(5), two equivalent As(1), and two equivalent As(2) atoms. In the third Ba site, Ba(3) is bonded in a 1-coordinate geometry to one As(5) and four equivalent As(1) atoms. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one Ba(1), two equivalent Ba(2), one As(2), one As(5), and two equivalent As(1) atoms to form distorted GaBa3As4 tetrahedra that share  a cornercorner with one Ga(1)Ba3As4 tetrahedra and corners with two equivalent Ga(2)As4 tetrahedra. In the second Ga site, Ga(2) is bonded to one As(3), one As(4), and two equivalent As(1) atoms to form distorted GaAs4 tetrahedra that share corners with two equivalent Ga(1)Ba3As4 tetrahedra and  an edgeedge with one Ga(2)As4 tetrahedra. There are five inequivalent As sites. In the first As site, As(3) is bonded in a 6-coordinate geometry to four equivalent Ba(2) and two equivalent Ga(2) atoms. In the second As site, As(4) is bonded in a 6-coordinate geometry to four equivalent Ba(2) and two equivalent Ga(2) atoms. In the third As site, As(5) is bonded in a distorted trigonal planar geometry to one Ba(3), four equivalent Ba(2), and two equivalent Ga(1) atoms. In the fourth As site, As(1) is bonded in a 7-coordinate geometry to one Ba(3), two equivalent Ba(1), two equivalent Ba(2), one Ga(1), and one Ga(2) atom. In the fifth As site, As(2) is bonded in a 7-coordinate geometry to two equivalent Ba(1), four equivalent Ba(2), and one Ga(1) atom. is represented by the CIF file [CIF]
data_Ba7Ga4As9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.865
_cell_length_b   10.245
_cell_length_c   17.189
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1209.085
_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
  Ba  Ba0  1  0.451  0.500  0.784  1.0
  Ba  Ba1  1  0.451  0.500  0.216  1.0
  Ba  Ba2  1  0.549  0.000  0.716  1.0
  Ba  Ba3  1  0.549  0.000  0.284  1.0
  Ba  Ba4  1  0.946  0.277  0.875  1.0
  Ba  Ba5  1  0.946  0.723  0.875  1.0
  Ba  Ba6  1  0.946  0.277  0.125  1.0
  Ba  Ba7  1  0.946  0.723  0.125  1.0
  Ba  Ba8  1  0.054  0.223  0.625  1.0
  Ba  Ba9  1  0.054  0.777  0.625  1.0
  Ba  Ba10  1  0.054  0.223  0.375  1.0
  Ba  Ba11  1  0.054  0.777  0.375  1.0
  Ba  Ba12  1  0.405  0.500  0.500  1.0
  Ba  Ba13  1  0.595  0.000  0.000  1.0
  Ga  Ga14  1  0.766  0.500  0.376  1.0
  Ga  Ga15  1  0.766  0.500  0.624  1.0
  Ga  Ga16  1  0.234  0.000  0.124  1.0
  Ga  Ga17  1  0.234  0.000  0.876  1.0
  Ga  Ga18  1  0.570  0.823  0.500  1.0
  Ga  Ga19  1  0.570  0.177  0.500  1.0
  Ga  Ga20  1  0.430  0.677  0.000  1.0
  Ga  Ga21  1  0.430  0.323  0.000  1.0
  As  As22  1  0.560  0.291  0.372  1.0
  As  As23  1  0.560  0.709  0.372  1.0
  As  As24  1  0.560  0.291  0.628  1.0
  As  As25  1  0.560  0.709  0.628  1.0
  As  As26  1  0.440  0.209  0.128  1.0
  As  As27  1  0.440  0.791  0.128  1.0
  As  As28  1  0.440  0.209  0.872  1.0
  As  As29  1  0.440  0.791  0.872  1.0
  As  As30  1  0.978  0.500  0.263  1.0
  As  As31  1  0.978  0.500  0.737  1.0
  As  As32  1  0.022  0.000  0.237  1.0
  As  As33  1  0.022  0.000  0.763  1.0
  As  As34  1  0.693  0.500  0.000  1.0
  As  As35  1  0.307  0.000  0.500  1.0
  As  As36  1  0.168  0.500  0.000  1.0
  As  As37  1  0.832  0.000  0.500  1.0
  As  As38  1  0.952  0.500  0.500  1.0
  As  As39  1  0.048  0.000  0.000  1.0
[/CIF]
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