The structure described by Sc2Nb3Si4 crystallizes in the orthorhombic Pnma space group. Sc(1) is bonded in a 7-coordinate geometry to one Si(2), two equivalent Si(3), and four equivalent Si(1) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 6-coordinate geometry to one Si(3), two equivalent Si(2), and three equivalent Si(1) atoms. In the second Nb site, Nb(2) is bonded to two equivalent Si(1), two equivalent Si(2), and two equivalent Si(3) atoms to form distorted corner-sharing NbSi6 octahedra. The corner-sharing octahedral tilt angles range from 50-56°. There are three inequivalent Si sites. In the first Si site, Si(3) is bonded in a 9-coordinate geometry to four equivalent Sc(1), two equivalent Nb(1), two equivalent Nb(2), and one Si(2) atom. In the second Si site, Si(1) is bonded in a 9-coordinate geometry to four equivalent Sc(1), one Nb(2), three equivalent Nb(1), and one Si(1) atom. In the third Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Sc(1), two equivalent Nb(2), four equivalent Nb(1), and one Si(3) atom. is represented by the CIF file [CIF]
data_Sc2Nb3Si4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.710
_cell_length_b   6.909
_cell_length_c   13.137
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   608.995
_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
  Sc  Sc0  1  0.503  0.674  0.596  1.0
  Sc  Sc1  1  0.003  0.826  0.904  1.0
  Sc  Sc2  1  0.497  0.326  0.096  1.0
  Sc  Sc3  1  0.997  0.174  0.404  1.0
  Sc  Sc4  1  0.497  0.326  0.404  1.0
  Sc  Sc5  1  0.997  0.174  0.096  1.0
  Sc  Sc6  1  0.503  0.674  0.904  1.0
  Sc  Sc7  1  0.003  0.826  0.596  1.0
  Nb  Nb8  1  0.663  0.177  0.625  1.0
  Nb  Nb9  1  0.163  0.323  0.875  1.0
  Nb  Nb10  1  0.337  0.823  0.125  1.0
  Nb  Nb11  1  0.837  0.677  0.375  1.0
  Nb  Nb12  1  0.337  0.823  0.375  1.0
  Nb  Nb13  1  0.837  0.677  0.125  1.0
  Nb  Nb14  1  0.663  0.177  0.875  1.0
  Nb  Nb15  1  0.163  0.323  0.625  1.0
  Nb  Nb16  1  0.838  0.495  0.750  1.0
  Nb  Nb17  1  0.338  0.005  0.750  1.0
  Nb  Nb18  1  0.162  0.505  0.250  1.0
  Nb  Nb19  1  0.662  0.995  0.250  1.0
  Si  Si20  1  0.667  0.968  0.461  1.0
  Si  Si21  1  0.167  0.532  0.039  1.0
  Si  Si22  1  0.333  0.032  0.961  1.0
  Si  Si23  1  0.833  0.468  0.539  1.0
  Si  Si24  1  0.333  0.032  0.539  1.0
  Si  Si25  1  0.833  0.468  0.961  1.0
  Si  Si26  1  0.667  0.968  0.039  1.0
  Si  Si27  1  0.167  0.532  0.461  1.0
  Si  Si28  1  0.460  0.387  0.750  1.0
  Si  Si29  1  0.960  0.113  0.750  1.0
  Si  Si30  1  0.540  0.613  0.250  1.0
  Si  Si31  1  0.040  0.887  0.250  1.0
  Si  Si32  1  0.706  0.865  0.750  1.0
  Si  Si33  1  0.206  0.635  0.750  1.0
  Si  Si34  1  0.294  0.135  0.250  1.0
  Si  Si35  1  0.794  0.365  0.250  1.0
[/CIF]
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The structure described by Sc2Nb3Si4 crystallizes in the orthorhombic Pnma space group. Sc(1) is bonded in a 7-coordinate geometry to one Si(2), two equivalent Si(3), and four equivalent Si(1) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 6-coordinate geometry to one Si(3), two equivalent Si(2), and three equivalent Si(1) atoms. In the second Nb site, Nb(2) is bonded to two equivalent Si(1), two equivalent Si(2), and two equivalent Si(3) atoms to form distorted corner-sharing NbSi6 octahedra. The corner-sharing octahedral tilt angles range from 50-56°. There are three inequivalent Si sites. In the first Si site, Si(3) is bonded in a 9-coordinate geometry to four equivalent Sc(1), two equivalent Nb(1), two equivalent Nb(2), and one Si(2) atom. In the second Si site, Si(1) is bonded in a 9-coordinate geometry to four equivalent Sc(1), one Nb(2), three equivalent Nb(1), and one Si(1) atom. In the third Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Sc(1), two equivalent Nb(2), four equivalent Nb(1), and one Si(3) atom. is represented by the CIF file [CIF]
data_Sc2Nb3Si4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.710
_cell_length_b   6.909
_cell_length_c   13.137
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   608.995
_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
  Sc  Sc0  1  0.503  0.674  0.596  1.0
  Sc  Sc1  1  0.003  0.826  0.904  1.0
  Sc  Sc2  1  0.497  0.326  0.096  1.0
  Sc  Sc3  1  0.997  0.174  0.404  1.0
  Sc  Sc4  1  0.497  0.326  0.404  1.0
  Sc  Sc5  1  0.997  0.174  0.096  1.0
  Sc  Sc6  1  0.503  0.674  0.904  1.0
  Sc  Sc7  1  0.003  0.826  0.596  1.0
  Nb  Nb8  1  0.663  0.177  0.625  1.0
  Nb  Nb9  1  0.163  0.323  0.875  1.0
  Nb  Nb10  1  0.337  0.823  0.125  1.0
  Nb  Nb11  1  0.837  0.677  0.375  1.0
  Nb  Nb12  1  0.337  0.823  0.375  1.0
  Nb  Nb13  1  0.837  0.677  0.125  1.0
  Nb  Nb14  1  0.663  0.177  0.875  1.0
  Nb  Nb15  1  0.163  0.323  0.625  1.0
  Nb  Nb16  1  0.838  0.495  0.750  1.0
  Nb  Nb17  1  0.338  0.005  0.750  1.0
  Nb  Nb18  1  0.162  0.505  0.250  1.0
  Nb  Nb19  1  0.662  0.995  0.250  1.0
  Si  Si20  1  0.667  0.968  0.461  1.0
  Si  Si21  1  0.167  0.532  0.039  1.0
  Si  Si22  1  0.333  0.032  0.961  1.0
  Si  Si23  1  0.833  0.468  0.539  1.0
  Si  Si24  1  0.333  0.032  0.539  1.0
  Si  Si25  1  0.833  0.468  0.961  1.0
  Si  Si26  1  0.667  0.968  0.039  1.0
  Si  Si27  1  0.167  0.532  0.461  1.0
  Si  Si28  1  0.460  0.387  0.750  1.0
  Si  Si29  1  0.960  0.113  0.750  1.0
  Si  Si30  1  0.540  0.613  0.250  1.0
  Si  Si31  1  0.040  0.887  0.250  1.0
  Si  Si32  1  0.706  0.865  0.750  1.0
  Si  Si33  1  0.206  0.635  0.750  1.0
  Si  Si34  1  0.294  0.135  0.250  1.0
  Si  Si35  1  0.794  0.365  0.250  1.0
[/CIF]
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