The crystal structure described by Sr4Nb5O15 crystallizes in the monoclinic C2/m space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to one O(5), one O(6), two equivalent O(1), two equivalent O(2), two equivalent O(4), and four equivalent O(3) atoms to form SrO12 cuboctahedra that share corners with five equivalent Sr(1)O12 cuboctahedra, corners with five equivalent Sr(2)O12 cuboctahedra,  a faceface with one Sr(1)O12 cuboctahedra, faces with three equivalent Sr(2)O12 cuboctahedra, faces with two equivalent Nb(3)O6 octahedra, faces with three equivalent Nb(1)O6 octahedra, and faces with three equivalent Nb(2)O6 octahedra. In the second Sr site, Sr(2) is bonded to one O(4), two equivalent O(2), two equivalent O(3), three equivalent O(5), and four equivalent O(1) atoms to form SrO12 cuboctahedra that share corners with four equivalent Sr(2)O12 cuboctahedra, corners with five equivalent Sr(1)O12 cuboctahedra, faces with two equivalent Sr(2)O12 cuboctahedra, faces with three equivalent Sr(1)O12 cuboctahedra,  a faceface with one Nb(3)O6 octahedra, faces with three equivalent Nb(2)O6 octahedra, and faces with four equivalent Nb(1)O6 octahedra. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with three equivalent Nb(2)O6 octahedra, faces with three equivalent Sr(1)O12 cuboctahedra, and faces with four equivalent Sr(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the second Nb site, Nb(2) is bonded to one O(5), one O(6), two equivalent O(1), and two equivalent O(3) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, corners with three equivalent Nb(1)O6 octahedra, faces with three equivalent Sr(1)O12 cuboctahedra, and faces with three equivalent Sr(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the third Nb site, Nb(3) is bonded to two equivalent O(4) and four equivalent O(3) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, faces with two equivalent Sr(2)O12 cuboctahedra, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 5°. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), two equivalent Sr(2), one Nb(1), and one Nb(2) atom to form a mixture of distorted edge, corner, and face-sharing OSr3Nb2 square pyramids. In the second O site, O(2) is bonded in a distorted linear geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded to one Sr(2), two equivalent Sr(1), one Nb(2), and one Nb(3) atom to form a mixture of distorted edge, corner, and face-sharing OSr3Nb2 square pyramids. In the fourth O site, O(4) is bonded to one Sr(2), two equivalent Sr(1), one Nb(1), and one Nb(3) atom to form a mixture of distorted edge, corner, and face-sharing OSr3Nb2 square pyramids. In the fifth O site, O(5) is bonded in a distorted linear geometry to one Sr(1), three equivalent Sr(2), one Nb(1), and one Nb(2) atom. In the sixth O site, O(6) is bonded in a distorted square co-planar geometry to two equivalent Sr(1) and two equivalent Nb(2) atoms. is represented by the CIF file [CIF]
data_Sr4Nb5O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.029
_cell_length_b   9.029
_cell_length_c   6.995
_cell_angle_alpha   75.051
_cell_angle_beta   75.051
_cell_angle_gamma   36.870
_symmetry_Int_Tables_number   1
_cell_volume   329.244
_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
  Sr  Sr0  1  0.597  0.597  0.608  1.0
  Sr  Sr1  1  0.197  0.197  0.198  1.0
  Sr  Sr2  1  0.803  0.803  0.802  1.0
  Sr  Sr3  1  0.403  0.403  0.392  1.0
  Nb  Nb4  1  0.802  0.802  0.296  1.0
  Nb  Nb5  1  0.598  0.598  0.100  1.0
  Nb  Nb6  1  0.198  0.198  0.704  1.0
  Nb  Nb7  1  0.402  0.402  0.900  1.0
  Nb  Nb8  1  0.000  0.000  0.500  1.0
  O  O9  1  0.101  0.588  0.101  1.0
  O  O10  1  0.899  0.412  0.899  1.0
  O  O11  1  0.500  0.000  0.500  1.0
  O  O12  1  0.692  0.205  0.692  1.0
  O  O13  1  0.308  0.795  0.308  1.0
  O  O14  1  0.000  0.500  0.500  1.0
  O  O15  1  0.795  0.308  0.308  1.0
  O  O16  1  0.412  0.899  0.899  1.0
  O  O17  1  0.588  0.101  0.101  1.0
  O  O18  1  0.205  0.692  0.692  1.0
  O  O19  1  0.897  0.897  0.409  1.0
  O  O20  1  0.699  0.699  0.203  1.0
  O  O21  1  0.301  0.301  0.797  1.0
  O  O22  1  0.500  0.500  0.000  1.0
  O  O23  1  0.103  0.103  0.591  1.0
[/CIF]
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The crystal structure described by Sr4Nb5O15 crystallizes in the monoclinic C2/m space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to one O(5), one O(6), two equivalent O(1), two equivalent O(2), two equivalent O(4), and four equivalent O(3) atoms to form SrO12 cuboctahedra that share corners with five equivalent Sr(1)O12 cuboctahedra, corners with five equivalent Sr(2)O12 cuboctahedra,  a faceface with one Sr(1)O12 cuboctahedra, faces with three equivalent Sr(2)O12 cuboctahedra, faces with two equivalent Nb(3)O6 octahedra, faces with three equivalent Nb(1)O6 octahedra, and faces with three equivalent Nb(2)O6 octahedra. In the second Sr site, Sr(2) is bonded to one O(4), two equivalent O(2), two equivalent O(3), three equivalent O(5), and four equivalent O(1) atoms to form SrO12 cuboctahedra that share corners with four equivalent Sr(2)O12 cuboctahedra, corners with five equivalent Sr(1)O12 cuboctahedra, faces with two equivalent Sr(2)O12 cuboctahedra, faces with three equivalent Sr(1)O12 cuboctahedra,  a faceface with one Nb(3)O6 octahedra, faces with three equivalent Nb(2)O6 octahedra, and faces with four equivalent Nb(1)O6 octahedra. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with three equivalent Nb(2)O6 octahedra, faces with three equivalent Sr(1)O12 cuboctahedra, and faces with four equivalent Sr(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the second Nb site, Nb(2) is bonded to one O(5), one O(6), two equivalent O(1), and two equivalent O(3) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, corners with three equivalent Nb(1)O6 octahedra, faces with three equivalent Sr(1)O12 cuboctahedra, and faces with three equivalent Sr(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the third Nb site, Nb(3) is bonded to two equivalent O(4) and four equivalent O(3) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, faces with two equivalent Sr(2)O12 cuboctahedra, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 5°. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), two equivalent Sr(2), one Nb(1), and one Nb(2) atom to form a mixture of distorted edge, corner, and face-sharing OSr3Nb2 square pyramids. In the second O site, O(2) is bonded in a distorted linear geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded to one Sr(2), two equivalent Sr(1), one Nb(2), and one Nb(3) atom to form a mixture of distorted edge, corner, and face-sharing OSr3Nb2 square pyramids. In the fourth O site, O(4) is bonded to one Sr(2), two equivalent Sr(1), one Nb(1), and one Nb(3) atom to form a mixture of distorted edge, corner, and face-sharing OSr3Nb2 square pyramids. In the fifth O site, O(5) is bonded in a distorted linear geometry to one Sr(1), three equivalent Sr(2), one Nb(1), and one Nb(2) atom. In the sixth O site, O(6) is bonded in a distorted square co-planar geometry to two equivalent Sr(1) and two equivalent Nb(2) atoms. is represented by the CIF file [CIF]
data_Sr4Nb5O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.029
_cell_length_b   9.029
_cell_length_c   6.995
_cell_angle_alpha   75.051
_cell_angle_beta   75.051
_cell_angle_gamma   36.870
_symmetry_Int_Tables_number   1
_cell_volume   329.244
_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
  Sr  Sr0  1  0.597  0.597  0.608  1.0
  Sr  Sr1  1  0.197  0.197  0.198  1.0
  Sr  Sr2  1  0.803  0.803  0.802  1.0
  Sr  Sr3  1  0.403  0.403  0.392  1.0
  Nb  Nb4  1  0.802  0.802  0.296  1.0
  Nb  Nb5  1  0.598  0.598  0.100  1.0
  Nb  Nb6  1  0.198  0.198  0.704  1.0
  Nb  Nb7  1  0.402  0.402  0.900  1.0
  Nb  Nb8  1  0.000  0.000  0.500  1.0
  O  O9  1  0.101  0.588  0.101  1.0
  O  O10  1  0.899  0.412  0.899  1.0
  O  O11  1  0.500  0.000  0.500  1.0
  O  O12  1  0.692  0.205  0.692  1.0
  O  O13  1  0.308  0.795  0.308  1.0
  O  O14  1  0.000  0.500  0.500  1.0
  O  O15  1  0.795  0.308  0.308  1.0
  O  O16  1  0.412  0.899  0.899  1.0
  O  O17  1  0.588  0.101  0.101  1.0
  O  O18  1  0.205  0.692  0.692  1.0
  O  O19  1  0.897  0.897  0.409  1.0
  O  O20  1  0.699  0.699  0.203  1.0
  O  O21  1  0.301  0.301  0.797  1.0
  O  O22  1  0.500  0.500  0.000  1.0
  O  O23  1  0.103  0.103  0.591  1.0
[/CIF]
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