The material structure described by BaO is Molybdenum Carbide MAX Phase-like structured and crystallizes in the orthorhombic Amm2 space group. There are nine inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to six equivalent O(5) atoms to form a mixture of distorted edge and corner-sharing BaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 1°. In the second Ba site, Ba(2) is bonded to three equivalent O(6) and three equivalent O(8) atoms to form a mixture of distorted edge and corner-sharing BaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 0-1°. In the third Ba site, Ba(3) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form a mixture of edge and corner-sharing BaO6 octahedra. The corner-sharing octahedra are not tilted. In the fourth Ba site, Ba(4) is bonded to three equivalent O(3) and three equivalent O(5) atoms to form a mixture of edge and corner-sharing BaO6 octahedra. The corner-sharing octahedra are not tilted. In the fifth Ba site, Ba(5) is bonded to three equivalent O(1) and three equivalent O(6) atoms to form a mixture of edge and corner-sharing BaO6 octahedra. In the sixth Ba site, Ba(6) is bonded to three equivalent O(4) and three equivalent O(7) atoms to form a mixture of edge and corner-sharing BaO6 octahedra. The corner-sharing octahedra are not tilted. In the seventh Ba site, Ba(7) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form a mixture of edge and corner-sharing BaO6 octahedra. The corner-sharing octahedra are not tilted. In the eighth Ba site, Ba(8) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form a mixture of distorted edge and corner-sharing BaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 0-1°. In the ninth Ba site, Ba(9) is bonded to six equivalent O(4) atoms to form a mixture of distorted edge and corner-sharing BaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 1°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ba(5) and three equivalent Ba(8) atoms to form a mixture of edge, corner, and face-sharing OBa6 octahedra. The corner-sharing octahedral tilt angles range from 0-48°. In the second O site, O(2) is bonded to three equivalent Ba(7) and three equivalent Ba(8) atoms to form a mixture of edge, corner, and face-sharing OBa6 octahedra. The corner-sharing octahedral tilt angles range from 0-48°. In the third O site, O(3) is bonded to three equivalent Ba(4) and three equivalent Ba(7) atoms to form a mixture of edge and corner-sharing OBa6 octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded to three equivalent Ba(6) and three equivalent Ba(9) atoms to form a mixture of edge, corner, and face-sharing OBa6 octahedra. The corner-sharing octahedral tilt angles range from 0-48°. In the fifth O site, O(5) is bonded to three equivalent Ba(1) and three equivalent Ba(4) atoms to form a mixture of edge, corner, and face-sharing OBa6 octahedra. The corner-sharing octahedral tilt angles range from 0-47°. In the sixth O site, O(6) is bonded to three equivalent Ba(2) and three equivalent Ba(5) atoms to form a mixture of edge, corner, and face-sharing OBa6 octahedra. The corner-sharing octahedral tilt angles range from 0-48°. In the seventh O site, O(7) is bonded to three equivalent Ba(3) and three equivalent Ba(6) atoms to form a mixture of edge and corner-sharing OBa6 octahedra. The corner-sharing octahedra are not tilted. In the eighth O site, O(8) is bonded to three equivalent Ba(2) and three equivalent Ba(3) atoms to form a mixture of edge, corner, and face-sharing OBa6 octahedra. The corner-sharing octahedral tilt angles range from 0-48°. is represented by the Crystallographic Information File (CIF) [CIF]
data_BaO
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.894
_cell_length_b   52.349
_cell_length_c   3.893
_cell_angle_alpha   90.000
_cell_angle_beta   120.005
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   687.221
_cell_formula_units_Z   16
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  0.859  0.250  0.679  1.0
  Ba  Ba1  1  0.155  0.563  0.327  1.0
  Ba  Ba2  1  0.155  0.937  0.327  1.0
  Ba  Ba3  1  0.479  0.625  0.988  1.0
  Ba  Ba4  1  0.479  0.875  0.988  1.0
  Ba  Ba5  1  0.191  0.187  0.344  1.0
  Ba  Ba6  1  0.191  0.313  0.344  1.0
  Ba  Ba7  1  0.500  1.000  0.999  1.0
  Ba  Ba8  1  0.500  0.500  0.999  1.0
  Ba  Ba9  1  0.809  0.687  0.653  1.0
  Ba  Ba10  1  0.809  0.813  0.653  1.0
  Ba  Ba11  1  0.522  0.125  0.009  1.0
  Ba  Ba12  1  0.522  0.375  0.009  1.0
  Ba  Ba13  1  0.846  0.062  0.672  1.0
  Ba  Ba14  1  0.846  0.438  0.672  1.0
  Ba  Ba15  1  0.141  0.750  0.321  1.0
  O  O16  1  0.170  0.031  0.334  1.0
  O  O17  1  0.188  0.094  0.343  1.0
  O  O18  1  0.856  0.156  0.678  1.0
  O  O19  1  0.188  0.406  0.343  1.0
  O  O20  1  0.856  0.344  0.678  1.0
  O  O21  1  0.170  0.469  0.334  1.0
  O  O22  1  0.474  0.718  0.987  1.0
  O  O23  1  0.474  0.782  0.987  1.0
  O  O24  1  0.526  0.218  0.013  1.0
  O  O25  1  0.830  0.531  0.665  1.0
  O  O26  1  0.830  0.969  0.665  1.0
  O  O27  1  0.144  0.656  0.322  1.0
  O  O28  1  0.526  0.282  0.013  1.0
  O  O29  1  0.812  0.594  0.656  1.0
  O  O30  1  0.812  0.906  0.656  1.0
  O  O31  1  0.144  0.844  0.322  1.0
[/CIF]
.
The material structure described by BaO is Molybdenum Carbide MAX Phase-like structured and crystallizes in the orthorhombic Amm2 space group. There are nine inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to six equivalent O(5) atoms to form a mixture of distorted edge and corner-sharing BaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 1°. In the second Ba site, Ba(2) is bonded to three equivalent O(6) and three equivalent O(8) atoms to form a mixture of distorted edge and corner-sharing BaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 0-1°. In the third Ba site, Ba(3) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form a mixture of edge and corner-sharing BaO6 octahedra. The corner-sharing octahedra are not tilted. In the fourth Ba site, Ba(4) is bonded to three equivalent O(3) and three equivalent O(5) atoms to form a mixture of edge and corner-sharing BaO6 octahedra. The corner-sharing octahedra are not tilted. In the fifth Ba site, Ba(5) is bonded to three equivalent O(1) and three equivalent O(6) atoms to form a mixture of edge and corner-sharing BaO6 octahedra. In the sixth Ba site, Ba(6) is bonded to three equivalent O(4) and three equivalent O(7) atoms to form a mixture of edge and corner-sharing BaO6 octahedra. The corner-sharing octahedra are not tilted. In the seventh Ba site, Ba(7) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form a mixture of edge and corner-sharing BaO6 octahedra. The corner-sharing octahedra are not tilted. In the eighth Ba site, Ba(8) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form a mixture of distorted edge and corner-sharing BaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 0-1°. In the ninth Ba site, Ba(9) is bonded to six equivalent O(4) atoms to form a mixture of distorted edge and corner-sharing BaO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 1°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ba(5) and three equivalent Ba(8) atoms to form a mixture of edge, corner, and face-sharing OBa6 octahedra. The corner-sharing octahedral tilt angles range from 0-48°. In the second O site, O(2) is bonded to three equivalent Ba(7) and three equivalent Ba(8) atoms to form a mixture of edge, corner, and face-sharing OBa6 octahedra. The corner-sharing octahedral tilt angles range from 0-48°. In the third O site, O(3) is bonded to three equivalent Ba(4) and three equivalent Ba(7) atoms to form a mixture of edge and corner-sharing OBa6 octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded to three equivalent Ba(6) and three equivalent Ba(9) atoms to form a mixture of edge, corner, and face-sharing OBa6 octahedra. The corner-sharing octahedral tilt angles range from 0-48°. In the fifth O site, O(5) is bonded to three equivalent Ba(1) and three equivalent Ba(4) atoms to form a mixture of edge, corner, and face-sharing OBa6 octahedra. The corner-sharing octahedral tilt angles range from 0-47°. In the sixth O site, O(6) is bonded to three equivalent Ba(2) and three equivalent Ba(5) atoms to form a mixture of edge, corner, and face-sharing OBa6 octahedra. The corner-sharing octahedral tilt angles range from 0-48°. In the seventh O site, O(7) is bonded to three equivalent Ba(3) and three equivalent Ba(6) atoms to form a mixture of edge and corner-sharing OBa6 octahedra. The corner-sharing octahedra are not tilted. In the eighth O site, O(8) is bonded to three equivalent Ba(2) and three equivalent Ba(3) atoms to form a mixture of edge, corner, and face-sharing OBa6 octahedra. The corner-sharing octahedral tilt angles range from 0-48°. is represented by the Crystallographic Information File (CIF) [CIF]
data_BaO
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.894
_cell_length_b   52.349
_cell_length_c   3.893
_cell_angle_alpha   90.000
_cell_angle_beta   120.005
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   687.221
_cell_formula_units_Z   16
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  0.859  0.250  0.679  1.0
  Ba  Ba1  1  0.155  0.563  0.327  1.0
  Ba  Ba2  1  0.155  0.937  0.327  1.0
  Ba  Ba3  1  0.479  0.625  0.988  1.0
  Ba  Ba4  1  0.479  0.875  0.988  1.0
  Ba  Ba5  1  0.191  0.187  0.344  1.0
  Ba  Ba6  1  0.191  0.313  0.344  1.0
  Ba  Ba7  1  0.500  1.000  0.999  1.0
  Ba  Ba8  1  0.500  0.500  0.999  1.0
  Ba  Ba9  1  0.809  0.687  0.653  1.0
  Ba  Ba10  1  0.809  0.813  0.653  1.0
  Ba  Ba11  1  0.522  0.125  0.009  1.0
  Ba  Ba12  1  0.522  0.375  0.009  1.0
  Ba  Ba13  1  0.846  0.062  0.672  1.0
  Ba  Ba14  1  0.846  0.438  0.672  1.0
  Ba  Ba15  1  0.141  0.750  0.321  1.0
  O  O16  1  0.170  0.031  0.334  1.0
  O  O17  1  0.188  0.094  0.343  1.0
  O  O18  1  0.856  0.156  0.678  1.0
  O  O19  1  0.188  0.406  0.343  1.0
  O  O20  1  0.856  0.344  0.678  1.0
  O  O21  1  0.170  0.469  0.334  1.0
  O  O22  1  0.474  0.718  0.987  1.0
  O  O23  1  0.474  0.782  0.987  1.0
  O  O24  1  0.526  0.218  0.013  1.0
  O  O25  1  0.830  0.531  0.665  1.0
  O  O26  1  0.830  0.969  0.665  1.0
  O  O27  1  0.144  0.656  0.322  1.0
  O  O28  1  0.526  0.282  0.013  1.0
  O  O29  1  0.812  0.594  0.656  1.0
  O  O30  1  0.812  0.906  0.656  1.0
  O  O31  1  0.144  0.844  0.322  1.0
[/CIF]
.