The compound described by Ca3Ta3N5 crystallizes in the triclinic P-1 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one N(3), one N(4), and two equivalent N(2) atoms to form distorted CaN4 trigonal pyramids that share corners with three equivalent Ta(3)N4 tetrahedra, corners with two equivalent Ta(1)N4 trigonal pyramids, and  an edgeedge with one Ca(1)N4 trigonal pyramid. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one N(2), one N(3), one N(4), two equivalent N(1), and two equivalent N(5) atoms. In the third Ca site, Ca(3) is bonded in a distorted rectangular see-saw-like geometry to one N(1), one N(2), and two equivalent N(3) atoms. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one N(1), one N(5), and two equivalent N(3) atoms to form distorted TaN4 trigonal pyramids that share corners with two equivalent Ta(3)N4 tetrahedra, corners with two equivalent Ca(1)N4 trigonal pyramids, and  an edgeedge with one Ta(1)N4 trigonal pyramid. In the second Ta site, Ta(2) is bonded in a distorted rectangular see-saw-like geometry to one N(1), one N(2), and two equivalent N(4) atoms. In the third Ta site, Ta(3) is bonded to one N(1), one N(2), one N(4), and one N(5) atom to form distorted TaN4 tetrahedra that share corners with two equivalent Ta(1)N4 trigonal pyramids and corners with three equivalent Ca(1)N4 trigonal pyramids. There are five inequivalent N sites. In the first N site, N(1) is bonded to one Ca(3), two equivalent Ca(2), one Ta(1), one Ta(2), and one Ta(3) atom to form distorted NCa3Ta3 octahedra that share corners with three equivalent N(4)Ca2Ta3 square pyramids,  an edgeedge with one N(1)Ca3Ta3 octahedra, and  an edgeedge with one N(4)Ca2Ta3 square pyramid. In the second N site, N(2) is bonded in a 6-coordinate geometry to one Ca(2), one Ca(3), two equivalent Ca(1), one Ta(2), and one Ta(3) atom. In the third N site, N(3) is bonded in a 6-coordinate geometry to one Ca(1), one Ca(2), two equivalent Ca(3), and two equivalent Ta(1) atoms. In the fourth N site, N(4) is bonded to one Ca(1), one Ca(2), one Ta(3), and two equivalent Ta(2) atoms to form distorted NCa2Ta3 square pyramids that share corners with three equivalent N(1)Ca3Ta3 octahedra,  an edgeedge with one N(1)Ca3Ta3 octahedra, and  an edgeedge with one N(4)Ca2Ta3 square pyramid. The corner-sharing octahedral tilt angles range from 24-58°. In the fifth N site, N(5) is bonded in a 4-coordinate geometry to two equivalent Ca(2), one Ta(1), and one Ta(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca3Ta3N5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.970
_cell_length_b   8.090
_cell_length_c   8.411
_cell_angle_alpha   109.821
_cell_angle_beta   106.217
_cell_angle_gamma   105.056
_symmetry_Int_Tables_number   1
_cell_volume   337.539
_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
  Ca  Ca0  1  0.716  0.427  0.599  1.0
  Ca  Ca1  1  0.284  0.573  0.401  1.0
  Ca  Ca2  1  0.662  0.845  0.870  1.0
  Ca  Ca3  1  0.338  0.155  0.130  1.0
  Ca  Ca4  1  0.702  0.655  0.221  1.0
  Ca  Ca5  1  0.298  0.345  0.779  1.0
  Ta  Ta6  1  0.873  0.293  0.935  1.0
  Ta  Ta7  1  0.127  0.707  0.065  1.0
  Ta  Ta8  1  0.732  0.993  0.558  1.0
  Ta  Ta9  1  0.268  0.007  0.442  1.0
  Ta  Ta10  1  0.109  0.869  0.697  1.0
  Ta  Ta11  1  0.891  0.131  0.303  1.0
  N  N12  1  0.027  0.083  0.837  1.0
  N  N13  1  0.973  0.917  0.163  1.0
  N  N14  1  0.741  0.699  0.537  1.0
  N  N15  1  0.259  0.301  0.463  1.0
  N  N16  1  0.762  0.518  0.920  1.0
  N  N17  1  0.238  0.482  0.080  1.0
  N  N18  1  0.422  0.916  0.637  1.0
  N  N19  1  0.578  0.084  0.363  1.0
  N  N20  1  0.243  0.781  0.892  1.0
  N  N21  1  0.757  0.219  0.108  1.0
[/CIF]
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The compound described by Ca3Ta3N5 crystallizes in the triclinic P-1 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one N(3), one N(4), and two equivalent N(2) atoms to form distorted CaN4 trigonal pyramids that share corners with three equivalent Ta(3)N4 tetrahedra, corners with two equivalent Ta(1)N4 trigonal pyramids, and  an edgeedge with one Ca(1)N4 trigonal pyramid. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one N(2), one N(3), one N(4), two equivalent N(1), and two equivalent N(5) atoms. In the third Ca site, Ca(3) is bonded in a distorted rectangular see-saw-like geometry to one N(1), one N(2), and two equivalent N(3) atoms. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one N(1), one N(5), and two equivalent N(3) atoms to form distorted TaN4 trigonal pyramids that share corners with two equivalent Ta(3)N4 tetrahedra, corners with two equivalent Ca(1)N4 trigonal pyramids, and  an edgeedge with one Ta(1)N4 trigonal pyramid. In the second Ta site, Ta(2) is bonded in a distorted rectangular see-saw-like geometry to one N(1), one N(2), and two equivalent N(4) atoms. In the third Ta site, Ta(3) is bonded to one N(1), one N(2), one N(4), and one N(5) atom to form distorted TaN4 tetrahedra that share corners with two equivalent Ta(1)N4 trigonal pyramids and corners with three equivalent Ca(1)N4 trigonal pyramids. There are five inequivalent N sites. In the first N site, N(1) is bonded to one Ca(3), two equivalent Ca(2), one Ta(1), one Ta(2), and one Ta(3) atom to form distorted NCa3Ta3 octahedra that share corners with three equivalent N(4)Ca2Ta3 square pyramids,  an edgeedge with one N(1)Ca3Ta3 octahedra, and  an edgeedge with one N(4)Ca2Ta3 square pyramid. In the second N site, N(2) is bonded in a 6-coordinate geometry to one Ca(2), one Ca(3), two equivalent Ca(1), one Ta(2), and one Ta(3) atom. In the third N site, N(3) is bonded in a 6-coordinate geometry to one Ca(1), one Ca(2), two equivalent Ca(3), and two equivalent Ta(1) atoms. In the fourth N site, N(4) is bonded to one Ca(1), one Ca(2), one Ta(3), and two equivalent Ta(2) atoms to form distorted NCa2Ta3 square pyramids that share corners with three equivalent N(1)Ca3Ta3 octahedra,  an edgeedge with one N(1)Ca3Ta3 octahedra, and  an edgeedge with one N(4)Ca2Ta3 square pyramid. The corner-sharing octahedral tilt angles range from 24-58°. In the fifth N site, N(5) is bonded in a 4-coordinate geometry to two equivalent Ca(2), one Ta(1), and one Ta(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca3Ta3N5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.970
_cell_length_b   8.090
_cell_length_c   8.411
_cell_angle_alpha   109.821
_cell_angle_beta   106.217
_cell_angle_gamma   105.056
_symmetry_Int_Tables_number   1
_cell_volume   337.539
_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
  Ca  Ca0  1  0.716  0.427  0.599  1.0
  Ca  Ca1  1  0.284  0.573  0.401  1.0
  Ca  Ca2  1  0.662  0.845  0.870  1.0
  Ca  Ca3  1  0.338  0.155  0.130  1.0
  Ca  Ca4  1  0.702  0.655  0.221  1.0
  Ca  Ca5  1  0.298  0.345  0.779  1.0
  Ta  Ta6  1  0.873  0.293  0.935  1.0
  Ta  Ta7  1  0.127  0.707  0.065  1.0
  Ta  Ta8  1  0.732  0.993  0.558  1.0
  Ta  Ta9  1  0.268  0.007  0.442  1.0
  Ta  Ta10  1  0.109  0.869  0.697  1.0
  Ta  Ta11  1  0.891  0.131  0.303  1.0
  N  N12  1  0.027  0.083  0.837  1.0
  N  N13  1  0.973  0.917  0.163  1.0
  N  N14  1  0.741  0.699  0.537  1.0
  N  N15  1  0.259  0.301  0.463  1.0
  N  N16  1  0.762  0.518  0.920  1.0
  N  N17  1  0.238  0.482  0.080  1.0
  N  N18  1  0.422  0.916  0.637  1.0
  N  N19  1  0.578  0.084  0.363  1.0
  N  N20  1  0.243  0.781  0.892  1.0
  N  N21  1  0.757  0.219  0.108  1.0
[/CIF]
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