The compound described by K2MgNb2P2(CO7)2 crystallizes in the triclinic P1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(1), one O(14), one O(2), one O(3), one O(6), one O(7), and two equivalent O(5) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(12), one O(13), one O(14), one O(8), one O(9), and two equivalent O(10) atoms. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(6) atom to form distorted MgO5 square pyramids that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, and  a faceface with one Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 56°. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form distorted NbO6 octahedra that share  a cornercorner with one Mg(1)O5 square pyramid, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  a faceface with one Mg(1)O5 square pyramid. In the second Nb site, Nb(2) is bonded to one O(10), one O(11), one O(12), one O(13), one O(7), and one O(9) atom to form NbO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra and corners with two equivalent P(2)O4 tetrahedra. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(14), one O(2), and one O(3) atom. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(1), one O(12), and one O(13) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(4), one O(5), one O(7), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, and  a cornercorner with one Mg(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 29-54°. In the second P site, P(2) is bonded to one O(10), one O(11), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, and  a cornercorner with one Mg(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 32-56°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one Mg(1), and one C(2) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one Mg(1), one Nb(1), and one C(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one K(1), one Mg(1), one Nb(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Mg(1), one Nb(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent K(1), one Nb(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one K(1), one Mg(1), one Nb(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one K(1), one Nb(2), and one P(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one K(2), one Nb(1), and one P(2) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one K(2), one Nb(2), and one P(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to two equivalent K(2), one Nb(2), and one P(2) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(2) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one K(2), one Nb(2), and one C(2) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one K(2), one Nb(2), and one C(2) atom. In the fourteenth O site, O(14) is bonded in a 1-coordinate geometry to one K(1), one K(2), and one C(1) atom. is represented by the CIF file [CIF]
data_K2MgNb2P2(CO7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.628
_cell_length_b   6.782
_cell_length_c   5.394
_cell_angle_alpha   84.692
_cell_angle_beta   87.064
_cell_angle_gamma   86.318
_symmetry_Int_Tables_number   1
_cell_volume   349.646
_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
  K  K0  1  0.196  0.476  0.297  1.0
  K  K1  1  0.772  0.928  0.769  1.0
  Mg  Mg2  1  0.215  0.978  0.176  1.0
  Nb  Nb3  1  0.365  0.776  0.786  1.0
  Nb  Nb4  1  0.654  0.271  0.221  1.0
  P  P5  1  0.418  0.271  0.745  1.0
  P  P6  1  0.572  0.771  0.302  1.0
  C  C7  1  0.099  0.776  0.697  1.0
  C  C8  1  0.923  0.203  0.236  1.0
  O  O9  1  0.055  0.163  0.252  1.0
  O  O10  1  0.145  0.795  0.926  1.0
  O  O11  1  0.197  0.819  0.516  1.0
  O  O12  1  0.326  0.096  0.856  1.0
  O  O13  1  0.328  0.467  0.780  1.0
  O  O14  1  0.426  0.796  0.184  1.0
  O  O15  1  0.453  0.251  0.464  1.0
  O  O16  1  0.555  0.760  0.592  1.0
  O  O17  1  0.552  0.266  0.889  1.0
  O  O18  1  0.662  0.949  0.221  1.0
  O  O19  1  0.649  0.578  0.221  1.0
  O  O20  1  0.840  0.212  0.436  1.0
  O  O21  1  0.862  0.237  0.027  1.0
  O  O22  1  0.987  0.709  0.657  1.0
[/CIF]
.
The compound described by K2MgNb2P2(CO7)2 crystallizes in the triclinic P1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(1), one O(14), one O(2), one O(3), one O(6), one O(7), and two equivalent O(5) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(12), one O(13), one O(14), one O(8), one O(9), and two equivalent O(10) atoms. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(6) atom to form distorted MgO5 square pyramids that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, and  a faceface with one Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 56°. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form distorted NbO6 octahedra that share  a cornercorner with one Mg(1)O5 square pyramid, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  a faceface with one Mg(1)O5 square pyramid. In the second Nb site, Nb(2) is bonded to one O(10), one O(11), one O(12), one O(13), one O(7), and one O(9) atom to form NbO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra and corners with two equivalent P(2)O4 tetrahedra. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(14), one O(2), and one O(3) atom. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(1), one O(12), and one O(13) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(4), one O(5), one O(7), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, and  a cornercorner with one Mg(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 29-54°. In the second P site, P(2) is bonded to one O(10), one O(11), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, and  a cornercorner with one Mg(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 32-56°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one Mg(1), and one C(2) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one Mg(1), one Nb(1), and one C(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one K(1), one Mg(1), one Nb(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Mg(1), one Nb(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent K(1), one Nb(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one K(1), one Mg(1), one Nb(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one K(1), one Nb(2), and one P(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one K(2), one Nb(1), and one P(2) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one K(2), one Nb(2), and one P(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to two equivalent K(2), one Nb(2), and one P(2) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(2) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one K(2), one Nb(2), and one C(2) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one K(2), one Nb(2), and one C(2) atom. In the fourteenth O site, O(14) is bonded in a 1-coordinate geometry to one K(1), one K(2), and one C(1) atom. is represented by the CIF file [CIF]
data_K2MgNb2P2(CO7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.628
_cell_length_b   6.782
_cell_length_c   5.394
_cell_angle_alpha   84.692
_cell_angle_beta   87.064
_cell_angle_gamma   86.318
_symmetry_Int_Tables_number   1
_cell_volume   349.646
_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
  K  K0  1  0.196  0.476  0.297  1.0
  K  K1  1  0.772  0.928  0.769  1.0
  Mg  Mg2  1  0.215  0.978  0.176  1.0
  Nb  Nb3  1  0.365  0.776  0.786  1.0
  Nb  Nb4  1  0.654  0.271  0.221  1.0
  P  P5  1  0.418  0.271  0.745  1.0
  P  P6  1  0.572  0.771  0.302  1.0
  C  C7  1  0.099  0.776  0.697  1.0
  C  C8  1  0.923  0.203  0.236  1.0
  O  O9  1  0.055  0.163  0.252  1.0
  O  O10  1  0.145  0.795  0.926  1.0
  O  O11  1  0.197  0.819  0.516  1.0
  O  O12  1  0.326  0.096  0.856  1.0
  O  O13  1  0.328  0.467  0.780  1.0
  O  O14  1  0.426  0.796  0.184  1.0
  O  O15  1  0.453  0.251  0.464  1.0
  O  O16  1  0.555  0.760  0.592  1.0
  O  O17  1  0.552  0.266  0.889  1.0
  O  O18  1  0.662  0.949  0.221  1.0
  O  O19  1  0.649  0.578  0.221  1.0
  O  O20  1  0.840  0.212  0.436  1.0
  O  O21  1  0.862  0.237  0.027  1.0
  O  O22  1  0.987  0.709  0.657  1.0
[/CIF]
.