The material described by Mg13(NbH16)2 crystallizes in the tetragonal P4/mmm space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a body-centered cubic geometry to four equivalent H(1) and four equivalent H(4) atoms. In the second Mg site, Mg(2) is bonded in a body-centered cubic geometry to four equivalent H(2) and four equivalent H(3) atoms. In the third Mg site, Mg(3) is bonded in a body-centered cubic geometry to two equivalent H(1), two equivalent H(2), two equivalent H(3), and two equivalent H(4) atoms. In the fourth Mg site, Mg(4) is bonded in a body-centered cubic geometry to eight equivalent H(1) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a body-centered cubic geometry to eight equivalent H(3) atoms. In the second Nb site, Nb(2) is bonded in a body-centered cubic geometry to eight equivalent H(4) atoms. There are four inequivalent H sites. In the first H site, H(4) is bonded to one Mg(1), two equivalent Mg(3), and one Nb(2) atom to form HMg3Nb tetrahedra that share corners with four equivalent H(3)Mg3Nb tetrahedra, corners with four equivalent H(1)Mg4 tetrahedra, corners with six equivalent H(4)Mg3Nb tetrahedra, edges with two equivalent H(1)Mg4 tetrahedra, and edges with three equivalent H(4)Mg3Nb tetrahedra. In the second H site, H(1) is bonded to one Mg(1), one Mg(4), and two equivalent Mg(3) atoms to form HMg4 tetrahedra that share corners with two equivalent H(3)Mg3Nb tetrahedra, corners with four equivalent H(4)Mg3Nb tetrahedra, corners with six equivalent H(1)Mg4 tetrahedra,  an edgeedge with one H(3)Mg3Nb tetrahedra, edges with two equivalent H(4)Mg3Nb tetrahedra, and edges with three equivalent H(1)Mg4 tetrahedra. In the third H site, H(2) is bonded in a trigonal planar geometry to one Mg(2) and two equivalent Mg(3) atoms. In the fourth H site, H(3) is bonded to one Mg(2), two equivalent Mg(3), and one Nb(1) atom to form HMg3Nb tetrahedra that share corners with two equivalent H(1)Mg4 tetrahedra, corners with four equivalent H(4)Mg3Nb tetrahedra, corners with six equivalent H(3)Mg3Nb tetrahedra,  an edgeedge with one H(1)Mg4 tetrahedra, and edges with three equivalent H(3)Mg3Nb tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg13(NbH16)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.715
_cell_length_b   6.715
_cell_length_c   9.451
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   426.089
_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
  Mg  Mg0  1  0.000  0.500  0.500  1.0
  Mg  Mg1  1  0.500  0.000  0.000  1.0
  Mg  Mg2  1  0.745  0.255  0.244  1.0
  Mg  Mg3  1  0.255  0.745  0.756  1.0
  Mg  Mg4  1  0.745  0.745  0.244  1.0
  Mg  Mg5  1  0.255  0.255  0.756  1.0
  Mg  Mg6  1  0.500  0.000  0.500  1.0
  Mg  Mg7  1  0.000  0.500  0.000  1.0
  Mg  Mg8  1  0.255  0.745  0.244  1.0
  Mg  Mg9  1  0.745  0.255  0.756  1.0
  Mg  Mg10  1  0.745  0.745  0.756  1.0
  Mg  Mg11  1  0.255  0.255  0.244  1.0
  Mg  Mg12  1  0.000  0.000  0.500  1.0
  Nb  Nb13  1  0.000  0.000  0.000  1.0
  Nb  Nb14  1  0.500  0.500  0.500  1.0
  H  H15  1  0.742  0.000  0.630  1.0
  H  H16  1  0.220  0.500  0.137  1.0
  H  H17  1  0.000  0.258  0.370  1.0
  H  H18  1  0.500  0.780  0.863  1.0
  H  H19  1  0.000  0.742  0.370  1.0
  H  H20  1  0.500  0.220  0.863  1.0
  H  H21  1  0.258  0.000  0.630  1.0
  H  H22  1  0.780  0.500  0.137  1.0
  H  H23  1  0.258  0.000  0.370  1.0
  H  H24  1  0.780  0.500  0.863  1.0
  H  H25  1  0.000  0.742  0.630  1.0
  H  H26  1  0.500  0.220  0.137  1.0
  H  H27  1  0.000  0.258  0.630  1.0
  H  H28  1  0.500  0.780  0.137  1.0
  H  H29  1  0.742  0.000  0.370  1.0
  H  H30  1  0.220  0.500  0.863  1.0
  H  H31  1  0.233  0.000  0.881  1.0
  H  H32  1  0.738  0.500  0.383  1.0
  H  H33  1  0.500  0.262  0.617  1.0
  H  H34  1  0.000  0.767  0.119  1.0
  H  H35  1  0.500  0.738  0.617  1.0
  H  H36  1  0.000  0.233  0.119  1.0
  H  H37  1  0.767  0.000  0.881  1.0
  H  H38  1  0.262  0.500  0.383  1.0
  H  H39  1  0.767  0.000  0.119  1.0
  H  H40  1  0.262  0.500  0.617  1.0
  H  H41  1  0.500  0.738  0.383  1.0
  H  H42  1  0.000  0.233  0.881  1.0
  H  H43  1  0.500  0.262  0.383  1.0
  H  H44  1  0.000  0.767  0.881  1.0
  H  H45  1  0.233  0.000  0.119  1.0
  H  H46  1  0.738  0.500  0.617  1.0
[/CIF]
.
The material described by Mg13(NbH16)2 crystallizes in the tetragonal P4/mmm space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a body-centered cubic geometry to four equivalent H(1) and four equivalent H(4) atoms. In the second Mg site, Mg(2) is bonded in a body-centered cubic geometry to four equivalent H(2) and four equivalent H(3) atoms. In the third Mg site, Mg(3) is bonded in a body-centered cubic geometry to two equivalent H(1), two equivalent H(2), two equivalent H(3), and two equivalent H(4) atoms. In the fourth Mg site, Mg(4) is bonded in a body-centered cubic geometry to eight equivalent H(1) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a body-centered cubic geometry to eight equivalent H(3) atoms. In the second Nb site, Nb(2) is bonded in a body-centered cubic geometry to eight equivalent H(4) atoms. There are four inequivalent H sites. In the first H site, H(4) is bonded to one Mg(1), two equivalent Mg(3), and one Nb(2) atom to form HMg3Nb tetrahedra that share corners with four equivalent H(3)Mg3Nb tetrahedra, corners with four equivalent H(1)Mg4 tetrahedra, corners with six equivalent H(4)Mg3Nb tetrahedra, edges with two equivalent H(1)Mg4 tetrahedra, and edges with three equivalent H(4)Mg3Nb tetrahedra. In the second H site, H(1) is bonded to one Mg(1), one Mg(4), and two equivalent Mg(3) atoms to form HMg4 tetrahedra that share corners with two equivalent H(3)Mg3Nb tetrahedra, corners with four equivalent H(4)Mg3Nb tetrahedra, corners with six equivalent H(1)Mg4 tetrahedra,  an edgeedge with one H(3)Mg3Nb tetrahedra, edges with two equivalent H(4)Mg3Nb tetrahedra, and edges with three equivalent H(1)Mg4 tetrahedra. In the third H site, H(2) is bonded in a trigonal planar geometry to one Mg(2) and two equivalent Mg(3) atoms. In the fourth H site, H(3) is bonded to one Mg(2), two equivalent Mg(3), and one Nb(1) atom to form HMg3Nb tetrahedra that share corners with two equivalent H(1)Mg4 tetrahedra, corners with four equivalent H(4)Mg3Nb tetrahedra, corners with six equivalent H(3)Mg3Nb tetrahedra,  an edgeedge with one H(1)Mg4 tetrahedra, and edges with three equivalent H(3)Mg3Nb tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg13(NbH16)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.715
_cell_length_b   6.715
_cell_length_c   9.451
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   426.089
_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
  Mg  Mg0  1  0.000  0.500  0.500  1.0
  Mg  Mg1  1  0.500  0.000  0.000  1.0
  Mg  Mg2  1  0.745  0.255  0.244  1.0
  Mg  Mg3  1  0.255  0.745  0.756  1.0
  Mg  Mg4  1  0.745  0.745  0.244  1.0
  Mg  Mg5  1  0.255  0.255  0.756  1.0
  Mg  Mg6  1  0.500  0.000  0.500  1.0
  Mg  Mg7  1  0.000  0.500  0.000  1.0
  Mg  Mg8  1  0.255  0.745  0.244  1.0
  Mg  Mg9  1  0.745  0.255  0.756  1.0
  Mg  Mg10  1  0.745  0.745  0.756  1.0
  Mg  Mg11  1  0.255  0.255  0.244  1.0
  Mg  Mg12  1  0.000  0.000  0.500  1.0
  Nb  Nb13  1  0.000  0.000  0.000  1.0
  Nb  Nb14  1  0.500  0.500  0.500  1.0
  H  H15  1  0.742  0.000  0.630  1.0
  H  H16  1  0.220  0.500  0.137  1.0
  H  H17  1  0.000  0.258  0.370  1.0
  H  H18  1  0.500  0.780  0.863  1.0
  H  H19  1  0.000  0.742  0.370  1.0
  H  H20  1  0.500  0.220  0.863  1.0
  H  H21  1  0.258  0.000  0.630  1.0
  H  H22  1  0.780  0.500  0.137  1.0
  H  H23  1  0.258  0.000  0.370  1.0
  H  H24  1  0.780  0.500  0.863  1.0
  H  H25  1  0.000  0.742  0.630  1.0
  H  H26  1  0.500  0.220  0.137  1.0
  H  H27  1  0.000  0.258  0.630  1.0
  H  H28  1  0.500  0.780  0.137  1.0
  H  H29  1  0.742  0.000  0.370  1.0
  H  H30  1  0.220  0.500  0.863  1.0
  H  H31  1  0.233  0.000  0.881  1.0
  H  H32  1  0.738  0.500  0.383  1.0
  H  H33  1  0.500  0.262  0.617  1.0
  H  H34  1  0.000  0.767  0.119  1.0
  H  H35  1  0.500  0.738  0.617  1.0
  H  H36  1  0.000  0.233  0.119  1.0
  H  H37  1  0.767  0.000  0.881  1.0
  H  H38  1  0.262  0.500  0.383  1.0
  H  H39  1  0.767  0.000  0.119  1.0
  H  H40  1  0.262  0.500  0.617  1.0
  H  H41  1  0.500  0.738  0.383  1.0
  H  H42  1  0.000  0.233  0.881  1.0
  H  H43  1  0.500  0.262  0.383  1.0
  H  H44  1  0.000  0.767  0.881  1.0
  H  H45  1  0.233  0.000  0.119  1.0
  H  H46  1  0.738  0.500  0.617  1.0
[/CIF]
.