The crystal structure described by UMnAl is Frank-Kasper $\mu$ Phase-derived structured and crystallizes in the monoclinic Pm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 15-coordinate geometry to three equivalent U(2), one Mn(1), one Mn(2), three equivalent Mn(3), one Al(4), two equivalent Al(1), two equivalent Al(2), and two equivalent Al(3) atoms. In the second U site, U(2) is bonded in a 16-coordinate geometry to one U(2), three equivalent U(1), two equivalent Mn(1), two equivalent Mn(2), three equivalent Mn(3), one Al(1), one Al(2), one Al(3), and two equivalent Al(4) atoms. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent U(1), four equivalent U(2), two equivalent Mn(2), two equivalent Mn(3), and two equivalent Al(4) atoms to form MnU6Mn4Al2 cuboctahedra that share corners with two equivalent Al(2)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(1)U6Mn4Al2 cuboctahedra, corners with four equivalent Al(1)U6Mn2Al4 cuboctahedra, corners with four equivalent Al(3)U6Mn2Al4 cuboctahedra, edges with two equivalent Mn(1)U6Mn4Al2 cuboctahedra, edges with four equivalent Al(2)U6Mn2Al4 cuboctahedra, faces with two equivalent Al(1)U6Mn2Al4 cuboctahedra, faces with two equivalent Al(3)U6Mn2Al4 cuboctahedra, faces with four equivalent Mn(2)U6Mn4Al2 cuboctahedra, faces with four equivalent Al(4)U6Mn6 cuboctahedra, and faces with six equivalent Mn(3)U6Mn2Al4 cuboctahedra. In the second Mn site, Mn(2) is bonded to two equivalent U(1), four equivalent U(2), two equivalent Mn(1), two equivalent Mn(3), and two equivalent Al(4) atoms to form MnU6Mn4Al2 cuboctahedra that share corners with two equivalent Al(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(2)U6Mn4Al2 cuboctahedra, corners with four equivalent Al(1)U6Mn2Al4 cuboctahedra, corners with four equivalent Al(2)U6Mn2Al4 cuboctahedra, edges with two equivalent Mn(2)U6Mn4Al2 cuboctahedra, edges with four equivalent Al(3)U6Mn2Al4 cuboctahedra, faces with two equivalent Al(1)U6Mn2Al4 cuboctahedra, faces with two equivalent Al(2)U6Mn2Al4 cuboctahedra, faces with four equivalent Mn(1)U6Mn4Al2 cuboctahedra, faces with four equivalent Al(4)U6Mn6 cuboctahedra, and faces with six equivalent Mn(3)U6Mn2Al4 cuboctahedra. In the third Mn site, Mn(3) is bonded to three equivalent U(1), three equivalent U(2), one Mn(1), one Mn(2), one Al(1), one Al(2), one Al(3), and one Al(4) atom to form MnU6Mn2Al4 cuboctahedra that share corners with two equivalent Mn(1)U6Mn4Al2 cuboctahedra, corners with two equivalent Mn(2)U6Mn4Al2 cuboctahedra, corners with two equivalent Al(1)U6Mn2Al4 cuboctahedra, corners with two equivalent Al(2)U6Mn2Al4 cuboctahedra, corners with two equivalent Al(3)U6Mn2Al4 cuboctahedra, corners with two equivalent Al(4)U6Mn6 cuboctahedra, edges with six equivalent Mn(3)U6Mn2Al4 cuboctahedra, faces with two equivalent Mn(3)U6Mn2Al4 cuboctahedra, faces with three equivalent Mn(1)U6Mn4Al2 cuboctahedra, faces with three equivalent Mn(2)U6Mn4Al2 cuboctahedra, faces with three equivalent Al(1)U6Mn2Al4 cuboctahedra, faces with three equivalent Al(2)U6Mn2Al4 cuboctahedra, faces with three equivalent Al(3)U6Mn2Al4 cuboctahedra, and faces with three equivalent Al(4)U6Mn6 cuboctahedra. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent U(2), four equivalent U(1), two equivalent Mn(3), two equivalent Al(2), and two equivalent Al(3) atoms to form AlU6Mn2Al4 cuboctahedra that share corners with two equivalent Al(4)U6Mn6 cuboctahedra, corners with four equivalent Mn(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(1)U6Mn4Al2 cuboctahedra, corners with four equivalent Mn(2)U6Mn4Al2 cuboctahedra, corners with four equivalent Al(1)U6Mn2Al4 cuboctahedra, edges with two equivalent Al(1)U6Mn2Al4 cuboctahedra, edges with four equivalent Al(4)U6Mn6 cuboctahedra, faces with two equivalent Mn(1)U6Mn4Al2 cuboctahedra, faces with two equivalent Mn(2)U6Mn4Al2 cuboctahedra, faces with four equivalent Al(2)U6Mn2Al4 cuboctahedra, faces with four equivalent Al(3)U6Mn2Al4 cuboctahedra, and faces with six equivalent Mn(3)U6Mn2Al4 cuboctahedra. In the second Al site, Al(2) is bonded to two equivalent U(2), four equivalent U(1), two equivalent Mn(3), two equivalent Al(1), and two equivalent Al(3) atoms to form AlU6Mn2Al4 cuboctahedra that share corners with two equivalent Mn(1)U6Mn4Al2 cuboctahedra, corners with four equivalent Mn(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(2)U6Mn4Al2 cuboctahedra, corners with four equivalent Al(2)U6Mn2Al4 cuboctahedra, corners with four equivalent Al(4)U6Mn6 cuboctahedra, edges with two equivalent Al(2)U6Mn2Al4 cuboctahedra, edges with four equivalent Mn(1)U6Mn4Al2 cuboctahedra, faces with two equivalent Mn(2)U6Mn4Al2 cuboctahedra, faces with two equivalent Al(4)U6Mn6 cuboctahedra, faces with four equivalent Al(1)U6Mn2Al4 cuboctahedra, faces with four equivalent Al(3)U6Mn2Al4 cuboctahedra, and faces with six equivalent Mn(3)U6Mn2Al4 cuboctahedra. In the third Al site, Al(3) is bonded to two equivalent U(2), four equivalent U(1), two equivalent Mn(3), two equivalent Al(1), and two equivalent Al(2) atoms to form AlU6Mn2Al4 cuboctahedra that share corners with two equivalent Mn(2)U6Mn4Al2 cuboctahedra, corners with four equivalent Mn(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(1)U6Mn4Al2 cuboctahedra, corners with four equivalent Al(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Al(4)U6Mn6 cuboctahedra, edges with two equivalent Al(3)U6Mn2Al4 cuboctahedra, edges with four equivalent Mn(2)U6Mn4Al2 cuboctahedra, faces with two equivalent Mn(1)U6Mn4Al2 cuboctahedra, faces with two equivalent Al(4)U6Mn6 cuboctahedra, faces with four equivalent Al(1)U6Mn2Al4 cuboctahedra, faces with four equivalent Al(2)U6Mn2Al4 cuboctahedra, and faces with six equivalent Mn(3)U6Mn2Al4 cuboctahedra. In the fourth Al site, Al(4) is bonded to two equivalent U(1), four equivalent U(2), two equivalent Mn(1), two equivalent Mn(2), and two equivalent Mn(3) atoms to form AlU6Mn6 cuboctahedra that share corners with two equivalent Al(1)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Al(2)U6Mn2Al4 cuboctahedra, corners with four equivalent Al(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Al(4)U6Mn6 cuboctahedra, edges with two equivalent Al(4)U6Mn6 cuboctahedra, edges with four equivalent Al(1)U6Mn2Al4 cuboctahedra, faces with two equivalent Al(2)U6Mn2Al4 cuboctahedra, faces with two equivalent Al(3)U6Mn2Al4 cuboctahedra, faces with four equivalent Mn(1)U6Mn4Al2 cuboctahedra, faces with four equivalent Mn(2)U6Mn4Al2 cuboctahedra, and faces with six equivalent Mn(3)U6Mn2Al4 cuboctahedra. is represented by the CIF card [CIF]
data_UMnAl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.203
_cell_length_b   5.102
_cell_length_c   8.745
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.727
_symmetry_Int_Tables_number   1
_cell_volume   199.573
_cell_formula_units_Z   4
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
  U  U0  1  0.653  0.304  0.529  1.0
  U  U1  1  0.342  0.686  0.437  1.0
  U  U2  1  0.342  0.686  0.063  1.0
  U  U3  1  0.653  0.304  0.971  1.0
  Mn  Mn4  1  0.845  0.187  0.250  1.0
  Mn  Mn5  1  0.340  0.187  0.250  1.0
  Mn  Mn6  1  0.998  0.996  0.501  1.0
  Mn  Mn7  1  0.998  0.996  0.999  1.0
  Al  Al8  1  0.161  0.321  0.750  1.0
  Al  Al9  1  0.158  0.823  0.750  1.0
  Al  Al10  1  0.666  0.822  0.750  1.0
  Al  Al11  1  0.844  0.690  0.250  1.0
[/CIF]
.
The crystal structure described by UMnAl is Frank-Kasper $\mu$ Phase-derived structured and crystallizes in the monoclinic Pm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 15-coordinate geometry to three equivalent U(2), one Mn(1), one Mn(2), three equivalent Mn(3), one Al(4), two equivalent Al(1), two equivalent Al(2), and two equivalent Al(3) atoms. In the second U site, U(2) is bonded in a 16-coordinate geometry to one U(2), three equivalent U(1), two equivalent Mn(1), two equivalent Mn(2), three equivalent Mn(3), one Al(1), one Al(2), one Al(3), and two equivalent Al(4) atoms. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent U(1), four equivalent U(2), two equivalent Mn(2), two equivalent Mn(3), and two equivalent Al(4) atoms to form MnU6Mn4Al2 cuboctahedra that share corners with two equivalent Al(2)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(1)U6Mn4Al2 cuboctahedra, corners with four equivalent Al(1)U6Mn2Al4 cuboctahedra, corners with four equivalent Al(3)U6Mn2Al4 cuboctahedra, edges with two equivalent Mn(1)U6Mn4Al2 cuboctahedra, edges with four equivalent Al(2)U6Mn2Al4 cuboctahedra, faces with two equivalent Al(1)U6Mn2Al4 cuboctahedra, faces with two equivalent Al(3)U6Mn2Al4 cuboctahedra, faces with four equivalent Mn(2)U6Mn4Al2 cuboctahedra, faces with four equivalent Al(4)U6Mn6 cuboctahedra, and faces with six equivalent Mn(3)U6Mn2Al4 cuboctahedra. In the second Mn site, Mn(2) is bonded to two equivalent U(1), four equivalent U(2), two equivalent Mn(1), two equivalent Mn(3), and two equivalent Al(4) atoms to form MnU6Mn4Al2 cuboctahedra that share corners with two equivalent Al(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(2)U6Mn4Al2 cuboctahedra, corners with four equivalent Al(1)U6Mn2Al4 cuboctahedra, corners with four equivalent Al(2)U6Mn2Al4 cuboctahedra, edges with two equivalent Mn(2)U6Mn4Al2 cuboctahedra, edges with four equivalent Al(3)U6Mn2Al4 cuboctahedra, faces with two equivalent Al(1)U6Mn2Al4 cuboctahedra, faces with two equivalent Al(2)U6Mn2Al4 cuboctahedra, faces with four equivalent Mn(1)U6Mn4Al2 cuboctahedra, faces with four equivalent Al(4)U6Mn6 cuboctahedra, and faces with six equivalent Mn(3)U6Mn2Al4 cuboctahedra. In the third Mn site, Mn(3) is bonded to three equivalent U(1), three equivalent U(2), one Mn(1), one Mn(2), one Al(1), one Al(2), one Al(3), and one Al(4) atom to form MnU6Mn2Al4 cuboctahedra that share corners with two equivalent Mn(1)U6Mn4Al2 cuboctahedra, corners with two equivalent Mn(2)U6Mn4Al2 cuboctahedra, corners with two equivalent Al(1)U6Mn2Al4 cuboctahedra, corners with two equivalent Al(2)U6Mn2Al4 cuboctahedra, corners with two equivalent Al(3)U6Mn2Al4 cuboctahedra, corners with two equivalent Al(4)U6Mn6 cuboctahedra, edges with six equivalent Mn(3)U6Mn2Al4 cuboctahedra, faces with two equivalent Mn(3)U6Mn2Al4 cuboctahedra, faces with three equivalent Mn(1)U6Mn4Al2 cuboctahedra, faces with three equivalent Mn(2)U6Mn4Al2 cuboctahedra, faces with three equivalent Al(1)U6Mn2Al4 cuboctahedra, faces with three equivalent Al(2)U6Mn2Al4 cuboctahedra, faces with three equivalent Al(3)U6Mn2Al4 cuboctahedra, and faces with three equivalent Al(4)U6Mn6 cuboctahedra. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent U(2), four equivalent U(1), two equivalent Mn(3), two equivalent Al(2), and two equivalent Al(3) atoms to form AlU6Mn2Al4 cuboctahedra that share corners with two equivalent Al(4)U6Mn6 cuboctahedra, corners with four equivalent Mn(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(1)U6Mn4Al2 cuboctahedra, corners with four equivalent Mn(2)U6Mn4Al2 cuboctahedra, corners with four equivalent Al(1)U6Mn2Al4 cuboctahedra, edges with two equivalent Al(1)U6Mn2Al4 cuboctahedra, edges with four equivalent Al(4)U6Mn6 cuboctahedra, faces with two equivalent Mn(1)U6Mn4Al2 cuboctahedra, faces with two equivalent Mn(2)U6Mn4Al2 cuboctahedra, faces with four equivalent Al(2)U6Mn2Al4 cuboctahedra, faces with four equivalent Al(3)U6Mn2Al4 cuboctahedra, and faces with six equivalent Mn(3)U6Mn2Al4 cuboctahedra. In the second Al site, Al(2) is bonded to two equivalent U(2), four equivalent U(1), two equivalent Mn(3), two equivalent Al(1), and two equivalent Al(3) atoms to form AlU6Mn2Al4 cuboctahedra that share corners with two equivalent Mn(1)U6Mn4Al2 cuboctahedra, corners with four equivalent Mn(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(2)U6Mn4Al2 cuboctahedra, corners with four equivalent Al(2)U6Mn2Al4 cuboctahedra, corners with four equivalent Al(4)U6Mn6 cuboctahedra, edges with two equivalent Al(2)U6Mn2Al4 cuboctahedra, edges with four equivalent Mn(1)U6Mn4Al2 cuboctahedra, faces with two equivalent Mn(2)U6Mn4Al2 cuboctahedra, faces with two equivalent Al(4)U6Mn6 cuboctahedra, faces with four equivalent Al(1)U6Mn2Al4 cuboctahedra, faces with four equivalent Al(3)U6Mn2Al4 cuboctahedra, and faces with six equivalent Mn(3)U6Mn2Al4 cuboctahedra. In the third Al site, Al(3) is bonded to two equivalent U(2), four equivalent U(1), two equivalent Mn(3), two equivalent Al(1), and two equivalent Al(2) atoms to form AlU6Mn2Al4 cuboctahedra that share corners with two equivalent Mn(2)U6Mn4Al2 cuboctahedra, corners with four equivalent Mn(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(1)U6Mn4Al2 cuboctahedra, corners with four equivalent Al(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Al(4)U6Mn6 cuboctahedra, edges with two equivalent Al(3)U6Mn2Al4 cuboctahedra, edges with four equivalent Mn(2)U6Mn4Al2 cuboctahedra, faces with two equivalent Mn(1)U6Mn4Al2 cuboctahedra, faces with two equivalent Al(4)U6Mn6 cuboctahedra, faces with four equivalent Al(1)U6Mn2Al4 cuboctahedra, faces with four equivalent Al(2)U6Mn2Al4 cuboctahedra, and faces with six equivalent Mn(3)U6Mn2Al4 cuboctahedra. In the fourth Al site, Al(4) is bonded to two equivalent U(1), four equivalent U(2), two equivalent Mn(1), two equivalent Mn(2), and two equivalent Mn(3) atoms to form AlU6Mn6 cuboctahedra that share corners with two equivalent Al(1)U6Mn2Al4 cuboctahedra, corners with four equivalent Mn(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Al(2)U6Mn2Al4 cuboctahedra, corners with four equivalent Al(3)U6Mn2Al4 cuboctahedra, corners with four equivalent Al(4)U6Mn6 cuboctahedra, edges with two equivalent Al(4)U6Mn6 cuboctahedra, edges with four equivalent Al(1)U6Mn2Al4 cuboctahedra, faces with two equivalent Al(2)U6Mn2Al4 cuboctahedra, faces with two equivalent Al(3)U6Mn2Al4 cuboctahedra, faces with four equivalent Mn(1)U6Mn4Al2 cuboctahedra, faces with four equivalent Mn(2)U6Mn4Al2 cuboctahedra, and faces with six equivalent Mn(3)U6Mn2Al4 cuboctahedra. is represented by the CIF card [CIF]
data_UMnAl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.203
_cell_length_b   5.102
_cell_length_c   8.745
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.727
_symmetry_Int_Tables_number   1
_cell_volume   199.573
_cell_formula_units_Z   4
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
  U  U0  1  0.653  0.304  0.529  1.0
  U  U1  1  0.342  0.686  0.437  1.0
  U  U2  1  0.342  0.686  0.063  1.0
  U  U3  1  0.653  0.304  0.971  1.0
  Mn  Mn4  1  0.845  0.187  0.250  1.0
  Mn  Mn5  1  0.340  0.187  0.250  1.0
  Mn  Mn6  1  0.998  0.996  0.501  1.0
  Mn  Mn7  1  0.998  0.996  0.999  1.0
  Al  Al8  1  0.161  0.321  0.750  1.0
  Al  Al9  1  0.158  0.823  0.750  1.0
  Al  Al10  1  0.666  0.822  0.750  1.0
  Al  Al11  1  0.844  0.690  0.250  1.0
[/CIF]
.