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k-Subgroupsmag: Magnetic subgroups compatible with some given propagation vector(s) or a supercell.


k-Subgroupsmag
The program k-Subgroupsmag provides the possible magnetic subgroups of the space group of a paramagnetic phase (gray group) which are possible for a magnetic ordering having a known propagation vector. The program provides the set of magnetic subgroups or a graph showing the subgroup-tree (grouped into conjugacy classes). In both cases, more information about the classes or subgroups can be obtained.

Other alternatives for the input of the program:

  • An alternative parent (non gray) magnetic group can be chosen.
  • Instead of the whole set of subgroups, the output can be limited to subgroups having a chosen common subgroup of lowest symmetry, common point group of lowest symmetry, or groups which belong to a specific crystal class.
  • Further restrictions on the subgroup list/graph considering physical properties can be used: it is possible to ask for only centrosymmetric or non-centrosymmetri groups, polar or non-polar groups.
  • More than one propagation wave-vector can be chosen.
  • The whole (or partial) stars of vectors can be introduced.
  • Non magnetic modulation wave-vectors can be also introduced.
  • Instead of propagation wave-vectors, a supercell can be given. In this case, all subgroups with their lattice defined by the supercell are given, including the gray ones.
  • It is possible to ask for a list/graph of subgroups compatible with the intermediate cells between the unit cell of the parent space group and the supercell determined by the given wave vector(s) (or the given supercell when the previous option is used).
  • The output can be further refined introducing the Wyckoff positions of the magnetic atoms (and the positions of the non-magnetic atoms for non-magnetic distortions) and/or a set of irreducible representations.

    • Tutorial: download

    You can find examples of application of this program in:

    Perez-Mato, JM; Gallego, SV; Elcoro, L; Tasci, E and Aroyo, MI
    J. of Phys.: Condens Matter (2016), 28:28601


    and in:

    J.M. Perez-Mato, S.V. Gallego, E.S. Tasci, L. Elcoro, G. de la Flor, and M.I. Aroyo
    Annu. Rev. Mater. Res. (2015), 45:13.1-13.32
    See the Help for details.
    Enter the serial number of the space group of the parent paramagnetic phase:
    Choose an alternative magnetic group
    Alternatively give the operations of the space group in a non-standard setting

    Introduce the magnetic wave vector(s)
    (Give the components of the wave vectors in a fractional form, n/m)
    k1x    k1y    k1z 
    Choose the whole star of the propagation vector

    Include the subgroups compatible with intermediate cells.
    (It is not applied when only the maximal subgroups are calculated)

    Optional: refine further the subgroups of the output giving the Wyckoff positions of the atoms
    Give the Wyckoff positions

    Optional: Show only subgroups that can be the result of a Landau-type transition (single irrep order parameter).

    Optional: refine further the subgroups of the output giving a set of irreps
    Choose the irreps

    Optional: possible limitations of the subgroup list
    (Check only one option on the left and the specific value on the right)
    Lowest space group to consider
    Lowest point group to consider
    Lowest crystal system to consider
    Only maximal subgroups

    Optional: further limitations considering physical properties of the point groups
  • Only centrosymmetric / non-centrosymmetric groups
    		•
  • Only polar / non-polar groups
    		•

    List of subgroups Graph of subgroups

    k-Subgroupsmag
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