# Documentation of the inputs of the aiida-wannier90 plugin¶

We describe here with an example the format of the inputs expected by the Wannier90 plugin.

You can check also the folder examples/example01 in the source repository for an actual script that you can run.

## use_parameters¶

Pass a ParameterData with the input keys for Wannier90. An example:

parameter = ParameterData(dict={'bands_plot':False,
'num_iter': 12,
'guiding_centres': True,
'num_wann': 4,
'wannier_plot':True,
'wannier_plot_list':[1]
})


## use_structure¶

Pass a StructureData for the input structure.

## use_kpoints¶

Pass a k-points mesh to be used as size of the Monkhorst-Pack grid of the DFT calculation. Example:

kpoints = KpointsData()
kpoints.set_kpoints_mesh([2, 2, 2])


## use_kpoint_path¶

Optional, pass a ParameterData to specify the path to follow for the interpolated band structure. The dictionary should only have two entries:

• path: a list of length-2 lists, with the labels for the extremes of each path
• point_coords: a dictionary that for each label gives the coordinates (in fractional coordinates with respect to the primitive reciprocal lattice vectors).

This information can, e.g., be easily obtained from the output of seekpath.

Example:

{
'path': [
['GAMMA', 'X'],
['X', 'U'],
['K', 'GAMMA'],
['GAMMA', 'L'],
['L', 'W'],
['W', 'X']
],
'point_coords':
{
'GAMMA': [0.0, 0.0, 0.0],
'K': [0.375, 0.375, 0.75],
'L': [0.5, 0.5, 0.5],
'U': [0.625, 0.25, 0.625],
'W': [0.5, 0.25, 0.75],
'W_2': [0.75, 0.25, 0.5],
'X': [0.5, 0.0, 0.5]
}
}


## use_local_input_folder or use_remote_input_folder¶

Pass the parent folder with the .amn, .mmn, … files. It can either be a FolderData (for use_local_input_folder) containing the files, or a RemoteData with the output of e.g. a quantumespresso.pw2wannier90 calculation. If you pass both, files will be taken from both, with precedence from the local folder.

## use_projections¶

To pass the information on the mesh to use. We provide a helper function to prepare the proper OrbitalData class, called generate_projections. For instance, the following puts a projection at the given Cartesian coordinate (1,2,0.5), with given properties (radial, angular momentum, …):

from aiida_wannier90.orbitals import generate_projections
projections = generate_projections(dict(position_cart=(1,2,0.5),
ang_mtm_l=2,
ang_mtm_mr=5, spin=None,
#zona=1.1,
zaxis=(0,1,0),xaxis=(0,0,1), spin_axis=None),structure=structure)


As a second option, you can pass directly a List object, with a list of strings that will be put in the input file of Wannier90. Note, however, that this format is discouraged: better to pass the OrbitalData object, that contains ‘parsed’ information and is easier to query, and set random_projections = True in the input ‘settings’ ParameterData node. For instance:

from aiida.orm.data.base import List
projections = List()
projections.extend(['As:s','As:p'])
projections.extend(['random','As:s'])


If really needed (but strongly discouraged for the reason explained above), if you have a OrbitalData as in the first example, you can convert to an explicit list as in the second example with the following snippet (the optional random_projections additional flag adds a random string in the flag, to tell Wannier90 that missing projections should be selected randomly):

from aiida_wannier90.io._write_win import _format_all_projections
projections_list = List()
projections_list.extend(_format_all_projections(projections, random_projections=True))
projections = projections_list


## use_settings¶

An optional ParameterData with additional settings. The possible values are:

• seedname: pass a string if the seedname is not the default aiida (e.g. if you run the calculation manually and the .mmn, .amn, … files use a different seedname
• random_projections: if True, adds the string random to the projections, needed in case you are specifying less projections than Wannier functions
• postproc_setup: if True, run just with the -pp options (preprocessing, to generate the .nnkp file).
• retrieve_hoppings: if True, retrieve also hopping files needed to obtain the Hamiltonian (<seedname>_hr.dat, <seedname>_centres.xyz, <seedname>_wsvec.dat).