topoPhonon package is a python package that allows users to phononic calculate topological properties, by building phonon tight-binding model.
- Build tight-binding models from user's input, FORCE_CONSTANTS files or Phonopy API. The last method is much faster, but need to import Phonopy package and manually create phonopy.harmonic.dynamical_matrix.DynamicalMatrix object.
- Calculate berry phase, berry curvature, wannier charge center evolution around Weyl points from tight-binding model.
- Build slab/ribbon models for surface/edge.
- Plot 3d band surfaces.
pip install topophonon
Use one line of code to build tight-binding model:
model = read_from_files(path)
where the path should contain POSCAR, SPOSCAR and FORCE_CONSTANTS files.
From the model just built, build a slab model with multi
layers along fin_dir
:
model_2d = model.cut_piece(multi, fin_dir)
model_2d = model_2d.atom_projected_band(q_path, node_names)
Create a Topology object:
tp = Topology(model)
Plot the energy surfaces of band1
and band2
and find the degenerate points on z=0 plane:
model.plot_3d_band([band1, band2], center, xy_range)
Then plot wannier charge center evolution around center
for band_indices
:
tp.wcc_evol_sphere(band_indices, center)
and the berry curvature distribution on kz
plane, where dirc
= 0, 1, 2, respectively:
tp.berry_curvature_proj(band_indices, dirc, kz)