bandu 1.1.0

The BandU program constructs a rank ordered series of crystal orbitals using principal component analysis. These principal orbital components can then be projected on the Fermi surface and visualized

BandU

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BandU OVERVIEW

A package that performs a principal component inspired analysis on the Bloch wavefunctions of periodic material to provide a real space visualization of the states that significantly contribute to the Fermi surface.

These real space functions can then be projected onto the Fermi surface to provide a clear visual for where a nesting vector may combine two points in reciprocal space.

This package is designed to be very straightforward in its use, offering Fermi surface and BandU function visualizations in as little as 5 lines of Python script. This package can also be used to just visual the Fermi surface, without BandU projections, if provided with the necessary k-point and eigenvalue data.

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INSTALLATION INSTRUCTIONS

1. Inside that directory type on the command line
   "git clone https://github.com/pcross0405/BandU.git"

2. Type "cd BandU"

3. Make sure you have python's build tool up to date with
   "python3 -m pip install --upgrade build"

4. Once up to date type
   "python3 -m build"

5. This should create a "dist" directory with a .whl file inside

6. On the command line type
   "pip install dist/*.whl"

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DEPENDENCIES

REQUIRED FOR VISUALIZING FERMI SURFACE

• pyvista

• numpy

REQUIRED FOR CUSTOM COLORS

• matplotlib

WAVEFUNCTIONS THAT CAN BE READ DIRECTLY

Currently only reading directly from ABINIT 7 and 10 wavefunctions is supported. Reading eigenvalues from other DFT packages will come in future updates.

• ABINIT

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REPORTING ISSUES

Please report any issues here

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TUTORIAL

An example script that can run the different functions of the BandU program is given below.

from bandu.bandu import BandU
from bandu.abinit_reader import AbinitWFK
from bandu.isosurface_class import Isosurface
from bandu.plotter import Plotter
from bandu.colors import Colors

root_name = 'your file root name here' # root_name of WFK files and of XSF files
xsf_number = 1 # XSF file number to be read in
energy_level = 0.000 # Energy relative to the Fermi energy to be sampled
width = 0.0005 # Search half the the width above and below the specified energy level
wfk_path = f'path\to\WFK\file\{root_name}_o_WFK'
xsf_path = f'path\to\XSF\file\{root_name}_bandu_{xsf_number}'
bandu_name = f'{root_name}_bandu'

def main(
        Band_U:bool, Iso_Surf:bool, Load_Surf:bool
)->None:
    if Band_U: # create BandU principal orbital components
        wfk_gen = AbinitWFK(wfk_path).ReadWFK(
            energy_level = energy_level,
            width=width
         )
        wfk = BandU(
            wfks = wfk_gen,
            energy_level = energy_level,
            width = width,
            sym = True
         )
        wfk.ToXSF(
            xsf_name = bandu_name,
            nums = [1,10]
         )
    elif Iso_Surf: # construct energy isosurfaces and plot them
        contours = Isosurface(
            wfk_name = wfk_path,
            energy_level = energy_level,
            width = width
        )
        contours.Contour() # make contours
        plot = Plotter(
            isosurface = contours,
            save_file=f'{root_name}_bandu_{xsf_number}_fermi_surf.pkl'
         ) # create plotter object
        overlap_vals = plot.SurfaceColor(
            wfk_path=wfk_path,
            xsf_path=xsf_path,
        ) # compute overlap between principal orbital component and states in Brillouin Zone
        plot.Plot(
            surface_vals = overlap_vals,
            colormap = Colors().blues,
        ) # plot contours
    elif Load_Surf:
        Plotter().Load(
            save_path='{root_name}_bandu_{xsf_number}_fermi_surf.pkl',
        )
if __name__ == '__main__':
    main(
        Band_U = False,
        Iso_Surf = False,
        Load_Surf = False,
    )