You've activated the Wannier functions in-app guide.
In this guide, you will learn how to use the app to compute and visualize Wannier functions for Gallium arsenide (GaAs).
Pre-requisite: This guide assumes that you already followed the Relaxation and electronic structure → Basic tutorial guide, or that you are already familiar with the app.
Click on Step 1: Select structure and follow the instructions to proceed.

Tasks

  1. Select the "Gallium arsenide" example structure
  2. Click Confirm to proceed

Tasks

  1. Select Structure as is - we skip optimizing the structure for this example
  2. Open Step 2.1 for further instructions

Tasks

  1. Select Wannier functions
  2. Go to Step 2.2 for further instructions

Tasks

  1. Select the Fast protocol
  2. See further instructions in the Wannier functions panel
This section customizes the Wannier function calculation.
"Retrieve Hamiltonian '_tb.dat' file" checkbox allows to save the tight-binding Hamiltonian file produced by Wannier90.
Other input/output files ('amn', 'mmn', 'eig', 'chk', 'spn') can also be saved for reuse by ticking the corresponding checkbox.
You can learn more about the "Compute Fermi surface" option in the corresponding in-app guide.
"Automated Wannierization algorithm" and "Frozen states" dropdowns describe the algorithm and parameters for the automated Wannierization process.

Tasks

  1. Tick the Compute real-space Wannier functions checkbox
  2. Click Confirm to proceed

Tasks

  1. Keep the default resources (1 node/1 CPU per code)
  2. (Optional) customize the workflow label and description
  3. Click Submit to submit the workflow to the AiiDA engine

Tasks

  1. Switch to the Results panel for further instructions
  2. Click on the Wannier functions tab
  3. Click the Load results button once it becomes available
Here we can compare the electronic band structures computed from DFT and Wannier interpolation. DFT bands are shown in solid black lines, while Wannier-interpolated bands are shown in dashed red lines.
For Fast protocol, the Wannier-interpolated band structure is not expected to perfectly match the DFT one, but it should still capture the main features of the band structure.
The table below summarizes the details of the Wannierization procedure, including the number of Wannier functions, the spread values and the average distance between Wannier and DFT bands as defined in J. Qiao et al. npj. Comput. Mater. 9, 208 (2023).
The list of Wannier functions with their center positions and spreads is shown in the table below.
Click on a table row to visualize the corresponding Wannier function in real space (shown below).
In the following section you can download desired files, such as the tight-binding Hamiltonian file or real-space Wannier function data.