Calculate the band structure of a crystal¶
In this tutorial, you will learn how to calculate the band structure of silicon by using the extended Hückel method.
Start VNL and create a new project¶
Open VNL and create a new project by clicking Create New. Give the project a Title (here: “Silicon_band_structure”), select the folder where data will be stored, then click OK and Open to start the project.
Import the Silicon structure from the Database and send it to the Scripter¶
Set up the calculation and analyse the band structure¶
Change the default name of the NetCDF file in the Global IO options: Type in
- Set the calculator to “Extended Hückel” (or leave it at DFT if you so prefer), and specify a k-point sampling of nA = nB = nC = 13.
- If you use the Extended Hückel, you must also change the basis set to Cerda.Silicon to get a proper description of the band gap.
- Click OK to save the changes.
Now open the Bandstructure block. We will not change anything, but you can see how the path in the face-centered cubic Brillouin zone between the symmetry points G, X, W, L, G, K, X, U, W, K, L, is set up. Click OK.
If you are interested in inspecting the actual Python script, you can now send the scipt to the Editor: Use the button or simply drag and drop it onto . Note that this will minimize the Script Generator window.
Save the script in the window that appears.
When the script has finished (it should only take a few seconds), go back to the main VNL window, and click the tab () next to your NetCDF file,
Si_band_structure.nc, to see the objects contained in it.
Select the Bandstructure object and plot it with the Bandstructure Analyzer in the right-hand plugins panel.