Hi! This is Jess from QuantumWise. Today I would like to show you how Virtual NanoLab can be used as an
interface for QuantumEspresso. So let’s consider a silicon crystal. Here in
in Virtual NanoLab, I will first built the silicon crystal It is available in the database.
it’s really simple. I add silicon to the Stash. Now I can export by right-clicking I can export a Quantum Espresso input file. So I choose it and give it a the filename. I will call it “scf.in”. Now it’s very important that the input file, that was just exported, is a template input file. So it will need some editing before it makes sense to do some calculations with it. I’m going to use terminal for that. I close the Builder and open up my terminal. My input file is right here and I will open it and edit it slightly. I would like Espresso output go to this silicon directory. I would like to use a local pseudopotential. Let’s see. A higher cutoff energy for the
electron density. I would like to use PBE. Since silicon is a semiconductor I will
not need these 3 lines. However I would like you to set explicitly 10 bands for the calculation I will also need to set the K-point density so let’s see 8 by
8 k-points and finally I need to instruct Espresso to use the correct
pseudopotential. I will download a pseudopotential
from the website right here. Do a bit of filtering. I want it to be PPE ultra soft and scalar relativistic. Let’s see what’s available for silicon. We simply download this one. Save it. And back in the directory the pseudopotential is right here. I just need to put that name into the
input file. Like that. Now done, ready to start the calculation. This one should look like that. and sent the output to scf.out. Now it’s very important to send the output to a .out file. otherwise Virtual NanoLab will not be able to interpret the output. This time it worked of course. We see the output popping up at the Lab Floor right here. We have the silicon crystal looking
as it should. We have a totally energy report from the calculation. So these are the energy components and we have the total energy in electron volts. We also have the electron density right here and we can make an isosurface plot
of the self-consistent electron density in
silicon. This is what it looks like. Let’s try to see a few more ISO values. We can tune it right here and the plot changes. There are many other things you can do with the QuantumEspresso in VNL (Virtual NanoLab) This was just a slight overview. Thank you very much!