I’m writing this post because I had a lot of people asking me about this.
Calculating the bandstructure is a straight-forward job in Quantum Espresso, and then finding the band-gap is trivial.
But it takes a lot of time, and if you want to do some quick calculations and see the effect of changing some parameter on the band-gap, then you wouldn’t want to spend so much time.
So, people asked me if it was possible to get the band-gap value from SCF calculation itself, as it is relatively faster.
The answer is YES!
In your input file, just set occupations to ‘fixed’, that is no Gaussian Smearing. And provide a value for “nbnd” parameter.
If you don’t provide the “nbnd” parameter, then only the highest occupied level is printed.
If you provide Gaussian Smearing then Fermi Energy is given instead.
You can also check out the video tutorial:
Example input:
Output:
References:
http://www.quantum-espresso.org/faq/self-consistency/
http://qe-forge.org/pipermail/pw_forum/2016-August/110618.html
http://qe-forge.org/pipermail/pw_forum/2009-March/086756.html
Get Article as PDF
hi manas,
In my case even after providing nbnd parameter I am getting only the highest value. Please tell me how will I run this calculation succesfully
hi manas,
In my case even after providing nbnd parameter I am getting only the highest value.
Please , i would appreciate if you could send me a gnuplot or any scripts on how to plot band structure and DOS together on the same graph side by side
Hey
Thank you so much. actually your videos are my inspiration and i learnt much in DFT from the videos you uploaded. Here I have one quick question. Can we model like ultra-thin atomic layer of ferromagnet in contact with rare-earth metals. Can we model thin bilayer films?
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