Emission spectra of materials

[rishikanta_m]

Hi

I am curious to know if it is possible to get emission spectra either by direct calculations or by using some of the optical properties from VASP. Please guide.

[henrique_miranda]

You can for example compute the optical absorption spectrum in the independent particle approximation using the LOPTICS tag:
wiki/index.php/LOPTICS

If you want to include excitonic effects you might want to do a BSE calculation:
wiki/index.php/Bethe-Salpeter-equations_calculations

What exactly do you mean by optical emission spectra?
Luminescence?
Simulating a LED?

[rishikanta_m]

Yes, correct, photoluminesce, mainly for lasing applications.

I have some knowledge of the optical properties of VASP. Although optical absorption is somehow related to the emission, I would like to get the exact emission spectra?

[henrique_miranda]

Currently, there is no out-of-the-box method to compute luminescence spectra from VASP.
You might want to look for literature related to the delta-SCF method and whether that can help for the application you have in mind.
Be aware that this requires very specific considerations for the system and excitations you want to simulate.