Phonon Density of States (PDOS) at Gamma Point

[RaquelYR]

Hello everyone!

I'm trying to replicate phonon density of states (PHDOS) diagrams for some solids using Quantum Espresso. The usual way I do it is the following one:

1. scf calculation at minima (pw.x)
2. Calculation of dynamical matrix in reciprocal space with nq=1 or 2 (ph.x)
3. Calculation of interatomic force constants in real space (q2r.c)
4. Calculation of phonon frequency (matdyn.x)

The frequencies I obtained differ with the ones of the example. The only significant difference that I find is that they perform the calculation at Gamma Point. I have tried to carry out my procedure at gamma point but it seems to be incompatible.

Does any one know how can I get the phonon density of states at gamma point?

Thank you in advance!

 

[TeethWhitener]

It makes no sense to calculate a density of states at the gamma point. The gamma point is only a single point in the Brillouin zone, whereas a density of states gives you the number of states across the entire Brillouin zone with energies between $E$ and $E+dE$. Regardless, here’s a tutorial for getting a phonon DOS specifically (this person has a whole series of tutorials for Quantum Espresso that are quite good):