[QE-users] Density Guess and wfc guess

[Lucas Nicolás Lodeiro Moraga]

Hello!
I'm working with QE 5.3 version. I want to simulate a charged slab, for
that, i am doing a neutral scf calculation first, and in the second step, a
scf calculation for the charged slab.
I use the startingpot and startingwfc options to use the first scf
information for speed up the convergence.

When i use both, the density is the density for the neutral system, and the
guess wfc are the neutral system wfc set.

When i use only the startingwfc, the density is a superposition of free
atoms guess, and the wfc are the neutral system wfc set.

When i use only the startingpot, the density is the density for the neutral
system, and the wfc are a "random+atomic" set.

This is the question. From my logic, the best speed up is when use the
neutral system wfc set, and the density is constructed with this wfcs, but
using the correct number of electrons to the charged system, then this
density is the density for the freezed neutral system plus the
substraction/addition electrons to charge the system (the orbital density).
How can i do this? Is this a good idea?

I propound this, because the 3 cases for starting commands are not the best
approach to charged systems.

Regards
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