<div dir="ltr"><div>Hello!</div><div>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.</div><div>I use the startingpot and startingwfc options to use the first scf information for <span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-">speed up the convergence.</span></span></div><div><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"><br></span></span></div><div><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-">When i use both, the density is the density for the neutral system, and the guess wfc are the neutral system wfc set.</span></span></div><div><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"><br></span></span></div><div><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-">When i use only the startingwfc, the density is a superposition of free atoms guess, and the wfc <span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-">are the neutral system wfc set.</span></span></span></span></div><div><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"><br></span></span></span></span></div><div><div><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-">When i use only the startingpot, <span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-">the density is the density for the neutral system, and the wfc are a "random+atomic" set.</span></span></span></span></div><div><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"><br></span></span></span></span></div><div><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-">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).</span></span></span></span></div><div><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-">How can i do this? Is this a good idea?</span></span></span></span></div><div><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"><br></span></span></span></span></div><div><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-">I propound this, because the 3 cases for starting commands are not the best approach to charged systems.</span></span></span></span></div><div><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"><br></span></span></span></span></div><div><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-">Regards<br></span></span></span></span></div><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"><span class="gmail-tlid-translation gmail-translation" lang="en"><span title="" class="gmail-"></span></span></span></span></div></div>