<div dir="ltr"><div><div><div>Dear all,<br><br></div>I did some calculations for induced magnetism in <span style class="">graphene</span> due to single vacancy (sometimes <span style class="">reffered</span> as V1(5-9))<br>
using <span style class="">USPP</span> (<a class="" target="_blank" href="http://www.quantum-espresso.org/wp-content/uploads/upf_files/C.pbe-van_ak.UPF">C.<span style class="">pbe</span>-van_<span style class="">ak</span>.<span style class="">UPF</span></a>; <span style class="">ecutwfc</span>=30, <span style class="">ecutrho</span>=160) and <span style class="">NCPP</span> (<a class="" target="_blank" href="http://www.quantum-espresso.org/wp-content/uploads/upf_files/C.pbe-mt_fhi.UPF">C.<span style class="">pbe</span>-mt_<span style class="">fhi</span>.<span style class="">UPF</span></a>, <span style class="">ecutwfc</span>=35, <span style class="">ecutrho</span>=140).<br>
Calculations of relaxed structure give magnetic moment in the <span style class="">supercell</span> of about 0.65 \mu_B in both the PP cases.<br>However, I did calculations of the same structure using full-potential <span style class="">LAPW</span> code FLEUR where the magnetic moment <br>
(spin_up - spin_down) drops to value of 0.12256. There are also studies where similar structures have been studied <br>with SIESTA code:<br></div><div>depending of <span style class="">supercell</span> size from 1.1 to 1.5 \mu_B [<span style class="">Yazyev</span> <span style class="">et</span> <span style class="">al</span>, Phys Rev B 75, 125408]<br>
<span style class="">Normconserving</span> <span style class="">PPs</span> give about 1.2 \mu_B [http://<span style class="">arxiv</span>.org/abs/1006.0589]<br></div></div><div><span style class="">GIPAW</span> gives 1.53 \mu_B [<a href="http://www">http://www</a>.<span style class="">researchgate</span>.net/publication/235566299_Non-collinear_magnetic_moments_in_<span style class="">graphene</span>_with_vacancies]<br>
<br></div><div>It seems that <span style class="">USPP</span> and <span style class="">NCPP</span> could not be the reason for the discrepancy, or?<br></div><div>Could you comment please on the origin of the discrepancies between <span style class="">QE</span> and <span style class="">LAPW</span>?<br>
<br></div><div>Best regards,<br><br></div><div>Martin Gmitra<br></div><div>Uni Regensburg, Germany<br></div></div>