[Pw_forum] poor k-points convergence, ghost states ?
Hi, I am trying to reproduce a paper on AgSbTe. I am having problems to obtain convergence against the number of k-points. With a supercell of 8 atoms, I do not have convergence with 26x26x26 Monkhorst-Pack mesh. I think that this is a quite dense mesh and I should have obtained convergence much before. My student is also having troble to complete the band calculations. I am using BHS pseudopotentials for Sb and Te, and US for Ag. I suspect that I have ghost states. Is there other possible reasonable cause? Thanks -- Eduardo Menendez University of Chile -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20080825/450c947d/attachment.htm
[Pw_forum] lelfield and lberry
Dear PWSCF users, I am now running a calculation of strained STO and try to calculate its spontaneous polarization based on Berry phase method. I try two different ways: 1) run a self-consistent calculation turning on lelfield=.true. and set efield=0.0 2) first run a self-consistent calculation and then run a non-self-consistent calculation turning on lberry=.true. Are these two method equivalent? When I try these two methods on the same system, method 1) works well but method 2) fails because "probably because G_par is NOT a reciprocal lattice vector". I notice that (in the version 4.0) in the two subroutines bp_c_phase.f90 and c_phase_field.f90 the definition of gpar are different by a factor DBLE(nppstr)/DBLE(nppstr-1). But I think these two gpar should be the same thing? I just want to ask whether the option lberry is fully tested and compatible with 'lelfield = .true.'. Thank you very much for your help. Hanghui Chen Department of Physics Yale University -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20080825/bff942d5/attachment.htm
[Pw_forum] spin orbit
Dear Ali This is a rather general question that you are asking here. Dimensionality is indeed playing a crucial role in magnetic properties and particularly in magnetic anisotropy. To be able to isolate the role of edge atoms, for instance, in the magnetic anisotropy energy one should be able to decompose the total energy as the sum over the various atomic sites. I know that it has been done in FLAPW like the FLEUR code (see PRB 73, 104427 (2006)) but I doubt that it has been implemented in PWscf (correct me if I'm wrong..). It is also quite commonly done in tight-binding schemes but with the usual limitations of TB.. best wishes cyrille -- == Cyrille Barreteau | phone : +33 (0)1 69 08 29 51 CEA Saclay | fax : +33 (0)1 69 08 84 46 DSM/IRAMIS/SPCSI | email cyrille.barreteau at cea.fr Batiment 462 | 91191 Gif sur Yvette Cedex FRANCE http://iramis.cea.fr/Images/Pisp/cbarreteau/cbarreteau_fr.html == ali kazempoor wrote: >Dear All >first,I want to see the importance of spin-orbit interaction in compound MnAs >nanowire(~1 nm). This is because that we know that the reduction of >coordination number from bulk to nanscale lead to higher value for magnetic >moment ,also increasion of anisotropy. How and by when(see which parameter >like energy , magnetic moment) ,can I understand that in my nanostructure >system , the addition of spin-orbit has substantially effect in results or not? >As you know, in nanostructures the edge atoms play essential role in cohesive >energy.moreover if we have magnetic atoms in the edge of nanomaterial,the >anisotropy axis (hard and easy) are alternatively varied from when nonmagnetic >atom sit on the edge. >How can I calculate the easy and hard axis of MnAs nanowire by highlighting >the edge atoms contribution?(which kpoint and thereshold are enough for >obtaining correct results)? >thanks >Ali Kazempour >Isfahan University of technology, Isfahan,Iran > > > > >___ >Pw_forum mailing list >Pw_forum at pwscf.org >http://www.democritos.it/mailman/listinfo/pw_forum > >
[Pw_forum] Pseudopotential GGA Co with spin orbit
Hello everyone. I need a pseudopotencial GGA with spin orbit for the Co. If someone can help me, thank you very much. ?? Sincerely, Alvaro A. S. Santos Universidade Federal Fluminense - RJ - Brazil Novos endere?os, o Yahoo! que voc? conhece. Crie um email novo com a sua cara @ymail.com ou @rocketmail.com. http://br.new.mail.yahoo.com/addresses -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20080825/63663318/attachment.htm
