On Mon, Apr 21, 2014 at 12:03 AM, David Foster <davidfoster751 at yahoo.com> wrote: > Dear Yun > Thanks for your rapid answer. Considering your answer, I have two more > questions: > > 1- In the system I have carbon monoxide. carbon atom has 4 electron in its > valance. between O and C there is a triple bond. So, carbon may have one > unpaired electron that needs spin-polarization defined. Is it right?
wrong. electrons cannot be "assigned" to individual atoms, they occupy "molecular" orbitals. please help yourself to a little quantum chemistry refresher. > 2- Surface of metals due to the charge density near to the surface needs > spin-polarization. Is it right? wrong. you need spin polarization only if you have unpaired electrons.. > One more point. I have prepared input with one graphical program. When I see > the input file with XCrysDen, in the primitive form everything is OK, but in > conventional form, three to four Pd atoms in the edge of cell seems to be > missing!!!! that is just visualization. probably your initial geometry has some rounding errors in the positions. axel. > Regards > > David Foster > > Ph.D. Student of Chemistry > > -------------------------------------------- > On Sun, 4/20/14, Yun Wang <yun.wang at griffith.edu.au> wrote: > > Subject: Re: [Pw_forum] fluctuation in SCF energies of CO adsorbed on Pd110 > To: "PWSCF Forum" <pw_forum at pwscf.org> > Date: Sunday, April 20, 2014, 2:41 PM > > Hi David,I think > you need not consider the spin polarization for this system, > which will accelerate the > convergancy.Cheers,Yun > > > > > > On Mon, Apr 21, 2014 > at 2:20 AM, David Foster <davidfoster751 at yahoo.com> > wrote: > > > Dear users > > > > I have prepared an input for interaction between CO and > Pd(110). I optimized 3*3*3 supercell of Pd bulk, and then > cleaved a 110 surface and constructed a slab. I inserted CO > molecule which has been optimized with QE5.0.2 in it. Now, I > try to optimize this mixed system (CO+Pd(110)). > > > > > > My main problem is that in scf I see the fluctuation in > energies. My input and output has been attached. In all > calculations I used QE5.0.2 and the same USPP. I used PBE > DFT in the PP. I used nspin=2 due to the presence of oxygen > atom. I introduced start_magnetization for all species. I > fixed three bottom layers in the cell. I used ibrav=14 to > optimize bulk phase of Pd, and didn't change it in all > computation. > > > > I used degauss=0.001RY. In addition I used smearing > technique for both bulk and slab. > > > > The run is continuing, but I think finally, I will encounter > with problem. > > > > Any idea for rapid convergence and solve the issue in > fluctuation energy is appreciated. > > > > > > > > > > Regards > > > > David Foster > > > > Ph.D. Student of Chemistry > _______________________________________________ > > Pw_forum mailing list > > Pw_forum at pwscf.org > > http://pwscf.org/mailman/listinfo/pw_forum > > > > -- > > Dr. Yun Wang > Research Fellow > Centre for Clean Environment and Energy > Griffith School of Environment > Gold Coast Campus, Griffith University > QLD 4222, Australia > Tel:(61-7) 5552 8456 > Fax:(61-7) 5552 8067 > > > > > -----Inline Attachment Follows----- > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum -- Dr. Axel Kohlmeyer akohlmey at gmail.com http://goo.gl/1wk0 College of Science & Technology, Temple University, Philadelphia PA, USA International Centre for Theoretical Physics, Trieste. Italy.
