Hello Diana!! Thanks a lot for your suggestion! I'll give it a try and maybe I'll be bothering you again, if it is not an imposition, of course.
Gracias de nuevo, y saludos desde tu tierra! Sebastian Caicedo Davila Bionanoelectronics Research Group School of electrical and electronics engineering Universidad del Valle Cali - Colombia. On Nov 21, 2013, at 11:02 AM, <[email protected]> <[email protected]> wrote: > Hello Sebastian, > > I have had similar problems with convergence of the scf cycle. They were > solved when I changed from Pulay mixing to Broyden mixing for the charge > density. > > Usually if something doesn't converge in 250 cycles, it probably never will. > Also you can play with the DM.Tolerance. For very difficult systems I set it > to 0.0008 and then restart from that DM file with a stringer convergence > criterion. > > Here is the settings I am using for my calculations: > > #--------------------Convergence of SCF------------------------------- > MeshCutoff 200.0 Ry # Default value PW cutoff for grid > > > MaxSCFIterations 250 # Maximum number of SCF iter > DM.NumberBroyden 3 > DM.MixingWeight 0.01 # New DM amount for next SCF cycle > DM.Tolerance 0.0001 # Tolerance in maximum difference > DM.UseSaveDM .false. # to use continuation files > > DM.NumberKick 100 > DM.KickMixingWeight 0.01 > #---------------------------------- > > Suerte! > > PS: yo tambien soy caleña! > > Diana M. Otálvaro > PhD Candidate > > Computational Material Science > MESA+ Institute of Nanotechnology > University of Twente. > Enschede, Nederland > From: [email protected] [[email protected]] on behalf of Максим > Арсентьев [[email protected]] > Sent: Wednesday, November 20, 2013 7:29 AM > To: [email protected] > Subject: Re: [SIESTA-L] Convergence problem on heterostructure. > > I forgot to tell you - besides DM.MixingWeight 0.05 I also set > PAO.EnergyShift to 65 meV as > herehttp://www.nature.com/nnano/journal/v7/n9/extref/nnano.2012.127-s2.txt . > > Best wishes, > Dr. Maxim Arsent'ev > Laboratory of inorganic synthesis > Institute of Silicate Chemistry of RAS > > > 2013/11/18 Mahmoud Hammouri <[email protected]> > You could also try to increase the non-equilibrium contour points. > > Mahmoud > > > On Nov 18, 2013, at 11:22, "Sebastián Cauce do Dávila" > <[email protected]> wrote: > >> Thank you very much for your suggestion. I will give it a try! >> >> Sebastián Caicedo Dávila >> Bionanoelectronics research group >> School of electrical and electronics engineering >> Universidad del Valle >> Cali - Colombia >> >> >> On 18/11/2013, at 11:50, Максим Арсентьев <[email protected]> wrote: >> >>> I also try some siesta only six months, but for a more heterogeneous >>> structure I noticed that the reduction DM.MixingWeight reduces oscillations >>> in convergence, so try to play with it (decrease DM.MixingWeight). See >>> http://www.nature.com/nnano/journal/v7/n9/extref/nnano.2012.127-s2.txt >>> Maybe someone will tell something else. >>> >>> >>> 2013/11/18 Sebastian Caicedo D. <[email protected]> >>> Dear Siesta/Transiesta users, >>> >>> I've been using the software for a couple months and made some calculations >>> of InAs and InP unit cell quite successfully. Now I intend to work on >>> transiesta calculations of a heterostructure of both these materials (InAs >>> bulk with InP barriers). As a first approach I want to simulate a couple of >>> InAs unit cells and the barriers shall be unit cells of InP, just to get a >>> qualitative idea. The electrodes .TSHS files were obtained from the >>> previous calculations of the InAs unit cell. I wanted first to run a siesta >>> calculation of the whole heterostructure, so I can take a look at the >>> eigenvalues and define a correct value for the parameter >>> TS.ComplexContour.Emin, as suggested in the manual. >>> >>> The structure has 120 atoms and I'm using LDA Pseudopotentials, obtained >>> from the siesta webpage. (In Pseudo includes semicore electrons, so we have >>> enough electrons to build a zinc-blende structure). The issue is that after >>> 1000 SCF steps, the energy doesn't converge at all. I'm doing a Gamma-point >>> calculation, but even when I make the k-grid 1x1x15 it doesn't work either. >>> >>> I used the same MeshCutoff as for the individual materials unit cell an >>> 200Ry and I increased the Energy Shift, so the calculation would be a bit >>> faster though less precise. >>> >>> I attach the Input (INPUT.fdf, STRUCTURE.fdf) and output files. >>> >>> I would really appreciate any suggestions. >>> >>> sincerely >>> >>> Sebastian Caicedo Davila >>> Bionanoelectronics Group >>> School of Electrical and Electronics Engineering >>> Universidad del Valle >>> Cali-Colombia >>> >>> >>> >>> -- >>> Best wishes, >>> Dr. Maxim Arsent'ev >>> Laboratory of inorganic synthesis >>> Institute of Silicate Chemistry of RAS > > > > -- > Best wishes, > Dr. Maxim Arsent'ev > Laboratory of inorganic synthesis > Institute of Silicate Chemistry of RAS
