Sorry for my sluggishness - the picture above vise versa - it seems that higher MD.MaxCGDispl gives higher forces, but maybe they will decrease faster... Also my MeshCutoff is already 800 because of Ce
Best wishes, Maxim. 2013/11/25 Максим Арсентьев <ars21031...@gmail.com> > Dear Frank! > > It seems for "normal_main" that you never reach 0.04 eV/Angstrom. How to > fix that? > And here is mt result (seems that MD.MaxCGDispl 0.15 Ang and DM.Tolerance > 0.00001 behave better). > > Best wishes, Maxim. > > > 2013/11/22 <fma...@icp.uni-stuttgart.de> > > A fluctuation in max. forces is normal. Attached is a max. force graph of >> a few CG geometry optimizations I did of isolated molecules. >> >> Further details are in the following PDF: (keyword EggBox Effect) >> http://www.home.uni-osnabrueck.de/apostnik/Lectures/SIESTA-tuto.pdf >> >> So the lower the max. force is, the less CG steps are required in my >> experience and only then can you achieve low MD.MaxForceTol values. >> >> To reduce the max. forces you have to increase the finess of the real >> space grid, by either increasing the MeshCutOff value or making use of >> GridCellSampling: >> >> http://departments.icmab.es/leem/siesta/Documentation/Manuals/siesta-3.1-manual/node47.html >> >> >> Best wishes, >> Frank >> >> >> > I'm doing geometry optimisation if I correctly set it (as I understand >> > it's >> > by default) >> > >> > Best Wishes, Maxim. >> > >> > >> > 2013/11/22 Herbert Fruchtl <herbert.fruc...@st-andrews.ac.uk> >> > >> >> Just to clarify: You are doing MD, not a geometry optimisation, and you >> >> are surprised that the forces don't go to zero? What are you trying to >> >> find? For a minimum energy structure, you need a geometry optimisation. >> >> In >> >> an MD simulation the total (potential+kinetic) energy should remain >> >> constant (depending on your ensemble...), but the forces will vary. >> >> >> >> Herbert >> >> >> >> >> >> On 22/11/2013 08:58, Максим Арсентьев wrote: >> >> >> >>> Dear Sebastian! >> >>> >> >>> My calculations convverge at each MD cycle (about 300-400 SCF cycles), >> >>> but max force oscillate (about 0.1-0.04 eV/anstrom) and I can not >> >>> finish >> >>> MD, and am already at 63 cycle and the calculation cycle is still >> >>> going, >> >>> although the system is quite large and contains 47 atoms. My counter >> >>> question to all: does this oscillation of forces normal? >> >>> I would like to strict DM.Tolerance to 0.00001 (it is VERY important >> to >> >>> accurate calculation of forces) and to limit MD.MaxCGDispl . >> >>> >> >>> Best Wishes, >> >>> Maxim >> >>> >> >>> >> >>> 2013/11/21 Sebastian Caicedo Davila >> >>> <sebastian.caic...@correounivalle.edu.co >> >>> <mailto:sebastian.caic...@correounivalle.edu.co>> >> >>> >> >>> >> >>> 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, <d.otalv...@utwente.nl >> >>> <mailto:d.otalv...@utwente.nl>> <d.otalv...@utwente.nl >> >>> <mailto:d.otalv...@utwente.nl>> 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:*siesta-l-requ...@uam.es <mailto:siesta-l-requ...@uam.es> >> >>>> [siesta-l-requ...@uam.es <mailto:siesta-l-requ...@uam.es>] on >> >>>> >> >>>> behalf of Максим Арсентьев [ars21031...@gmail.com >> >>>> <mailto:ars21031...@gmail.com>] >> >>>> *Sent:*Wednesday, November 20, 2013 7:29 AM >> >>>> *To:*siesta-l@uam.es <mailto:siesta-l@uam.es> >> >>>> *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<m...@nmsu.edu <mailto:m...@nmsu.edu>> >> >>>> >> >>>> >> >>>> You could also try to increase the non-equilibrium contour >> >>>> points. >> >>>> >> >>>> Mahmoud >> >>>> >> >>>> >> >>>> On Nov 18, 2013, at 11:22, "Sebastián Cauce do Dávila" >> >>>> <sebastian.caic...@correounivalle.edu.co >> >>>> <mailto:sebastian.caic...@correounivalle.edu.co>> 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 >> >>>>> <ars21031...@gmail.com <mailto:ars21031...@gmail.com>> >> 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.<sebastian.caic...@correounivalle.edu.co >> >>>>>> <mailto:sebastian.caic...@correounivalle.edu.co>> >> >>>>>> >> >>>>>> >> >>>>>> 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 >> >>>> >> >>> >> >>> >> >>> >> >>> >> >>> -- >> >>> Best wishes, >> >>> Dr. Maxim Arsent'ev >> >>> Laboratory of inorganic synthesis >> >>> Institute of Silicate Chemistry of RAS >> >>> >> >> >> >> >> >> -- >> >> Herbert Fruchtl >> >> Senior Scientific Computing Officer >> >> School of Chemistry, School of Mathematics and Statistics >> >> University of St Andrews >> >> -- >> >> The University of St Andrews is a charity registered in Scotland: >> >> No SC013532 >> >> >> > >> > >> > >> > -- >> > 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 > -- Best wishes, Dr. Maxim Arsent'ev Laboratory of inorganic synthesis Institute of Silicate Chemistry of RAS
