On Mon, Oct 20, 2008 at 1:41 AM, Agostino Migliore <amigliore at cmm.upenn.edu>wrote:
> Hello Alex > > Since, you have transition metals in your system, it could help you to > introduce an electronic smearing and then progressively reduce it until > you get the solution without any orbital fractional occupations. > Then, from the attached file I saw that you are using mixing_beta = > 0.7D0. Did you try something like mixing_beta = 0.5 or similar (perhaps > you already did, but I don't know) and also mixing_mode = 'plain' > (although I know that the local_TF mode may be good for highly > inhomogeneous systems). > Finally, your system includes Ti atoms, which have d electrons. Have you > tried to use the Hubbard U correction scheme implemented in pwscf? Also > irrespective of your convergence problem, it could provide you with a > better description of the electronic structure (indeed, I don't have > direct experience on Ti, but I have on Fe, and the Hubbard U correction > term works well). > I hope something I said can help you. > > Best regards, > Agostino Migliore > CMM, Department of Chemistry, Philadelphia > > > Quoting Alexej Mazheika <alex.mazheika at gmail.com>: > > > Dear all > > > > I perform the calculations of surface with adsorbed cluster Ag4/TiO2 and > > have a problem with convergence during SCF-procedure. It does not > converge. > > In order to eliminate it I tried the shown methods in the user_guide: to > > decrease mixing beta, to increase mixing ndim, to increase ecutwfc and > > ecutrho. But it didn't help me. Is there any other methods to solve such > > problem? The input file is here attached. > > > > Best regards > > Alex Mazheika, Research Institute for phys. and chem. problems, Minsk, > > Belarus > > > > > I tried to use mixing_beta 0.3, mixing_ndim 10, mixing_mode = 'local-TF' and I changed the diagonalization to 'diis'. I performed the calculations with such parameters: occupations = 'smearing', degauss = 3.7D-3, smearing = 'gaussian'. And then the covergance was achieved. Thank you for recommendations Best regards Alex Mazheika, Research Institute for phys. and chem. problems, Minsk, Belarus -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20081022/a9f08e76/attachment.htm
