Dear Giuseppe Regarding the first part, I know that i have a near optimized structure, since it was fully optimized by SIESTA. Now, I want to perform some DFT+U calculations with espresso.... Regarding your last recomendation.... It is always on my mind, but it is not so easy :-) Thanks! Regards Ricardo
-------------------------------------------- Dr. Ricardo Faccio Prof. Adj. de F?sica Av. Gral. Flores 2124. CC 1157. CP 11800. Phone: + 598 2 924 9859 Fax: + 598 2 924 1906 Web: http://cryssmat.fq.edu.uy/ricardo/ricardo.htm --------------------------------------------- El 20/01/2011, a las 03:43, Giuseppe Mattioli <giuseppe.mattioli at mlib.ism.cnr.it > escribi?: > >> to your recent PRL). I optimized the structure with gamma point with >> 25 and 250 ecut and rhocut respectively > > Only a little suggestion (I've performed some similar calculations): > I suppose > that your Co pseudopotential is quite far from convergence at 25 > Ry... If > your calculation of the isolated molecule at gamma is converged at > 25 Ry > PLEASE SHARE THE PSEUDOPOTENTIAL...:-) !!!! I suppose also that forces > calculated by using a higher pw cutoff and a well converged k-point > mesh on > the gamma/25 Ry geometry (molecule+surface, of course) will be still > quite > high. Perhaps you should consider to migrate your calculation to a > better > machine... > HTH > > Yours > > Giuseppe Mattioli > > > On Thursday 20 January 2011 03:26:27 Ricardo Faccio wrote: >> Dear nicola >> Thanks gr your email, i would like to take the opportunity and ask >> you >> a further question. I have a similar situation than Jos?. I'm work >> ing >> with a cobalt porphyrin deposited over a metallic substrate (similar >> to your recent PRL). I optimized the structure with gamma point with >> 25 and 250 ecut and rhocut respectively. It takes almost the 100% of >> my 8Gb RAM quad core computer. Now i want to get a reasonably DOS fir >> this system, but i need more k-points, and thus I will need more RAM >> memory. Would you recommend anything else for getting a good DOS for >> my quad core 8 GB RAM machine? >> Thank you in advance. >> Ricardo >> >> -------------------------------------------- >> Dr. Ricardo Faccio >> Prof. Adj. de F?sica >> >> Av. Gral. Flores 2124. CC 1157. CP 11800. >> Phone: + 598 2 924 9859 >> Fax: + 598 2 924 1906 >> Web: http://cryssmat.fq.edu.uy/ricardo/ricardo.htm >> --------------------------------------------- >> >> El 19/01/2011, a las 21:54, Nicola Marzari >> <nicola.marzari at materials.ox.ac.uk >> >>> escribi?: >>> >>> Given your system size, it's likely that gamma point >>> is good enough - a full relaxation with 18 Ry cutoff and >>> the gamma point would bring you very very close to the correct >>> result. >>> >>> Then, try 30 Ry and Gamma point - do the results change a lot ? >>> Probably note, and maybe 25 Ry is enough (there are tests of >>> the C ultrasoft on the pseudopotential page). I'd assume a dual of >>> 8, i.e. a cutoff for the charge density of 8 times the cutoff on the >>> w
