Dear Reza, Le 13-set-2010 ? 20:49, reza shidpoor <rezashidpoor at gmail.com> a ?crit :
> > Dear Gabriele > > Thank you for your comments in pwscf forum. > > I performed your suggestion that ecut is set to 32 Ry. The structure was > relaxed So you can confirm that with this cutoff it works, do you? > and I repeated with ecut=20 , 22 Ry. Why do you want to do so? If the cutoff id too low the forces are not described correctly and the ralaxation algorithm might fail to converge. > It seems that the structure did not relaxed with this point " > > ............. > ........... > the Fermi energy is -5.0636 ev > > ! total energy = -262.94392529 Ry > Harris-Foulkes estimate = -262.94392533 Ry > estimated scf accuracy < 0.00000006 Ry > > The total energy is the sum of the following terms: > > one-electron contribution = -323.90644330 Ry > hartree contribution = 178.85727642 Ry > xc contribution = -104.02662243 Ry > ewald contribution = -13.85257067 Ry > smearing contrib. (-TS) = -0.01556530 Ry > > convergence has been achieved in 2 iterations > > Forces acting on atoms (Ry/au): > > > negative rho (up, down): 0.998E-04 0.000E+00 > atom 1 type 1 force = 0.00000000 0.00223711 0.00000000 > atom 2 type 1 force = -0.00165978 -0.00111856 0.00000000 > atom 3 type 1 force = 0.00165978 -0.00111856 0.00000000 > > Total force = 0.003608 Total SCF correction = 0.000988 > SCF correction compared to forces is too large, reduce conv_thr Besides increasing the cutoff, you might need to decrease this threshold on order for the forces to be perfectly consistent with the total energy. > > The maximum number of steps has been reached. > > End of BFGS Geometry Optimization > Begin final coordinates > > ATOMIC_POSITIONS (angstrom) > Au 0.000000000 0.248435531 0.000000000 > Au -2.339313337 1.325352234 0.000000000 > Au 2.339313337 1.325352234 0.000000000 > End final coordinates > > ........................ > ........................ > > Questions : > > 1) The electron_maxstep is equaled 100. What is purpose of "number of states" > ? ??? You are confusing number of states with number of electrpnic steps and perhaps also with ionic steps. Please spend some time reading the manual and some examples or tutorials. > > 2) Should I consider system to be semiconducting If I want to simulate > 4-atoms cluster? If you are not sure, you can treat your system as metallic with a small smearing and then, if it turns out to have a gap, reduce/remove the smearing. GS > > > Best Regards, > Reza.Shidpour > SUT > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100914/016cd9ca/attachment-0001.htm
