On Thu, 2014-02-06 at 12:58 +0100, Thomas Gruber wrote: > I attached 2 inputs files. One with smaller volume works and one with > greater volume with the corresponding *.out file, which works not. Since > I have already done phonon calculations for 5 different volumes, I don't > want to change the FFT dimension. I fixed it to 48 48 200 and the not > fixed FFT dimension would be 50 50 200. > Any suggestions?
it works if you reduce by a little bit "ecutrho" from its default value 4*ecutwfc. The problem is that if you keep the FFT grid fixed, you may "miss" a few G-vectors. The algorithm that divides G-vectors into shells of vectors transforming into each other cannot work if a shell is incomplete. Alternatively: remove symmetry, since such algorithm is used only for symmetrization of the charge density. I have no better ideas right now: finding an algorithm that is guaranteed to work if the FFT grid is not sufficient to accommodate the G-vector sphere up to G^2< ecutrho may require a serious effort Paolo > Regards, > > Thomas Gruber > > On 02/06/2014 12:00 PM, pw_forum-request at pwscf.org wrote: > > Message: 11 > > Date: Wed, 05 Feb 2014 19:45:00 +0100 > > From: Paolo Giannozzi<paolo.giannozzi at uniud.it> > > Subject: Re: [Pw_forum] Error in routine sym_rho_init_shell "lone > > vector" with fixed FFT dimension > > To: PWSCF Forum<pw_forum at pwscf.org> > > Message-ID:<1391625900.28572.9.camel at pania.fastwebnet.it> > > Content-Type: text/plain; charset="UTF-8" > > > > Very strange. The error signals a failure in the algorithm > > that finds shells of G-vectors that transform into each other > > under symmetry operations. It might however be due to too small > > FFT dimensions, maybe. It is hard to figure out what happens > > without an input file. > > > > P. > > > > On Wed, 2014-02-05 at 15:49 +0100, Thomas Gruber wrote: > >> > Dear all, > >> > > >> > I try to determine the heat capacity at constant pressure and calculate > >> > the phonon DOS at different volumes. Since I get jumps in free energy > >> > when the FFT dimension change, I fix it to the one from the starting > >> > volume. But for on of my systems everything works fine up to 4% > >> > isotropic increase of the cell axis and at 5% I get the following error > >> > in the starting scf calculation: > >> > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% > >> > Error in routine sym_rho_init_shell (2): > >> > lone vector > >> > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% > >> > This error does not show up, when I do not fix the FFT dimension. > >> > Without fixing the FFT dimension the FFT dimension is different to the > >> > one I choose. > >> > Is there a way to keep my fixed FFT dimension and get rid of this error? > >> > > >> > Thanks in advise. > >> > > > -- Paolo Giannozzi, Dept. Chemistry&Physics&Environment, Univ. Udine, > > via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax > > +39-0432-558222 > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum -- Paolo Giannozzi, Dept. Chemistry&Physics&Environment, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222
