Thanks.
I had made some tests before. I am sure that 120 Ryd
is well enough for the total energy to be converged.
But I did not consider the convergence of the forces.
I would check it.
--- Gul Rahman <[EMAIL PROTECTED]>写道:
>
>
> Hi 赖 林
>
> I think some one has discussed this problem few
> months back. There are some parameters which can
> effect the forces on atoms and one of them is
> MeshCutoff which is 120 Ry in your case.
> I think u need to increase it and see what
> happens, the other parameter is Electronic temp. You
> have to play with these.
> VASP gives you minimum forces bcos it uses US-PP
> for which u need small Mesh-Cutoff but in SIESTA u
> have to check the forces with Mesh-Cutoff.
> Hope someone else will also give some idea.
> G.Rahman
>
> Hi,all.
>
> The forces seem to be too large and keep oscillating
> in my calculations with siesta. Sometimes the force
> will suddenly reach the force tolerance and the
> relaxation is completed. But in my experiences, the
> forces always become smaller and smaller and reach
> the convergence finally in other DFT programs, such
> as VASP, CATEP.
>
> Maybe there is something wrong with my input
> parameters. Could anyone give me some advice?
>
> The input file has been attached. The grep.txt file
> contains the total forces during the relaxation. It
> is the same in other calculations with a smaller
> number of atoms.
>
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> ahman
>
> Computational Physics Lab
> Department of Physics
> University of Ulsan
> Republic of Korea "Whoever rules magnetism rules
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