[CP2K:9525] Convergence problem

[Ari Paavo Seitsonen]

Dear Ozan,

  You need to use k points (or a much larger super-cell) to obtain
converged results. you might also need to increase the CUTOFF quite a lot
(otherwise you will get discontinuities in the energies, due to the finite
size of the basis set).

    Greetings from Sunny Paris,

       apsi


2017-10-04 18:15 GMT+02:00 Ozan Dernek <ozand... at gmail.com>:

> Dear all,
>
> As a newbie, I am trying some basic calculations by altering the examples
> provided in CP2K website. The question I want to ask is about finding the
> lattice constant, and optimizing some calculation parameters, such as
> cutoff and rel_cutoff values. To find each of these values, I am running a
> series of calculations varying the subject value, but cannot conclude an
> optimum result. For example, I run the calculations for the lattice
> constant by varying the cell dimensions (from 4.00 to 4.20 Angstrom with
> 0.01 A of increments ) and the atomic positions accordingly. However, the
> total energy keeps increasing with the increasing cell dimensions (I would
> expect to see a minimum around the literature value (around 4.08 A)).
>
> Could you kindly take a look at the attached input file and help me to
> identify the problem ? Plus, I would appreciate any comment and advice
> about the input.
>
> Thanks in advance,
>
> Ozan Dernek
> Phd Student
> Comp. Mat. Sci. Group
> Phys. Dept., Middle East Technical University
>
> --
> You received this message because you are subscribed to the Google Groups
> "cp2k" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to cp2k+uns... at googlegroups.com.
> To post to this group, send email to cp... at googlegroups.com.
> Visit this group at https://groups.google.com/group/cp2k.
> For more options, visit https://groups.google.com/d/optout.
>



-- 
-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
  Ari Paavo Seitsonen / Ari.P.S... at iki.fi / http://www.iki.fi/~apsi/
    Ecole Normale Supérieure (ENS), Département de Chimie, Paris
    Mobile (F) : +33 789 37 24 25    (CH) : +41 79 71 90 935
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20171004/5ad9fa79/attachment.htm>