<div dir="ltr"><div>Dear Daniele,</div><div><br></div><div> My few thoughts,</div><div><br></div><div> What you could use instead of "MULTIPLICITY" is the keyword "FIXED_MAGNETIC_MOMENT", <a href="https://manual.cp2k.org/trunk/CP2K_INPUT/FORCE_EVAL/DFT/SCF/SMEAR.html#list_FIXED_MAGNETIC_MOMENT">https://manual.cp2k.org/trunk/CP2K_INPUT/FORCE_EVAL/DFT/SCF/SMEAR.html#list_FIXED_MAGNETIC_MOMENT</a> , if you indeed try to force a magnetic moment. Usually this is, however, not done but the system is let to relax its electronic structure and find the final magnetisation self-consistently. "MULTPLICITY" is meant for systems with well-defined electronic shells (open- or closed-shell), with a gap between the occupied and un-occupied states, whereas with the smearing one goes for different tools and keywords. The suggestion was to used the keyword "MAGNETIZATION" to get a reasonable initial guess and then let the system relax and find its magnetic moment; if you have convergence problems, you might try with "FIXED_MAGNETIC_MOMENT" in the first calculation, once that converges you read the previous density (densities, including the spin polarisation) and try without any constraint on the magnetisation.</div><div><br></div><div> Good Luck from Half-Sunny Paris,</div><div><br></div><div> apsi<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Le mer. 28 août 2019 à 11:42, Daniele Ongari <<a href="mailto:daniel...@gmail.com">daniel...@gmail.com</a>> a écrit :<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Hi Tiziano, <br>I'm interested in this topic because I have problem to make materials (MOFs) with Fe converge and I want to start to the bulk Fe as a test case.<br><br>I wonder how is your suggestion supposed to work.<br>1) Without specifying the system MULTIPLICITY this is by default 0 (which is treated as 1 in CP2K) that means that no broken symmetry is occurring: spin1 and spin2 will be rescaled and basically the effect of specifying the MAGNETIZATION is null<br>2) If considering that the system has 16 Fe atoms, one used 1+16*2.3= 37.8 as MULTIPLICITY (assuming ferromagnetic configuration), CP2K aborts with the error "An integer type object was expected".<br><br>So, how can someone specify a MAGNETIZATION that doesn't sum up into an integer total magnetization?<br><br>The problem I see is another, that I'm not able to make the calculation converge with MAGNETIZATION 2 and MULTIPICITY 1+16*2=33 (so no problems with non-integer numbers), but this is a problem to solve in the &MIXING section, right?<br>Do you have any working settings for make the bulk Fe converge? I think you managed to do so for the Delta-test of Stefaan Cottenier.<br><br>Thank you very much for your help<br><br>Daniele<br><br><br>Il giorno giovedì 26 aprile 2018 17:35:33 UTC+2, Tiziano Müller ha scritto:<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hi Unmesh
<br>
<br>Am 25.04.2018 um 12:18 schrieb Unmesh Mondal:
<br>> I am new to cp2k and wish to do a spin polarised calculation of bulk
<br>> Iron (Fe : 16 atoms, gamma point). Switching on UKS (spin unrestricted
<br>> Kohn Sham) ensures the spin polarised part and the MULTIPLICITY " "
<br>> ensures the initial spin state of the whole system.
<br>
<br>Are you sure? Check your output right below "Guess for atomic kind: Fe".
<br>This should tell you the used initial spin state.
<br>
<br>With CP2K 5.1 and later you can use the MAGNETIZATION keyword for the
<br>KIND section (with a value of 2.3 for iron) to get a proper initial
<br>state, see
<br>
<br><a href="https://manual.cp2k.org/trunk/CP2K_INPUT/FORCE_EVAL/SUBSYS/KIND.html" rel="nofollow" target="_blank">https://manual.cp2k.org/trunk/CP2K_INPUT/FORCE_EVAL/SUBSYS/KIND.html</a>
<br>
<br>If you are using an older version (<5.1) use the Broken Symmetry section
<br>instead to achieve the same thing:
<br>
<br><a href="https://manual.cp2k.org/cp2k-4_1-branch/CP2K_INPUT/FORCE_EVAL/SUBSYS/KIND/BS.html" rel="nofollow" target="_blank">https://manual.cp2k.org/cp2k-4_1-branch/CP2K_INPUT/FORCE_EVAL/SUBSYS/KIND/BS.html</a>
<br>
<br>Best regards,
<br>Tiziano
<br>
<br>--
<br>Tiziano Müller
<br>University of Zurich
<br>Department of Chemistry
<br>Winterthurerstrasse 190
<br>CH-8057 Zürich
<br>
<br>Tel: +41 44 63 54234
<br><a href="http://www.chem.uzh.ch" rel="nofollow" target="_blank">www.chem.uzh.ch</a>
<br><a rel="nofollow">tiz...@chem.uzh.ch</a>
<br></blockquote></div>
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</blockquote></div><br clear="all"><br>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr">-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-<br> Ari Paavo Seitsonen / <a href="mailto:Ari.P....@iki.fi" target="_blank">Ari.P....@iki.fi</a> / <a href="http://www.iki.fi/~apsi/" target="_blank">http://www.iki.fi/~apsi/</a><br> Ecole Normale Supérieure (ENS), Département de Chimie, Paris<br> Mobile (F) : +33 789 37 24 25 (CH) : +41 79 71 90 935<br></div></div></div></div></div></div>