<div dir="ltr">Dear Prof Peter Blaha,<br>I have calculated spin polarised calculation in Gd(2*2*2)for Cd<br>impurity and the results,hyperfine field, magnetic moment,electric <br>field gradient reasonably matches with available literature.actually<br>
I am interested to find out the electric field gradient of Cd in Gd at room<br>temperature which is paramagnetic, and thats why I have started unpolarised<br>calculation,and faced the problem.So how to proceed in this regard?<br>
<br>with regards<br>Susanta kumar Mohanta<br><br><br><div class="gmail_quote">On Tue, Sep 16, 2008 at 10:51 AM, Peter Blaha <span dir="ltr"><<a href="mailto:pblaha@theochem.tuwien.ac.at">pblaha@theochem.tuwien.ac.at</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">I'm not surprised that a Gd-supercell does NOT converge in an<br>
unpolarized calculation.<br>
<br>
You have to consider the underlying physics: Gd metal has 7 4f<br>
electrons, thus in a polarized calculation this gives a rather stable<br>
situation, i.e. "all" 7 spin-up states are occupied, but all 7 spin-dn<br>
states empty.<br>
In an unpolarized case you must put 7 electrons into "3.5 states" (each<br>
state takes now 2 electrons!) and it is rather naturally that this will<br>
cause problems.<br>
<br>
The VERY efficient mixer seems to manage this for pure Gd, but in the<br>
supercell there are many more degrees of freedom and thus convergence is<br>
much more difficult. Eventually, switching to TEMP and a rather large<br>
broadening will help to converge.<br>
<br>
In any case, you have to ask yourself: what should this calculation be<br>
good for ?? Even above the Neel/Curie-point one has local magnetic<br>
moments (only the long range order has gone).<br>
<br>
susanta mohanta schrieb:<br>
<div><div></div><div class="Wj3C7c">><br>
> Dear all,<br>
><br>
> I have finished spin polarised calculation for Gd(2*2*2 supercell) with Cd<br>
> impurity.But When I started with same structure for unpolarised calculation<br>
> with RKMAX=7.5:GMAX=14 and 300kpoints(to begin with),the computation<br>
> doesn;t seems to converge.After 200 cycle we noticed that both charge and<br>
> energy are oscillating.So please help me in this regard.I have also<br>
> calculated<br>
> unpolarised calculation for pure Gd.So what may be the problem?<br>
><br>
> with regards<br>
> susanta<br>
><br>
> --<br>
> SUSANTA K MOHANTA<br>
> RESEARCH SCHOLAR<br>
> DEPT.OF PHYSICS<br>
> IIT KHARAGPUR<br>
> *****************************<br>
><br>
><br>
</div></div>> ------------------------------------------------------------------------<br>
><br>
> _______________________________________________<br>
> Wien mailing list<br>
> <a href="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a><br>
> <a href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br>
_______________________________________________<br>
Wien mailing list<br>
<a href="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a><br>
<a href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br>
</blockquote></div><br><br clear="all"><br>-- <br>SUSANTA K MOHANTA<br>RESEARCH SCHOLAR<br>DEPT.OF PHYSICS<br>IIT KHARAGPUR<br>*****************************<br>
</div>