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Thanks for the answers to question 1.<br>
So rrkjus from quantum espresso are not norm conserving (indeed I'm
using rrkjus psps).<br>
<br>
I supposed that rrkj means a pseudo created according to the rrkj
scheme presented in PRB 41, 1227 (1990). <br>
In that paper the proposed psps are norm-conserving. Is that
correct?<br>
Is there any another paper I should look for?<br>
<br>
Regards,<br>
Davide<br>
<br>
On 01/31/2011 12:41 PM, Davide Sangalli wrote:
<blockquote cite="mid:4D469FD8.9000809@gmail.com" type="cite">
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Dear forum,<br>
I'm doing calculations with rrkj pseudo-potentials.<br>
<br>
As far as I understand rrkj are norm-conserving psps and only ecut
should be checked, while ecutrho=4*ecut should be fine.<br>
From this I guess that the ecutrho paramater, if increased, should
not influence the convergence.<br>
<br>
I did some test and I saw that this is not true. Increasing
ecutrho (at fixed ecut) the results changes significantly. For
example the elements of the stress tensor changes more than 15
Kbar (in some case even more) moving ecutrho from 140 to 300 Ry
(with ecut=35 Ry). Here I was testing FeO, CoO and NiO, with
pbe/rrkj psps for all thee elements.<br>
<b>Question 1: Why ?<br>
</b>(I saw that in the psps header Rcut and Rcut US are different
... ?)<br>
<br>
I did these checks even because I would like to perform
calculations using vanderbilt psp (for some elements) together
with rrkj psp (for other element?).<br>
<b>Question 2: Is there any counter indication in doing that ?<br>
</b><br>
Thanks and best regards,<br>
Davide Sangalli<br>
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