<div dir="ltr">Thanks very much for you help, I have made the changes that you suggested.<div><br><div>In a related calculation, I created a supercell of a gold lattice and introduced a chromium atom in order to model chromium atoms in substitutional sites. I followed the guidelines in the users guide and everything in the calculation seemed to go well. However I noticed that the a, b and c parameters had been slightly reduced (around 5%) from the values that I had entered originally. Am I correct in thinking that this adjustment was made to account for the new lattice configuration? I have attached the struct file from the calculation.</div>
<div><br></div><div style>Thanks again in advance,</div><div>Bob Larson</div></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Mon, Jan 7, 2013 at 3:38 AM, Peter Blaha <span dir="ltr"><<a href="mailto:pblaha@theochem.tuwien.ac.at" target="_blank">pblaha@theochem.tuwien.ac.at</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">I checked your scf and struct files:<br>
<br>
a) Please use identical RMT for Ru for the 2 cases. Since RuO2 forces you to have r(Ru)=2.0), use it also for hcp-Ru.<br>
(I don't think the effect will be very large, but ...)<br>
<br>
b) You cannot do these calculations with just ONE k-point !<br>
For metallic Ru you should use something like "10000" when running<br>
x kgen;<br>
and since also RuO2 is metallic, use a similar number (maybe 5000, since<br>
RuO2 contains more atoms/cell than Ru).<br>
<br>
c) Finally, check how much the differences in :RTO depend on<br>
RKMAX (case.in1; 7 by default). Once you have the first scf-calculation<br>
saved, increase it to 8, do another run_lapw and compare the resulting RTO<br>
<br>
The possible errors are not so easy to quantify. Besides computational<br>
parameters (which you can check as mentioned above), the error from DFT is hard to quantify and only from experience for a certain quantity in comparison with experiment we can estimate it.<br>