<div dir="ltr"><span style="font-size:12.8px">How to decide that? For inverse spinel (CuFe2O4) with FCC structure (56 atoms), what is the minimum number of K point (approx) required?</span><br><div><span style="font-size:12.8px"><br></span></div><div><span style="font-size:12.8px">There is no such thing like minimum or maximum. You need to look at your bands. If it is smooth, then the number is fine. To be on a safer side, I would recommend 50 along each of the high symmetry points. If your cell is too small, then you need to increase and vice versa.</span></div><div><span style="font-size:12.8px"><br></span></div><div><span style="font-size:12.8px">Regards</span></div><div><span style="font-size:12.8px">Saif</span></div><div><span style="font-size:12.8px">Department of Physics, UFJF, Brazil</span></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Oct 23, 2017 at 2:55 PM, Madhurya Chandel <span dir="ltr"><<a href="mailto:madhurya.svnit@gmail.com" target="_blank">madhurya.svnit@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div><div><div>Thank you for your kind reply. <br><br>The number of points is free, but you have to take it large enough that the bands look smooth and not jagged.<br></div><br>How to decide that? For inverse spinel (CuFe2O4) with FCC structure (56 atoms), what is the minimium number of K point (approx) required?<br><br>Also, the continuity analysis done by bands.x<br></div>what is the continuity analysis?<br><br></div><br> You just need to go through the high symmetry points. The link may be useful: <a href="http://web.mit.edu/xcrysden_v1.5.60/www/XCRYSDEN/doc/kpath.html" target="_blank">http://web.mit.edu/xcrysden_v1<wbr>.5.60/www/XCRYSDEN/doc/kpath.<wbr>html</a>)<br>Thank you for your help but I already referred this <br><br></div>With regards<br></div>Madhurya <br><div><div><br></div></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Oct 23, 2017 at 6:09 PM, Lorenzo Paulatto <span dir="ltr"><<a href="mailto:paulatz@gmail.com" target="_blank">paulatz@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF"><span>
On 21/10/17 12:59, Madhurya Chandel wrote:<br>
<blockquote type="cite">
<div dir="ltr">
<div>
<div>
<div>Respected QE Users<br>
<br>
</div>
1)I have a doubt that how to choose the number of K point
for band structure calculation using Xcysden K path
selection?<br>
</div>
</div>
</div>
</blockquote>
<br>
</span><p>Hello,</p>
<p>I also recommend trying the seekpath online tool
<a class="m_2980855189000185005m_286222230229357078moz-txt-link-rfc2396E" href="http://materialscloud.org/tools/seekpath/input_structure/" target="_blank"><http://materialscloud.org/too<wbr>ls/seekpath/input_structure/></a>,
it is a bit easier than xcrysden to use for this task, as it also
suggests a possible choice of path. The number of points is free,
but you have to take it large enough that the bands look smooth
and not jagged. Also the continuity analysis done by bands.x may
not work if too few points are present. Note that if you use the
tpiba_b or crystal_b format for the points, you only need to
specify the path high-symmetry turning points, and the number of
k-points in between (check the manual)<br>
</p><span>
<blockquote type="cite">
<div dir="ltr">
<div>2) while doing the band structure calculation how to chose
Fermi energy (= eV), deltaE and reference energy? Do these
values affect the band structure plot?<br>
</div>
</div>
</blockquote>
<br></span>
They do not, it is just a rigid shift. It is customary to shift the
bands so that the Fermi energy is at zero. Of course, if your
material is an insulator there is not Fermi energy, if you have
empty bands you can take it in the middle of the gap (average of
highest occupied and lowest unoccupied energy levels). All these
values are printed at the end of any SCF and NSCF (not BANDS)
calculation, check the output file.<br>
<br>
hope this helps<span><br>
<br>
<blockquote type="cite">
<div dir="ltr">
<div><br>
</div>
Thanking you<br>
<div>
<div>
<div>
<div><br>
</div>
<div>With regards<br>
</div>
<div>
<div class="m_2980855189000185005m_286222230229357078gmail_signature">
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<p style="margin:0px 0px 0.0001pt"><span style="font-size:10pt"><b><font face="arial, helvetica,
sans-serif">Madhurya Chandel</font></b></span></p>
<font face="arial, helvetica,
sans-serif"><b>Research Scholar <br>
</b></font></div>
<div><font face="arial, helvetica,
sans-serif"><b>Department of
Chemistry <br>
</b></font></div>
<div><font face="arial, helvetica,
sans-serif"><b>BITS PILANI, GOA
campus<br>
</b></font></div>
<div dir="ltr">
<p style="margin:0px 0px 0.0001pt"><b><font face="arial, helvetica,
sans-serif"><a href="tel:+91%2075075%2046773" value="+917507546773" target="_blank">+91-7507546773</a></font></b></p>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<br>
<fieldset class="m_2980855189000185005m_286222230229357078mimeAttachmentHeader"></fieldset>
<br>
<pre>______________________________<wbr>_________________
Pw_forum mailing list
<a class="m_2980855189000185005m_286222230229357078moz-txt-link-abbreviated" href="mailto:Pw_forum@pwscf.org" target="_blank">Pw_forum@pwscf.org</a>
<a class="m_2980855189000185005m_286222230229357078moz-txt-link-freetext" href="http://pwscf.org/mailman/listinfo/pw_forum" target="_blank">http://pwscf.org/mailman/listi<wbr>nfo/pw_forum</a></pre>
</blockquote>
<br><span class="HOEnZb"><font color="#888888">
</font></span></span><span class="HOEnZb"><font color="#888888"><span class="m_2980855189000185005HOEnZb"><font color="#888888"><pre class="m_2980855189000185005m_286222230229357078moz-signature" cols="72">--
Lorenzo Paulatto - Paris</pre>
</font></span></font></span></div><span class="HOEnZb"><font color="#888888">
<br>______________________________<wbr>_________________<br>
Pw_forum mailing list<br>
<a href="mailto:Pw_forum@pwscf.org" target="_blank">Pw_forum@pwscf.org</a><br>
<a href="http://pwscf.org/mailman/listinfo/pw_forum" rel="noreferrer" target="_blank">http://pwscf.org/mailman/listi<wbr>nfo/pw_forum</a><br></font></span></blockquote></div><span class="HOEnZb"><font color="#888888"><br><br clear="all"><br>-- <br><div class="m_2980855189000185005gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><p style="margin:0px 0px 0.0001pt"><span style="font-size:10pt"><b><font face="arial, helvetica, sans-serif">Madhurya Chandel</font></b></span></p><font face="arial, helvetica, sans-serif"><b>Research Scholar <br></b></font></div><div><font face="arial, helvetica, sans-serif"><b>Department of Chemistry <br></b></font></div><div><font face="arial, helvetica, sans-serif"><b>BITS PILANI, GOA campus<br></b></font></div><div dir="ltr"><p style="margin:0px 0px 0.0001pt"><b><font face="arial, helvetica, sans-serif"><a href="tel:+91%2075075%2046773" value="+917507546773" target="_blank">+91-7507546773</a></font></b></p></div></div></div></div></div></div></div></div></div></div>
</font></span></div>
<br>______________________________<wbr>_________________<br>
Pw_forum mailing list<br>
<a href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</a><br>
<a href="http://pwscf.org/mailman/listinfo/pw_forum" rel="noreferrer" target="_blank">http://pwscf.org/mailman/<wbr>listinfo/pw_forum</a><br></blockquote></div><br></div>