<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman,new york,times,serif;font-size:12pt">Hi, <br><div> <pre><font size="4">>The bandgap of 8-atoms is around 10-12 eV, <br>>but that of 72-atom is around 5-7 eV.<br> <br>This is unbelievable, as SiC is an indirect band gap semiconductor and <br>the bandgap is around (2.5 - 3)eV depending on crystal modification <br></font>(3C-SiC, <i>2H</i>-SiC; <i>4H</i>-SiC; <i>6H</i>-SiC, etc.). <br><span>See <a target="_blank" href="http://www.matprop.ru/SiC_bandstr">http://www.matprop.ru/SiC_bandstr</a></span><br><br>So, check carefully your input/output files.<br><br>Bests,<br>Eyvaz.<br><br></pre></div>-------------------------------------------------------------------<br>Prof. Eyvaz Isaev, <br>Department of Physics, Chemistry, and Biology (IFM), Linkoping University, Sweden <br>Theoretical Physics Department, Moscow State Institute of
Steel & Alloys, Russia, <br>isaev@ifm.liu.se, eyvaz_isaev@yahoo.com<div><br></div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><br><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><font face="Tahoma" size="2"><hr size="1"><b><span style="font-weight: bold;">From:</span></b> pari shok <parishok@gmail.com><br><b><span style="font-weight: bold;">To:</span></b> pw_forum@pwscf.org<br><b><span style="font-weight: bold;">Sent:</span></b> Sun, April 3, 2011 1:34:51 AM<br><b><span style="font-weight: bold;">Subject:</span></b> [Pw_forum] shift of energy<br></font><br>
<pre><font size="4">Dear Paolo,<br>DOS of 72-atom SiC shows a shift of energy with respect to 8-atom SiC.The bandgap of 8-atoms is around 10-12 eV, but that of 72-atom is around 5-7 eV.<br>Would you please help me to understand this shift.<br>
Thanks again.<br>P Shok<br>UMD<br>On Apr 1, 2011, at 21:36 , pari shok wrote:<br><br>><i> The DOS of 72-atom SiC (supercell) shows a shift of energy.<br></i><br>a shift with respect to what?<br>---<br>Paolo Giannozzi, Dept of Chemistry&Physics&Environment,<br>
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy<br>Phone +39-0432-558216, fax +39-0432-558222</font><br></pre>
</div></div>
</div><br>
</body></html>