[Pw_forum] shift of energy

[Eyvaz Isaev]

Hi, 

 
>The bandgap of 8-atoms is around 10-12 eV, 
>but that of 72-atom is around 5-7 eV.

This is unbelievable, as SiC is an indirect band gap semiconductor and 
the bandgap is around (2.5 - 3)eV depending on crystal modification 
(3C-SiC, 2H-SiC; 4H-SiC; 6H-SiC, etc.). 
See http://www.matprop.ru/SiC_bandstr

So, check carefully your input/output files.

Bests,
Eyvaz.

-------------------------------------------------------------------
Prof. Eyvaz Isaev, 
Department of Physics, Chemistry, and Biology (IFM), Linkoping University, 
Sweden 

Theoretical Physics Department, Moscow State Institute of Steel & Alloys, 
Russia, 

isaev at ifm.liu.se, eyvaz_isaev at yahoo.com




________________________________
From: pari shok <parishok at gmail.com>
To: pw_forum at pwscf.org
Sent: Sun, April 3, 2011 1:34:51 AM
Subject: [Pw_forum] shift of energy


Dear Paolo,
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.
Would you please help me to understand this shift.
 Thanks again.
P Shok
UMD
On Apr 1, 2011, at 21:36 , pari shok wrote:

> The DOS of 72-atom SiC (supercell) shows a shift of energy.

a shift with respect to what?
---
Paolo Giannozzi, Dept of Chemistry&Physics&Environment,
 Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222



      
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