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Band gap is always a matter of what quantity you are looking for:
electronic conductivity, optical propeties ...<br>
<br>
In the present case the band gap obtained in the band structure is
the fundamental band gap (direct or indirect). <br>
The band gap given by the DOS is certainly smaller, because you do
not have the information related to the energy dispersion of the
bands. <br>
<br>
You should also do the difference between the optical band gap and
the fundamental band gap for instance. <br>
<br>
So what is the right value? From a theoretical point of view the
right value (the more accurate) is the fundamental band gap.
However, you must think about the fact that a band gap is a useful
quantity if it is related to a property! <br>
If you are looking to optical properties, the best value will be
obtained from the dielectric function. <br>
If you are looking at electronic properties ... band structure is
well-suited ...<br>
<br>
Regards<br>
<br>
Xavier<br>
<br>
<br>
Le 17/10/2012 17:26, ben amara imen a écrit : <br>
<blockquote
cite="mid:CACAZvnpSkvaGB4rwXGuSB7sApF96RS4uAW-AGdmPm-HDF7N7tw@mail.gmail.com"
type="cite">
<div dir="ltr">Hello !
<div><br>
</div>
<div> I want to determine the gap's value for my compound. So, I
have calculated DOS and structure bands SB. In my case, DOS
gives a value , SB gives me another different value and I
have found a another value in case.SCf2 . So I have a three
different value of gap !!!!</div>
<div><br>
</div>
<div>I want to know the singnification of each value (given by
DOS; SB and case.SC2 ) and what's the right value??? I mean
what the right value that I have to choose</div>
<div><br>
</div>
<div>Can someone helps me please!</div>
<div> And thanks in advance </div>
</div>
<br>
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<br>
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