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<div class="moz-cite-prefix">On 03/29/2013 05:27 PM, Aaditya
Manjanath wrote:<br>
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I would like to know, what is the purpose/logic of this subroutine,
since I see that this is an essential part in calculating the
dynamical matrices at arbitrary q-points.<br>
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cite="mid:CALcVMZKdB5iKjujb6nsNC2bT215UeZcOmuStB-6NdfXqKejnpg@mail.gmail.com"
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I would be grateful if you could shed some light on this
problem.<br>
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Dear Aaditya,<br>
wsweights does a very simple task in a very complicated way. It
assigns this weights:<br>
1) if a point is inside the Wigner-Seitz cell: weight=1<br>
2) if a point is outside the WS cell: weight=0<br>
3) if a point q is on the border of the WS cell, it finds the number
N of translationally equivalent point q+G (where G is a lattice
vector) that are also on the border of the cell. Than, weight = 1/N<br>
<br>
I.e. if a point is on the surface of the WS cell of a cubic lattice
it'll have weight 1/2, on the vertex of the WS it would be 1/8; the
K point of an hexagonal lattice has weight 1/3 and so on.<br>
<br>
It takes some thought and some time to understand wsweight; if I
remember correctly, Schwarz inequality is used <
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<a
href="http://en.wikipedia.org/wiki/Cauchy%E2%80%93Schwarz_inequality">http://en.wikipedia.org/wiki/Cauchy%E2%80%93Schwarz_inequality></a><br>
<br>
bests<br>
<br>
<br>
<pre class="moz-signature" cols="72">--
Dr. Lorenzo Paulatto
IdR @ IMPMC -- CNRS & Université Paris 6
phone: +33 (0)1 44275 084 / skype: paulatz
www: <a class="moz-txt-link-freetext" href="http://www-int.impmc.upmc.fr/~paulatto/">http://www-int.impmc.upmc.fr/~paulatto/</a>
mail: 23-24/4é16 Boîte courrier 115, 4 place Jussieu 75252 Paris Cédex 05
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