Dear sir,<br> and the possibility about calculation of electro-optic properties with electric filed in phonon code ????? Please advice. <br>Thanks<br>Dev<br><br><div class="gmail_quote">On Mon, Sep 28, 2009 at 1:30 PM, Paolo Giannozzi <span dir="ltr"><<a href="mailto:giannozz@democritos.it">giannozz@democritos.it</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="im">Emine Kucukbenli wrote:<br>
<br>
> It is clearly stated there that "the non-local contribution due to the<br>
> pseudopotential is neglected. Actually the correction to the matrix<br>
> element that take into account the non-local part of the Hamiltonian<br>
> is not implemented."<br>
> So to develop the code for USPP you need to find a way to calculate &<br>
> add these corrections, I guess.<br>
<br>
</div>it is not sufficient. For norm-conserving PP, there is a nonlocal<br>
contribution to the matrix elements <\psi_i| r | \psi_j> (i /= j)<br>
that is not accounted for in epsilon.x . This is the meaning of<br>
the above statement.<br>
<br>
For USPP, additional terms have to be added, since only the smooth<br>
term of |\psi_i> (the one expanded into plane waves) is available.<br>
<br>
The correct calculation of matrix elements is actually performed<br>
in the phonon code and could be in principle imported into<br>
epsilon.f90.<br>
<br>
P.<br>
<font color="#888888">--<br>
Paolo Giannozzi, Democritos and University of Udine, Italy<br>
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