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<p class="MsoNormal">Dear all,<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black">I encountered a problem when trying add a extra term rho_extra(G) into hartree energy calculation (which is done by subroutine v_h in PW/src/v_of_rho.f90). Here rho(G) means density of charge in
G space, which is generated from rho(r) by doing FFT.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Thus, I need to transfer my known rho_extra(r) (extra charge distribution needed) to corresponding rho(G) by doing FFT with hand, the problem is, I have no idea with the standard of FFT set by
Quantum Espresso. <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black">It is important to find how to properly get the rho(G) from rho(r) in the same way as QE do.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black">For example, how does Quantum Espresso set the normalization factor for FFT in a supercelll with volume=V? (It could be put into rho (G) as 1/V, or into rho(r) as 1/V, or into both rho(g) and
rho(r) as 1/sqrt(V)).<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black">I will appreciate if you can offer any help.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black"> <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Thanks a lot !<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Best,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Yue Yu<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt;line-height:14.7pt;background:white">
<span style="font-size:10.5pt;font-family:Courier;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal" style="line-height:14.7pt;background:white"><span style="font-size:10.5pt;font-family:Courier;color:black">========================================<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Yue Yu<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Ph. D student<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black">Department of Physics, University of Florida<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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