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<blockquote
cite="mid:2035900646.471504.1483878463384@mail.yahoo.com"
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<div id="yui_3_16_0_ym19_1_1483877874491_4409" dir="ltr">I just
want to know why fftw and mpich should be installed before
installing wien2k12.</div>
<div dir="ltr" id="yui_3_16_0_ym19_1_1483877874491_4434">Are
they necessary for doing the calculation parallel?</div>
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<br>
For mpi-parallel calculations, you must have them.<br>
<br>
For serial and k-point parallel calculations, they are not needed.
The non-mpi calculations use WIEN2k's fftpack, but you can
optionally use fftw, which might give some calculation speedup as
described in section 11.1.1 on page 218 of the WIEN2k 16.1
usersguide [
<a class="moz-txt-link-freetext" href="http://susi.theochem.tuwien.ac.at/reg_user/textbooks/usersguide.pdf">http://susi.theochem.tuwien.ac.at/reg_user/textbooks/usersguide.pdf</a>
].<br>
<br>
The fftw is needed before the WIEN2k install so that its header and
library files can be compiled and linked together with the WIEN2k
code.<br>
<br>
The mpich is needed before the WIEN2k install so that the
environment, such as bin path, can configured during the WIEN2k
installation.<br>
<br>
<blockquote
cite="mid:2035900646.471504.1483878463384@mail.yahoo.com"
type="cite">
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font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial,
Lucida Grande, sans-serif;font-size:16px">
<div dir="ltr" id="yui_3_16_0_ym19_1_1483877874491_4471">
should I install Mpich and Fftw according to this fact that I
want to do the calculation in a single core?</div>
</div>
</blockquote>
<br>
No, a serial calculation is for a single core and it can be a waste
of time to install them for two cores [
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg03793.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg03793.html</a>
].<br>
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