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<p>Not sure that it will help or not, but I thought it might be
worth mentioning.</p>
<p>For the WIENncm code, I tried locating the WIEN2k version that it
was developed from. In December 2023, I had traced it back to
being about WIEN2k 6.4 as seen in the post at [1].<br>
</p>
<p>On the WIEN2k updates page [2] under VERSION_12.1: 22.7.2012,
there is:</p>
<p>SRC_lapw1: important fix for blocksize when using <b>recent </b>(12.x)<b>
versions of mkl</b> (dscgst.F, zhcgst.F) leading to core dumps</p>
<p>We were experiencing lapw1 segmentation faulting particularly bad
with the newer Intel compilers/mkl until that was fixed. You
should find the fix described in the post at [3]. Though, it
would be hard to know if this would be the only change possibly
needed as you can see other changes were made to lapw1 between
WIEN2k 6.4 and 23.2.<br>
</p>
[1]
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg22933.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg22933.html</a><br>
[2] <a class="moz-txt-link-freetext" href="http://www.wien2k.at/reg_user/updates/">http://www.wien2k.at/reg_user/updates/</a><br>
[3]
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg07567.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg07567.html</a><br>
<p>Kind Regards,</p>
Gavin<br>
WIEN2k user<br>
<p><br>
</p>
<div class="moz-cite-prefix">On 7/8/2024 9:15 AM, Fecher, Gerhard
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:0b8d7778a9ec43579f5a9c17f0bec84f@uni-mainz.de">
<pre class="moz-quote-pre" wrap="">Hallo Peter or anyone else who has an idea,
I have a "problem" in the NCM Version, I need to reduce RKmax down to 4.0, otherwise I receive segmentation faults from lapw1.
(probably during allocation or reallocation in modules.F, INIT_MATRICES)
I needed to set NMATMAX = 128 000 that RKmax=4.0 works, but 5.0 crashes already for a 14 atom system.
(Note in the regular (not ncm) 23.2 version the systems run with NMATMAX = 29 000 at RKmax=7.0)
How can I determine easily how large NMATMAX should be for a given matrix size and memory?
The manual tells: "(..., should be chosen according to the memory of your hardware, see chapter 11.2.3!)
As mentioned for the regular version in 11.2.3 NMATMAX is reduced by sqrt(2), I am not shure whether or not this holds in ncm that uses only lapw1c.
As seen below a matrix size of 840 works at NKMAX=128000 in the NCM version, whreas 1100 is already too large.
In the regular version NKMAX=29000 works for a matric size of aboz 2400 (most probably also for much larger size).
Or is there any other possibility to use larger RKmax, maybe by changing something in the code.
PS.: Just for info, I have between 3 and 4GB RAM per core available on each node.
PSS: Examples: for pure Fe, rkmax=8.0 works (2 atoms in the conventional cell),
for a system with 14 atoms (Sr2FeO4) I need to lower RKmax to 4.0 because 4.5 crashes already
whereas the regular lapw1 runs with at least 3 times larger matrix size at a quarter of NKMAX.
Some numbers for the 14 atom case
* Regular Version: NKMAX = 29000
RKmax=7.0 MATRIX SIZE 1606 LOs: 96 RKM= 6.99 (has inversion, not complex, lapw1)
RKmax=8.0 MATRIX SIZE 2388 LOs: 96 RKM= 8.00
* NCM Version: NKMAX = 128000
RKmax=4.0: MATRIX SIZE 840 LOs: 196 RKM= 3.98 has NO problem (always complex, lapw1c of NCM)
RKmax=4.5: MATRIX SIZE 1100 LOs: 196 RKM= 4.44 crashes for sequential and k-parallel
RKmax=5.0: MATRIX SIZE 1408 LOs: 196 RKM= 4.99 crashes
for comparison pure Fe (NCM Version mit NKMAX = 128000) runs with RKmax up to 8.0 without problems
RKmax=5.0: MATRIX SIZE 104 in the ncm Version (conventional cell, 2 atoms)
RKmax=6.0: MATRIX SIZE 118 LOs: 52 RKM= 5.42
RKmax=7.0: MATRIX SIZE 214
RKmax=8.0: MATRIX SIZE 238 LOs: 52 RKM= 7.66
Ciao
Gerhard
</pre>
</blockquote>
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