<div dir="ltr">Hi Valentin<br><br>I have added a keyword SEED in the section &SUBSYS. That SEED keyword expects exactly 1 or 6 valid integer values as argument which define the initial seed(3,2) array for the Wiener process (a single argument value is replicated).<br>Please, check and provide feedback.<br><br>Matthias<br><br>On Friday, 14 October 2016 12:18:52 UTC+2, Ole Schütt  wrote:<blockquote class="gmail_quote" style="margin: 0;margin-left: 0.8ex;border-left: 1px #ccc solid;padding-left: 1ex;">Hi Valentin,
<br>
<br>I opened a ticket at sourceforge for this.
<br>
<br>-Ole
<br>
<br>On 2016-10-13 19:19, Valentin wrote:
<br>> Hi,
<br>> 
<br>> my post concerns the problem that the value of the global seed does
<br>> not affect the initialization of the parallel random number generator
<br>> that is used for the Wiener process in the Langevin ensemble. For cp2k
<br>> version 4.1_, _the first particle-specific seed is set in line 95 of
<br>> _motion/wiener_process.F_ by calling _next_rng_seed()_ without
<br>> arguments, thus resulting in 12345.0.
<br>> 
<br>> I observed (using version 2.4) that setups that differed only in their
<br>> initial velocities showed strong correlations among each other in
<br>> their dynamics after a short time, which I would attribute to the
<br>> noise term being de facto not random.
<br>> 
<br>> A similar issue for MC calculations has been posted in this forum
<br>> before (subject "Seed numbers bug in MC") and the problem has been
<br>> solved in version 4.1 by specifying
<br>> _last_rng_stream=force_env_1%<wbr>globenv%gaussian_rng_stream_. Could you
<br>> fix this problem for the Wiener process as well?
<br>> 
<br>> Thanks,
<br>> Valentin
<br>> 
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