AIMD simulation: increase of the number of the SCF cycles per MD step after some MD steps

[Max]

Hi Flo, 

I've made tens of additional tests with the FULL_KINETIC preconditioner, 
increasing progressively  the value of the ENERGY_GAP to very large 
values (like 5 Ha). In the best case, this tends only to delay the 
occurence 
of the convergence issue. 

So, for the studied open-shell system, the FULL_ALL preconditioner remains 
the best choice despite its computational cost. I was using an MPI+OMP 
version of  CP2K-2.5.1; switching to the pure MPI version divides the time 
taken by the first SCF cycle by 3~4, and this does more than compensate 
for the increase of the time taken by the next cycles. 

Linking the code to the ELPA2-2013.11.008 library reduces the time taken by 
the first SCF cycle by some additonal and significant 10~14%! 
Unfortunately, 
the MD simulation gets killed after a few hundreds cycle by the OOM killer. 
Granting more memory to each process by decreasing the number of processes 
per node allows to delay the occurence of the problem. This suggests a 
memory 
leak; but, not being familiar with the code, I cannot track it down. I read 
the 
cp_fm_elpa routine in the file src/cp_fm_diag.F, and it seems to me that 
the 
allocated memories are returned at the end of the call to the function, but 
I may 
be wrong. 

If you have time, could you please have a look at this? so as to point me 
to some 
directions ot explore? 

Please note that I've compiled the ELPA2-2013.11.008 library with only the 
generic 
fortran kernels.

Cheers, 
Max

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