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+====== Should I use MPI or OpenMP or both? ======
+The entire CP2K code is MPI parallelized. Some additional loops are also OpenMP parallelized.
+You should therefore first take advantage of the MPI parallelization.
+However, running one MPI-rank per CPU-core will probably lead to memory shortage.
+At this point, OpenMP threads can be used to utilized all CPU-cores without the large memory-footprint of a MPI-process.
+The optimal ratio between MPI-ranks and OpenMP-threads depends on the kind of simulation you run.
+Do your own benchmarks! A ratio of two threads per rank is usually a good point to start.