[CP2K-user] [CP2K:13022] Wanting to get synchronized trajectories

[Noam Bernstein]

If you’re using an algorithm with a random component, e.g. Langevin, you need to set the same &GLOBAL&SEED. 

Floating point math operations are not associative, so you can also try &GLOBAL&BLACS_REPEATABLE, which tries to make the parallel reduction repeatable. However, this can only help if the architecture and number of MPI tasks is identical. But I’m not sure if that flag controls all of the possibly non deterministic operations. 

   Noam