# Error: X particles communicated to PME rank N

**URL:** <https://gromacs.bioexcel.eu/t/error-x-particles-communicated-to-pme-rank-n/3114>\
**Category:** User discussions\
**Tags:** mdrun, mdrun-crash\
**Created:** [November 9, 2021, 4:18pm UTC](https://gromacs.bioexcel.eu/t/error-x-particles-communicated-to-pme-rank-n/3114 "2021-11-09T16:18:43Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![David\_SB](https://avatars.discourse-cdn.com/v4/letter/d/a698b9/32.png) [@David\_SB](https://gromacs.bioexcel.eu/u/David_SB)\
**Post date:** [November 9, 2021, 4:18pm UTC](https://gromacs.bioexcel.eu/t/error-x-particles-communicated-to-pme-rank-n/3114/1 "2021-11-09T16:18:43Z")

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GROMACS version: 2020  
GROMACS modification: No

Dear all,  
I’m currently trying to extend my simulations of a peptide from a checkpoint by using _mpirun gmx\_mpi mdrun_ and I’m getting the following error:

_22 particles communicated to PME rank 5 are more than 2/3 times the cut-off_  
_out of the domain decomposition cell of their charge group in dimension x._  
_This usually means that your system is not well equilibrated._

This error has been reported previously in this forum with different number of particles or rank but it doesn’t have a clear solution yet (or at least I couldn’t find it).

The most common answer is that systems are not well equilibrated or related (as it mentions the error itself), but I don’t really think the error is related to this. Rather it seems to me that it is related to the parallelization and domain decomposition. On one hand, these are continuation runs of a system that had already run for one microsecond; also, I am able to run the simulations with only 1 processor

Thank you for your help!  
David

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<div class="post-metadata">

**Author:** ![David\_SB](https://avatars.discourse-cdn.com/v4/letter/d/a698b9/32.png) [@David\_SB](https://gromacs.bioexcel.eu/u/David_SB)\
**Post date:** [November 16, 2021, 11:24am UTC](https://gromacs.bioexcel.eu/t/error-x-particles-communicated-to-pme-rank-n/3114/2 "2021-11-16T11:24:06Z")

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Dear all,  
I’ve just been able to solve the error. When sending the calculations a more recent version of GROMACS was being loaded (2020) while original calculations were done in an older version (2018).