The attached dataset can be used in order to evidence an issue in `check_assign_interactions_atom()` that was introduced during a revamp in gromacs/gromacs@c507ae4d3f4b0d516e53896dac35a52911a8a44b The issue only occurs with `gmx_mpi` when more that one MPI task is used. The issue affects both the `master` and `release-2020` branches. In order to reproduce the issue : ``` # preprocess the data gmx grompp -f mdp/equil_nvt_gpu.mdp -c em.gro -r em.gro -p topol_fin.top -n index.ndx -o nvt.tpr -maxwarn 2 # run in parallel mpiexec -n 2 gmx_mpi mdrun -deffnm benchmark -s nvt.tpr -ntomp 1 ``` This dataset can also be used to evidence the issue described in https://gitlab.com/gromacs/gromacs/-/issues/3626 (and that has already been fixed) and the issue whose fix is discussed at https://gitlab.com/gromacs/gromacs/-/merge_requests/448