Small system - mpi error -I couldn't start em job

gromacs 2022+cp2k interface

My system is small but how I can fix this mpi error. I couldn’t start em job

Command line:
gmx_cp2k mdrun -v -deffnm em

Compiled SIMD: AVX_256, but for this host/run AVX_512 might be better (see
Reading file em.tpr, VERSION 2022 (double precision)

Program: gmx mdrun, version 2022
Source file: src/gromacs/domdec/domdec.cpp (line 2232)
MPI rank: 0 (out of 28)

Fatal error:
There is no domain decomposition for 28 ranks that is compatible with the
given box and a minimum cell size of 1.81394 nm
Change the number of ranks or mdrun option -rdd or -dds
Look in the log file for details on the domain decomposition

For more information and tips for troubleshooting, please check the GROMACS
website at Errors - Gromacs

Primary job terminated normally, but 1 process returned
a non-zero exit code. Per user-direction, the job has been aborted.

mpirun detected that one or more processes exited with non-zero status, thus causing
the job to be terminated. The first process to do so was:

Process name: [[1062,1],2]
Exit code: 1

Use fewer processors. Your system is too small to divide over 28 ranks.

ok thank you!