Lammps Memory Problem

Dear All,

In my Lammps input script I am trying to create many regions ( more than 200k). However, as I observed, memory used by Lammps increases linearly as the regions are being created. And after a certain memory (around 256M), the job is killed by Signal 9 due to Rank 0 on one of the processors. When I reduce the number of processors, I can increase the number of regions that can be generated, but it is still terminated because it cannot reach to total number of regions.

I tried to delete regions after their corresponded union operation. But, even I created new region Ids with union operation. If I delete one of the regions that is created before union operation, create_atoms command gives an error. So I can not delete regions.

How can I manage this linearly increasing memory problem? Should I change something during compilation of Lammps?

I would appreciate if you take your time to help with this issue.