Some questions about scan set up

[matthew-chem97]

Hello there.
I am a PhD student
I need to do a QM/MM scan of a protein (QM=82 atoms, MM=5500 atoms). I shouls use gfn2/gnff setup.
I really appreciate xtb: it' is one of the most useful and user friendly computational software that I' ve used in my life !
However I really need some advices:
1)How much RAM do I need ?
I usually do : OMP_STACKSIZE=4G
And run it with --parallel 4
but doing this the process is killed by out of memory. Any advice to reduce RAM size ?
2)How to print for each step the contribution of E(model,high)
3)If the process is killed, how to restart the scan from the last step ?