Thanks so much prof. Hutter for your reply.
Attached, I provide an example. In the zip file there are two input scripts main_1.inp and main_2.inp which both run MD simulation with interactions evaluated by xTB for a simulation box containing 8 CO2 molecules.
Everything is the same for the two scripts except the size of the simulation box which in main_2 is ca 2.5 times larger in each direction. For these two scripts, each MD step took on my system with 32 cores roughly 0.64 and 11 s, respectively which seems kind of unusual to me.
I am wondering first of all, is it normal that for larger cells which contain exact same particles and default cut-off computations become so slower and are there some ways to avoid it, e.g. if someone need to study a very dilute gas state?
Thanks in advance and best regards,
Amin