Dump custom compute does not calculate per-atom vector!

Thank you very much Carlos for your comment. You were right! The simulation was fine, just the way that temp was being dumped should be modified. :slight_smile:
I've got also a bit of confusion about the way that dump/compute command work.
In my new input file, I am trying to compute and calculate mean squared displacement of fluid molecules during their diffusion through the rigid solid structure.
However, when trying to run MD, the simulation crashes with the following error:

"ERROR: Dump custom compute does not calculate per-atom vector (dump_custom.cpp:1165)"

Is there any other way of computing/dumping mean squared displacement that I should use instead? Here is also my input file:

Please read the doc pages for compute msd and msd/molecule.
They say what kind of output they produce, and it isn't per-atom
quantities. And read Section 6.15 of the manual which describes
all the different kinds of output and what commands work
with what kind of output.