calculation of total interaction energy between two group of atoms with respect to distance

It is showing the following error.
ERROR: Illegal compute group/group command (…/compute_group_group.cpp:104)

With regards
Shamimul Ahsan

which means there is an error in one of your compute group/group commands. if you run with -echo screen you can see exactly which one.

have a careful look and you should see that you have a typo.

axel.