[gmx-users] gmx make_ndx - separating pulling groups by fragments

[vprytkov]

Hello! I'm trying to conduct a pulling simulation with two identical 
proteins and centers of mass distance being the reaction coordinate. 
They are distinguished by fragment index in vmd (0 and 1), but the 
residues in the .gro file run from 1 to 178 and again from 1 to 178. How 
to I used make_ndx command to create an index file for the pulling 
simulation?
Thank you!