I have assigned a set of atoms to a particular group and defined a region of space in my input script. Originally, all the atoms from the group are outside the region. When I run a simulation, some atoms from the group may enter the region. I want to determine the time-step at which any atom from the group first enters the region. Is it possible to do this without outputting the number of atoms in the region every time-step? I have managed to accomplish this using fix halt but I am wondering if there is an easier way without stopping the simulation.
***DISCLAIMER*** The sender of this email is an alumnus of National University of Singapore (NUS). Kindly note that NUS is not responsible for the contents of this email, and views and opinions expressed are solely the sender's.