region command and atom coordinates

I have a pretty basic question. When we specify region bounds initially and then add velocity/thermostat to equilibrate the system, does the region change according to the minor changes in the atom coordinates?

Thanks

I have a pretty basic question. When we specify region bounds initially and then add velocity/thermostat to equilibrate the system, does the region change according to the minor changes in the atom coordinates?

Why should a region know or care about atom coordinates?

Okay. I thought so too so this brings me to my original question. I am trying to anneal a graphene structure, 4 layers thick. I am attaching a part of the script here

#-----------------------EQUILIBRATE SYSTEM---------------------------
timestep 0.25

thermo 250
compute gra_temp g_upper temp
thermo_style custom step temp c_gra_temp

fix freeze base setforce 0.0 0.0 0.0

velocity all create 300.0 30102015 dist gaussian
velocity base set 0.0 0.0 0.0 units box

dump equi all atom ${dump} result_equi.lammpstrj

fix ensemble g_upper npt temp 300.0 300.0 10.0 iso 1.0 1.0 100.0
run 48000

unfix ensemble
fix ensemble g_upper npt temp 300.0 1000.0 10.0 iso 1.0 1.0 100.0
run 76000

unfix ensemble
fix ensemble g_upper npt temp 1000.0 300.0 10.0 iso 1.0 1.0 100.0
run 76000

unfix ensemble

undump equi

write_restart restart.mpiio

I am monitoring the upper 3 layers temperature through the compute command. When I output the information, though initially the Tstart and Tstop are set to 300 K (for the group g_upper), its temperature is equilibration around 400 K, but the entire system’s temperature is around 300 K.

Regions in LAMMPS are just geometric entities,

they have nothing to do with atoms being inside/outside them.

Groups are normally static. So if you assign atoms

to a group based on what region they are in, those

atoms will remain in that group no matter where they

move afterwards, e.g. even if they move outside

the region.

Steve