Hi all:
I am trying to apply a force to atoms belonging to a specified region. My input file is as follows:
#Bicrystal: dynamics
read_restart restart.sigma5
kspace_style ewald 1.0e-4
velocity all create 1500.0 82986 dist gaussian mom no
#Calcula la fuerza sobre cada atomo de itrio
#variable f_x1 atom 3.1*(x-10.26)/sqrt((x-10.26)(x-10.26)+(y-12.17)(y-12.17)+(z-16.2325)(z-16.2325))
#variable f_y1 atom 3.1(y-12.17)/sqrt((x-10.26)(x-10.26)+(y-12.17)(y-12.17)+(z-16.2325)(z-16.2325))
variable f_z1 atom 2.5(z-16.2325)/sqrt((x-10.26)(x-10.26)+(y-12.17)(y-12.17)+(z-16.2325)(z-16.2325))
#variable f_x2 atom 3.1(x-10.26)/sqrt((x-10.26)(x-10.26)+(y-12.17)(y-12.17)+(z-48.6975)(z-48.6975))
#variable f_y2 atom 3.1(y-12.17)/sqrt((x-10.26)(x-10.26)+(y-12.17)(y-12.17)+(z-48.6975)(z-48.6975))
variable f_z2 atom 2.5(z-48.6975)/sqrt((x-10.26)(x-10.26)+(y-12.17)(y-12.17)+(z-48.6975)*(z-48.6975))
fix fuerza_1 yttrium_1 addforce 0.0 0.0 v_f_z1 region grain_1
fix fuerza_2 yttrium_2 addforce 0.0 0.0 v_f_z2 region grain_2
…
Both grain_1 and grain_2 regions where defined in the minimization script which I launched to get the restart file. However, when I launch LAMMPS I get the message:
ERROR: Fix addforce region ID does not exist.
Any help?
Thanks in advance!!
Juanjo