Dear all,
I am trying to model semicrystalline polymer, which has two crystalline region with amorphous region between them. I want my crystalline regions to behave as a single group and amorphous as other group. So, I have separated them using group command.
During the minimization and equilibration process using lammps, the atoms in the crystalline region should move as a whole instead of individual atoms. That is the crystalline region should follow rigid body motion.
I have tried using fix rigid but on viewing the trajectory, the atoms in the crystalline regions move individually instead as a group. I am not sure whether I can use fix rigid to attain the above motion.
Anyone could please help me out.
Here is the script,
region 1 block -57 23 -235 -115 0 55# crystalline
region 2 block -57 23 120 235 0 55# crystalline
region 3 block -57 23 -115 120 0 55# amorphous
region crystallite union 2 1 2
group amor region 3
group crys1 region crystallite
fix 10 crys1 rigid single
minimization
dump 2 all dcd 100 dump_for_min.dcd
dump_modify 2 unwrap yes
thermo 10
thermo_style custom step pe press vol etotal
min_style cg
minimize 1e-25 0.0 1000000 100000000000
print “MINIMIZATION DONE”
undump 2
write_data aftermin.txt
Thank you,