Dear Lammpsers,
I am writing to inquire about using a proper fix command in Phase(5) of my input file .
As per this file input file, after reaching the initial equilibrium condition of the particle & substrate at 300 K. the particle(cluster of atoms) impacted to the substrate using fix npt command and velocity commands.
But, the problem is that it is expected when particle impacts to the substrate, its temperature rapidly increases to a maximum with respect to the time and then decreases. But, I cannot see this trend. Rather, temperature just increases in the thermo results. So, I think I should modify this command.
So, any help on this matter is highly appreciated.
Best regards,
Bahman Daneshian
#Phase 1 ------------------------------------------Simulation main setup----------------------------------
dimension 3
units metal
atom_style charge
boundary p p p
#simulation box
region box block 0 90 0 4 -30 70
create_box 2 box
lattice custom 1 a1 4.59373 0.00000 0.00000 a2 0.0000 4.59373 0.00000 a3 0.00000 0.00000 2.95812 &
basis 0.0000 0.0000 0.0000 &
basis 0.5000 0.5000 0.5000 &
basis 0.3053 0.3053 0.0000 &
basis 0.6947 0.6947 0.0000 &
basis 0.8053 0.1947 0.5000 &
basis 0.1947 0.8053 0.5000
mass 1 16.00
mass 2 47.86
#particle
region particle cylinder y 45 40 20 0 4 units box
create_atoms 2 region particle &
basis 1 1 &
basis 2 1 &
basis 3 2 &
basis 4 2 &
basis 5 2 &
basis 6 2
group particle region particle
#substrate
region substrate block 0 90 0 4 -20 10 units box
create_atoms 2 region substrate &
basis 1 1 &
basis 2 1 &
basis 3 2 &
basis 4 2 &
basis 5 2 &
basis 6 2
group substrate region substrate
#substrate_bottom
region substrate_bottom block 0 90 0 4 -30 -20 units box
create_atoms 2 region substrate_bottom &
basis 1 1 &
basis 2 1 &
basis 3 2 &
basis 4 2 &
basis 5 2 &
basis 6 2
group substrate_bottom region substrate_bottom
group model union particle substrate
set type 1 charge 2.196
set type 2 charge -1.098
#–Phase 2----------------------------------------Buckingham Potential-----------------------------------------------
Potential
buck/coul/long 2.5
pair_style buck/coul/cut 2.5
pair_coeff 1 1 31120 0.154 5.250
pair_coeff 1 2 16958 0.194 12.590
pair_coeff 2 2 11783 0.234 30.220
#kspace_style ewald 1.0e-4
#—Phase 3----------------------------------------Compute—how can I monitor Vparticle!!! ------------------------
compute temp_particle_1 all temp/region particle
compute temp_particle_2 particle temp/com
compute temp_substrate all temp/region substrate
#----Phase 4-------------------------------------Initial Equilibration at 300K ----------------------------------------
reset_timestep 0
timestep 0.001
velocity model create 300 12345 mom yes rot no
fix 1 particle nvt temp 300.0 300.0 0.01
fix 2 substrate nvt temp 300.0 300.0 0.01
thermo 100
thermo_style custom step c_temp_particle_1 c_temp_substrate
dump 1 all image 200 image..png type type adiam 1.5 axes yes 0.8 0.02 zoom 2.0 view 80 -90
dump_modify 1 backcolor white boxcolor white acolor 12 blue/red/orange/green/cyan/aqua/yellow/red
run 1000
unfix 1
unfix 2
#----Phase 5---------------------------------------Particle Impact at the room temperature --------------------
reset_timestep 0
timestep 0.001
fix 3 model npt temp 300 300 1 iso 0 0 100
fix 4 substrate temp/rescale 600 300 300 1.0 1.0
thermo 100
thermo_style custom step c_temp_particle_2 c_temp_substrate
velocity particle set 0 0 -8.0 sum no
dump 2 all image 200 image..png type type adiam 1.5 axes yes 0.8 0.02 zoom 2.0 view 80 -90
dump_modify 2 backcolor white boxcolor white acolor 12 blue/red/orange/green/cyan/aqua/yellow/red
run 5000
