[lammps-users] lammps,ATC,laser ablation

respected sir/madam
I am trying to do laser ablation of copper using the ATC package but I have faced some difficulties like mesh creation,boundary conditions and where I add the laser source term in the input file, here I have attached the input file.

lasersuc.in (1.81 KB)

It will be difficult for anybody to help you if you do not explain what your difficulties are and ask specific questions.
Please see the mailing list guidelines for some advice on this https://lammps.org/guidelines.html

I want to do laser ablation/spallation of copper using the ATC package
I read about the fix atc command in lammps manual but I don’t understand about fix atc mesh creation, faceset etc.

here is my code and questions
units metal
variable inf equal 1000

atom_style atomic

lattice fcc 3.62 origin 0.25 0.25 0.25
boundary p p s
region mdRegion block 0 5 0 5 5 80
region feRegion block 0 5 0 5 0 100
Q1. Is the size of the block region correct? When I change 100 to any number, no mesh creation occurs. How are they related to each other?

create_box 1 mdRegion
create_atoms 1 region mdRegion

pair_style eam/alloy
pair_coeff * * Cu.eam.alloy Cu
neighbor 0.3 bin
neigh_modify every 10 delay 0 check yes
mass 1 63.546
group internal region mdRegion
dump 1 all atom 10 manash.dump
timestep 0.001
thermo 100
velocity internal create 300 1234156
fix 1 all nvt temp 300 300 0.01
run 10000
unfix 1

thermo 50

fix a temperature

fix AtC internal atc two_temperature Cu_ttm.mat
fix_modify AtC mesh create 1 1 20 feRegion p p f
Q2. When I change the number of elements in x from 20 to any number, no mesh creation occurs. Why?
What does mesh create exactly mean?

fix_modify AtC mesh create_faceset bndy box -inf inf -inf inf 5 80

Q3. What does mesh create_faceset bndy box mean?

fix_modify AtC control thermal flux
fix_modify AtC initial temperature all 300
fix_modify AtC initial electron_temperature all 300


fix_modify AtC mesh create_nodeset bottom -INF INF -INF INF 0 0
fix_modify AtC fix temperature bottom 300
fix_modify AtC fix_flux electron_temperature bndy **
run 4000

Q4. from the ttm md model equation the laser source term S(z,t) (W/cm3) is calculated using fluence of the laser,
pulse duration and optical penetration depth .My question is in the input file where I add laser energy term if I calculate

laser source term (S(z,t)) ?


fix_modify AtC unfix_flux electron_temperature bndy **
run 5000

How much experience do you have with MD simulations of metals in general?
Your input looks like you took pieces from different input examples and pasted them together.

Most of your questions should be self-explanatory from the LAMMPS manual or from understanding how AtC combines a FE solver with MD.
I am particularly confused why you are asking about creating a mesh since that is crucial to the method.

For the more specific details, I cannot help you. You either have to look through the sourcecode and try to relate it to the relevant AtC publications, or contact the AtC developers. Mind you, this project has not been under active development for many years, so it may take some time to get a response…

Thanks a lot.