Neighbor command for kMC

LAMMPS LAMMPS General Discussion
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1

I’m trying a kMC simulation to understand interdiffusion around Pd/V interface. I create an interface model whose size is about 60 x 60 x 120 A^3. I want to swap atoms neighbors, so I use “neighbor” command. However, atoms at the center of the models were swapped. It seems likely that “neighbor” command doesn’t work.
Could anyone tell me where the problem is?

---------------input file ---------------------

swap

units metal
dimension 3
boundary p p p
atom_modify map array sort 0 0.0
atom_style atomic
read_data data_000.lmp
variable e equal pe

shell "echo variable rand equal {RANDOM} > rand" include rand variable r equal round(random(18347,434572049,{rand}))

pair_style meam/c
pair_coeff * * …/…/…/library/library.meam Pd V …/…/…/library/PdV.meam Pd V

neighbor 0.0 bin
neigh_modify every 2 delay 2 check yes

variable t equal 873
fix m1 all atom/swap 1 1 $r $t types 1 2

thermo 1
thermo_style custom step temp press pxx pyy pzz lx ly lz etotal pe ke f_m1[1] f_m1[2]
dump 1 all cfg 1 snapshot_*.cfg mass type xs ys zs fx fy fz
dump_modify 1 sort id element Pd V pad 8
run 1000

2

You didn’t study the documentation carefully enough.
Fix atom/swap does what its documentation says it does and that is what you are observing.
Adding a neighbor command doesn’t change that. As its documentation says, using neighbor 0.0 bin will change the neighbor list skin distance from the default value to 0.0 and nothing else.

3

Thank you for replying.

Is there another available command for kMC simulations?

4

I don’t think so. LAMMPS is a molecular dynamics software and not a kMC code.

5

Thank you