Dear all I am running cascade simulation of bulk vanadium lattice. I am getting the lost atoms errors. I have read about this error in the lammps archives and learnt that main reason for this error is large time step, but I reduced my time step as low as 10e-6 ps even then the same error persisted. >From dump snapshots visualised in VMD I realized that atoms are lost when the pka approaches its immediate neighbor and at that point PE and KE also shoot up. Inspite of these observations I could not rectify the error. Below is my input file. Any help in this regard would be much helpful.
cascade simulation of bulk V lattice
units metal
atom_style atomic
neighbor 1 bin
neigh_modify delay 1
lattice bcc 3.03
region box block 0 50 0 50 0 50
boundary p p p
create_box 1 box
create_atoms 1 box
#creating regions
region rallatoms block INF INF INF INF INF INF
region rinterior block 2 48 2 48 2 INF
region rexterior block 2 48 2 48 2 INF side out
region rpka sphere 30.3 30.3 30.3 0.4
#define potential
pair_style eam/fs
pair_coeff * * VFe_mm.eam.fs V
#creating groups
group interior region rinterior
group exterior region rexterior
group pka region rpka
#creating fixes
fix 1 all nve
fix 2 exterior temp/rescale 1 300 300 0.5 1.0 region rexterior
fix 3 interior temp/rescale 1 300 300 0.5 1.0 region rinterior
#equilibration of the system
timestep 0.001
thermo 100
thermo_style custom step temp pe etotal press
run 1000
#remove scaling from the interior and continue to equilibrate
unfix 3
run 1000
#set pka velocity correspond to 10kev in [135] direction
set group pka vx 232 vy 697 vz 1200
#initial phase of collision
timestep 0.000001
thermo 100
dump mydump all xyz 100 dump.xyz
run 20000
#intermediate phase of collision
timestep 0.0001
run 10000