lammps/examples/body/in.wall2d

# 2d rounded polygon bodies

variable    r     index 4
variable    steps index 100000
variable    T     index 0.5
variable    P     index 0.1
variable    seed  index 980411

units       lj
dimension   2

atom_style  body rounded/polygon 1 6
atom_modify map array
read_data   data.squares

replicate   $r $r 1

velocity    all create $T ${seed} dist gaussian mom yes rot yes

change_box  all boundary p f p

variable cut_inner  equal 0.5
variable k_n        equal 100
variable k_na       equal 2
variable c_n        equal 0.1
variable c_t        equal 0.1
variable mu         equal 0.1
variable delta_ua   equal 0.5

pair_style body/rounded/polygon ${c_n} ${c_t} ${mu} ${delta_ua} ${cut_inner}
pair_coeff * * ${k_n} ${k_na}

comm_modify vel yes

neighbor     0.5 bin
neigh_modify every 1 delay 0 check yes

timestep     0.001

#fix         1 all nve/body
#fix         1 all nvt/body temp $T $T 1.0
fix          1 all npt/body temp $T $T 1.0 x 0.001 $P 1.0 fixedpoint 0 0 0

fix          2 all enforce2d
fix          3 all wall/body/polygon 2000 50 50 yplane 0.0 48.0

#compute      1 all body/local id 1 2 3
#dump         1 all local 100000 dump.polygon.* index c_1[1] c_1[2] c_1[3] c_1[4]

thermo_style custom step ke pe etotal press
thermo       1000

#dump	     2 all image 10000 image.*.jpg type type zoom 2.0 &
#             adiam 1.5 body type 0 0
#dump_modify  2 pad 6

run          ${steps}