Insertion of particles takes too much time!

Hi all,

I am going to insert particles in a box as follows, but this take too much time ( about 10 days with 120 cores)!
I would be pleased if anyone knows why!

--------------------------------------------------------------------------my input----------------------------------------------------------------
# insert granular particles into channel

echo both

atom_style granular
atom_modify map array
communicate single vel yes

boundary f f f
newton off
units si

region reg block 0.0 7.0 0.0 0.37 0.0 0.02 units box
create_box 2 reg

neighbor 0.00072 bin
neigh_modify delay 0

variable yMp1 equal 70.e9
variable yMwall equal 200.e9
variable cRFp1p1 equal 0.01
variable cRFp1wall equal 0.01
variable cRFwallp1 equal 0.01
variable cRFwallwall equal 0.01
variable pRp1 equal 0.18
variable pRwall equal 0.37
variable cRp1p1 equal 0.6
variable cRp1wall equal 0.5
variable cRwallp1 equal 0.5
variable cRwallwall equal 0.6
variable cFp1p1 equal 0.6
variable cFp1wall equal 0.4
variable cFwallp1 equal 0.4
variable cFwallwall equal 0.8

#Material properties required for new pair styles
fix m1 all property/global youngsModulus peratomtype ${yMp1} ${yMwall}
fix m2 all property/global poissonsRatio peratomtype ${pRp1} ${pRwall}
fix m3 all property/global coefficientRollingFriction peratomtypepair 2 ${cRFp1p1} ${cRFp1wall} ${cRFwallp1} ${cRFwallwall}
fix m4 all property/global coefficientRestitution peratomtypepair 2 ${cRp1p1} ${cRp1wall} ${cRwallp1} ${cRwallwall}
fix m5 all property/global coefficientFriction peratomtypepair 2 ${cFp1p1} ${cFp1wall} ${cFwallp1} ${cFwallwall}
fix m6 all property/global characteristicVelocity scalar 2.

#pair style
pair_style gran model hertz tangential history rolling_friction cdt #Hertzian without cohesion
pair_coeff * *

#timestep, gravity
timestep 5e-8
#fix ts_check all check/timestep/gran 10000 0.1 0.1

fix gravi all gravity 9.81 vector 0.0 -1.0 0.0

#walls
fix xwalls1 all wall/gran model hertz tangential history primitive type 1 xplane 0.0
fix xwalls2 all wall/gran model hertz tangential history primitive type 1 xplane 4.5
fix ywalls1 all wall/gran model hertz tangential history primitive type 1 yplane 0.0
fix ywalls2 all wall/gran model hertz tangential history primitive type 1 yplane 0.37
fix zwalls1 all wall/gran model hertz tangential history primitive type 1 zplane 0.0
fix zwalls2 all wall/gran model hertz tangential history primitive type 1 zplane 0.02

#particle distributions
region ab block 0.0 4.5 0.02 0.03 0.0 0.02 units box
fix pts1 all particletemplate/sphere 1000001 atom_type 1 density constant 2650 radius constant 0.00036
fix pdd1 all particledistribution/discrete 1000001 1 pts1 1.0

fix ins_mesh1 all mesh/surface file mesh/face1.stl type 1
group nve_group1 region ab
fix ins1 nve_group1 insert/stream seed 1000001 distributiontemplate pdd1 nparticles 360000 &
vel constant 0.0 0.0 0.01 particlerate 70000 &
overlapcheck yes insertion_face ins_mesh1 extrude_length 0.005

#apply nve integration to all particles that are inserted as single particles
fix integr1 nve_group1 nve/sphere

#screen output
compute 1 all erotate/sphere
thermo_style custom step atoms ke c_1 vol
thermo 1000
thermo_modify lost ignore norm no
compute_modify thermo_temp dynamic yes

#insert the first particles so that dump is not empty
run 1
dump dmp all custom 100000 post/dump.liggghts_init id type type x y z ix iy iz vx vy vz fx fy fz omegax omegay omegaz radius

restart 10000000 restart1*.bin

run 100000000 upto
unfix ins1

run 110000000 upto

write_restart bed.restart
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Thanks;
Elham