problem with "group" command and neighbors

Submitted by alejandro saez on Thu, 05/02/2019 - 00:21

Hello everyone, I tell you that I am a new user in LIGGGHTS, and I am working on a program modeling a system consisting of a belt, barriers, box and board. In the latter, the particles fall to the belt that moves at 5 m / s, where they are finally deposited in the box. However, the program does not run, because the following messages appear:

"0 atoms group group" ... .. (does the "group" command work correctly?)
"Error on proc 0: Too many neighbor bins (../neigbor.cpp:1776) .......... (What happens to the neighbors?)

Two other situations that complicate me, occurs in the global variables:
First: The coefficient of restitution does not allow entering the number zero as a value, so I used the value 0.6e-1. Why does this situation happen?
Second: In Young's module, if values of the order of 1e9 are taken, it forces me to take the condition of "hard particles". Why does this situation happen?

This is the program. Please, I need help to solve this problem and make the program run. I do not know what is happening.

Best regards to all.

# Program name: ejemplo_punto_transferencia

## Initialization of parameters

atom_style granular
atom_modify map array
hard_particles yes
boundary m m m
newton off
communicate single vel yes
units si
region reg block -0.60 0.10 -2.85 0.10 -0.20 1.40 units box
create_box 4 reg
neighbor 0.002 bin
neigh_modify delay 0
#neigh_modify delay 0 binsize 0.01
#neigh_modify every 1 check no

## Physical model

pair_style gran model hertz tangential history rolling_friction cdt
pair_coeff * *
timestep 9.37e-6
fix gravedad all gravity 9.81 vector 0.0 0.0 -1.0

## Material properties.

fix m1 all property/global youngsModulus peratomtype 250.e6 2.7e9 182.e9 100.e6
fix m2 all property/global poissonsRatio peratomtype 0.38 0.35 0.3 0.45
fix m3 all property/global coefficientRestitution peratomtypepair & 4 0.7 0.65 0.66 0.4 0.65 0.6e-1 0.6e-1 0.6e-1 0.66 0.6e-1 0.6e-1 0.6e-1 0.4 0.6e-1 0.6e-1 0.6e-1
fix m4 all property/global coefficientFriction peratomtypepair 4 & 0.3 0.32 0.27 0.7 0.32 0 0 0 0.27 0 0 0 0.7 0 0 0
fix m5 all property/global coefficientRollingFriction peratomtypepair 4 0.1 0.2 0.2 0.2 0.2 0 0 0 0.2 0 0 0 0.2 0 0 0

## CAD geometry.

fix correa all mesh/surface file meshes/correa.stl type 4 surface_vel 0 5 0
fix barreras all mesh/surface file meshes/barreras.stl type 2
fix caja all mesh/surface file meshes/caja.stl type 3
fix placa all mesh/surface file meshes/placa.stl type 2
fix sistema all wall/gran model hertz tangential history rolling_friction cdt mesh n_meshes 3 meshes correa barreras caja

## Insert particles.

group grupo region reg # (This does not recognize him does not understand the program when running)

fix pellet all particletemplate/sphere 15485863 atom_type 1 density constant 925 radius constant 0.028
fix pellets all particledistribution/discrete 32452843 1 pellet 1.0
fix insertar_particulas grupo insert/stream seed 32452867 & distributiontemplate pellets & nparticles 100000 massrate 11.39 insert_every 10000 overlapcheck &
yes all_in no vel constant 0.0 0.0 -1.0 insertion_face placa

## Calculations and output variables

fix integrar grupo nve/sphere
compute rke all erotate/sphere
thermo_style custom step atoms ke c_rke vol
thermo 1000
thermo_modify lost ignore norm no

## Run the simulation and record output information.

run 1
dump dmp all custom 1000 post/dump*.ejemplo_punto_transferencia id & type mass x y z ix iy iz vx vy vz fx fy fz omegax omegay omegaz radius
run 747065 upto

The particles fall vertically from the plate with speed -1 m / s to the belt. The belt moves at 5 m / s to transport the particles so that they are deposited in the box.

Do you need me to send you the files in STL format?

The above, does it affect if I use Ubuntu 18.04? I use it currently

alejandro saez | Thu, 05/02/2019 - 04:05

Hello everyone, can repair some things that complicated me.

However, I still get the following error message that does not allow me to run the program:

"ERROR: Could not find fix group ID"

How do I solve this problem?

Greeting to all

jvvelez | Wed, 09/25/2019 - 17:13

You defined the group before the particles have finished inserting. Ideally, you should run insertion of particles first and then define group and then run some other process you're doing