Dear all,

I am simulating a cylindrical confined system using fix_ wall/region command. I am getting error like"ERROR on proc 0: Particle on or inside surface of region used in fix wall/region (fix_wall_region.cpp:235)application called MPI_Abort(MPI_COMM_WORLD, 1) - process 0

"

My input script is

# LATTICE

dimension 3

units lj

atom_style atomic

boundary f f p

lattice fcc 0.893151 origin 0.0 0.0 0.0

region 2 cylinder z 0 0 3.74 -5 5 side in

region 3 cylinder z 0 0 4.24224403 -5 5

create_box 2 2

create_atoms 2 region 2 basis 1 2 basis 2 2

mass * 1.0

label chandan

variable a loop 1

variable v equal 11+$a

log log.$v

variable t equal 1.20

group d type 2

velocity all create $t 376678 dist gaussian

pair_style lj/cut 4.3811

pair_coeff * * 1.0 1.0 3.0

pair_modify shift yes

neigh_modify delay 3 every 1 check yes

fix 1 all npt temp $t $t 0.5 z 1.0 1.0 100.0 drag 0.2

fix 2 all wall/region 3 lj93 4.86386 0.9462 2.5

compute 1 all msd

variable y equal atoms/vol

variable z equal sqrt(c_1[4])/(((4/v_y)^(1/3))/sqrt(2))

fix_modify 2 energy yes

thermo_style custom temp pe vol enthalpy v_y pxx pyy pzz press lx ly lz# f_2 pe ke etotal temp pe vol enthalpy v_den f_2 pxx pyy pzz press lx ly

dump 1 all custom 2000 log.dump$v id type x y z

timestep 0.004

restart 200000 restart.o$v

thermo 400

run 200000

uncompute 1

undump 1

next a

jump liq-sol.in chandan

Can any sorted out where the error???

Thanking

Dear all,

I am simulating a cylindrical confined system using fix_ wall/region

command. I am getting error like"ERROR on proc 0: Particle on or inside

surface of region used in fix wall/region

(fix_wall_region.cpp:235)application called MPI_Abort(MPI_COMM_WORLD, 1) -

process 0

"

My input script is

[...]

Can any sorted out where the error???

what are you going to offer as a bounty?

you have a meaningful error message. isn't that enough of a hint?

it is probably best to visualize your system to find out where things

are going wrong.

axel.

The doc page for fix wall/region has this note:

IMPORTANT NOTE: For all of the styles, you must insure that r is

always > 0 for all particles in the group, or LAMMPS will generate an

error. This means you cannot start your simulation with particles on

the region surface (r = 0) or with particles on the wrong side of the

region surface (r < 0). For the {wall/lj93} and {wall/lj126} styles,

the energy of the wall/particle interaction (and hence the force on

the particle) blows up as r -> 0. The {wall/colloid} style is even

more restrictive, since the energy blows up as D = r-R -> 0. This

means the finite-size particles of radius R must be a distance larger

than R from the region surface. The {harmonic} style is a softer

potential and does not blow up as r -> 0, but you must use a large

enough {epsilon} that particles always reamin on the correct side of

the region surface (r > 0).

Steve

Thank you sir for your precious time.