[lammps-users] (no subject)

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1

Dear Lammps users,
I am sort of novice with this program.
My simple aim is to simulate one atom's movement.
I set velocity and initial coordinates but when in dump file all coordinates are constant at any step. I can't see my mistake.
Thank you for your attention.
Here is the text:
units lj
atom_style dipole
dimension 3
lattice fcc 1
region box block -100 100 -100 100 -100 100
create_box 1 box
create_atoms 1 single 1 1 5
mass 1 1.0
shape 1 1 1 1
dipole 1 0.75
pair_style dipole/cut 2.5
pair_coeff * * 1.0 1.0

neighbor 0.3 bin
neigh_modify delay 0

set group all x 1 y 1 z 1 dipole/random 98934
velocity all set 23 13 14
timestep 0.05

dump 1 all custom 10 dump.n x y z vx vy vz
run 100

2

Your simulation should have thrown up a warning, because you don’t have anything that integrates the equation of motion, hence the constant position.

Look at the LAMMPS manual to see your choices for the integrators.

–AEI

3

yes - use fix nve

And read the warnings - they are almost always important.

Steve