Artificial Force for Cluster Simulation

Dear All,

In order to do the MD simulation for atomic cluster with the finite number of atoms stand on the free space, we need an artificial force to keep our atoms localize in their region, so the atoms will always interact each other. We do not want to make our atoms move from the another atoms larger than “Cutoff radius” of the potential we used even for the high temperature. Is there any artificial force in Lammps that always bring my atoms back to their region if they move away larger than “cutoff radius” of the potential I used?

Thanks for your advance, I do appreciate for your answer.

Best regards,
rizal

Dear All,
In order to do the MD simulation for atomic cluster with the finite number
of atoms stand on the free space, we need an artificial force to keep our
atoms localize in their region, so the atoms will always interact each
other. We do not want to make our atoms move from the another atoms larger
than "Cutoff radius" of the potential we used even for the high temperature.
Is there any artificial force in Lammps that always bring my atoms back to
their region if they move away larger than "cutoff radius" of the potential
I used?

there are several options of "wall" potentials. those will do the trick.
i disagree about the cutoff, though. i would place a reflective well away
from the cluster and thus make sure there are no finite size effects.

axel.

Thank you Dr. Axel for your answer. I think this trick also can be applied for the surface system if we want to keep our atoms do not run away from the surface. Is it right?

rizal

2011/3/22 Axel Kohlmeyer <[email protected]>

Thank you Dr. Axel for your answer. I think this trick also can be applied
for the surface system if we want to keep our atoms do not run away from the
surface. Is it right?

yes. for example, i've been using reflecting walls on 5 sides in this
"recording" of a LAMMPS interactive MD simulation of a surface system.

http://www.youtube.com/watch?v=Og9M7xIhW00&feature=channel_video_title

cheers,
    axel.

Thanks Dr. Axel, very nice example.

rizal

2011/3/22 Axel Kohlmeyer <[email protected]>