Accessing force due to deformation from "fix deform" command

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1

Hi all,

I am trying to access the force resulting purely from deformation applied through “fix deform” command, while integrating via NVE. Using the “fix store/force” or “fix store/state” won’t work here, since fix deform does not store any per-atom forces, unlike constraints like “fix indent” which affect forces directly. I have checked this by issuing fix store/force after “fix nve” and “fix deform”, which return the same per-atom force at a time step.

Is there another way to store these forces? I would like to eventually compute the work done by the deformation force.

Thanks in advance,

Raghavan

2

There is no per-atom force calculated or applied by fix deform. It simply
deforms the simulation box and (if requested) remaps the atoms within
the box. Maybe what you want is PV work, which could be estimated by
tracking the pressure (components) as the box deforms and the volume
changes.

Steve