[lammps-users] modifying pair interactions using addforce

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1

Hi,

I was just wondering: while one can always write a new pair style in lammps, is it possible to include a modification of an existing pair style (like adding an extra term perhaps) by using an “addforce” command together with an appropriate “compute pair/local” and accessing nearest neighbor distances. Has anyone here tried this out? This may be a simpler option than writing C++ code !! Should there be a performance degradation once done in this way? Will this computation be automatically parallelized?

All the best
Surajit

2

Anything is possible, but I'm not clear how you
expect the fix addforce command to do anything
pairwise. It simply adds a force to each atom,
and doesn't look at pairs. You could write a new
fix that looped over atoms and their neighbors (like
a pair style does) and added a force to each pair.
It would be parallel. But that's essentially a pair
style. Also you would lose the machinery in a
pair style that does the energy and virial correctly.

Steve