Impressing an individual additional force to each atom

Claudio Wolfer's picture
Submitted by Claudio Wolfer on Tue, 01/17/2012 - 10:28

Hi

I would like to impress a force on each atom depending on his mass, velocity an position. While searching through the manual i have found the fix command addforce. I have read "the vector is the total force on the group of atoms". So thats not what I need. But I couldn't find any other fix command that would enable my additional force. In the forum I've read that in a coming version of liggghts variables could be used in fix addforce. Is this in the newest version 1.5 possible? Would that help?
How would you impress an additional force to each atom?

Thanks for any help.
Claudio

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ckloss's picture

ckloss | Wed, 01/18/2012 - 17:17

you could try to use fix addforce from a recent LAMMPS version (there the variable style is already implemented) or hard-code your own version in a new fix addforce/claudio (copy and modify fix_addforce.h/cpp) which is more efficient

Cheers, Christoph

Claudio Wolfer's picture

Claudio Wolfer | Thu, 01/19/2012 - 15:03

Hi Christoph

I decided to change the code from fix viscous because there is the velocity dependence already integrated.

Hopefully it works.
Claudio