I want to do compression test and plot stress-strain curve for a gold sample at 0K. I want to apply strain in finite number of steps.
All the boundaries are periodic.
Can any one suggest me how to do this in lammps.
I would start by using fix-deform - > documentation at http://lammps.sandia.gov/doc/fix_deform.html
Use a potential for Au -> Au_u3.eam from the potentials directory of LAMMPS.
thanks for the reply.
if i understand the manual correctly, fix deform is used only for dynamics.
but i am doing compression test for statics case (0K).
I think by choosing an appropriately long simulation time and choosing the value of “N (= perform box deformation every this many timesteps)” such that the atoms equilibrate - several tens of pico-secunds is my guess; you can get a stress - vs - strain curve during compression. You can use “fix NVT” to fix the temperature at desired value.
I hope this should work (except that one must make sure that the system has equilibrated in-between deformation events).
Please bear with me in case I am missing a point.
If you want to change the box during a minimization (statics) then
use fix box/relax.