Dear Lammps users,

I am working on an 3-D periodic atomistic system and want to calculate its mechanical properties. I am planning to calculate Lame Constants for my system so that I can predict various moduli, etc. In order to do so, I need to apply tensile and shear strain onto the system and see its response stresses.

I am having confusion on how to apply a shear strain. I looked at the fix_deform command but the terms (styles) xy, yz and xz were not clear enough to me. My approach is quite simple

- Start with a minimized system
- Apply tensile or shear strain (within one step, 0.1% far within elastic limits)
- Minimize the new system/Store various stress components for the minimized system. (During this minimization, I want top and bottom surfaces to be fixed).

If anyone is aware of any other approach, I would appreciate hearing about that too.

I am quite sure that fix_deform should be the way to go but I am not sure what keywords should I use. For example, “remap”. Moreover, it seems like fix_deform does not work with minimization algorithm.

I will highly appreciate if someone who has done such calculations could guide me here.

Thanks in advance.