Using two "fix move" commands

Submitted by Sounik on Thu, 08/02/2018 - 00:17

Hi Liggghts Forum,

I have a compressed box of particles. The top layer of the particles needs to be moved horizontally in one direction(+y), while the bottom layer in the opposite direction(-y).

I created two groups (edge & edge1) for the particles in the top and the bottom layer respectively. My command for moving the particles are:

fix edge all move linear 0.0 0.08 0.0 units box
fix edge1 all move linear 0.0 -0.08 0.0 units box

But, the problem is only the last line of move style is working, the first line is ignored. For example, if I use "fix edge" followed by "fix edge1", only the later is considered. If the order is reversed, only "fix edge" is considered.

How can I solve the problem, where both groups edge and edge1 could be considered while using fix move.

Thanks,
Sounik

jsams | Thu, 08/02/2018 - 06:06

It looks like you have set your fix IDs to edge and edge1, respectively; however, you have the same group ID (i.e. all) for both fixes. If you want to apply a fix to the specific group of particles only, you need to change the group IDs in your fix.

I hope that works. Cheers