LIGGGHTS® - User Forum

hi every one

i have a clarification in walls
how to assign wall property like density,friction etc....
some detail about fix wall/gran command

with regards
dinesh kumar

hello everyone
I met a problem when trying to add package molecule, a similar thread was post last year but with no answers, as below:

i am very new to this software and also very new in the field of particle simulation. I am planing to do the Nanoindentation simulation through LIGGGHTS. Therefore i need to create a bond model, which is only possible through the MOLECULE package.

I have tried to install this package but it is showing some error. I have tried to do it in two steps, as mentioned in LIGGGHTS online document.

I noticed that atom_style bond/gran cant be recognized. The online documentation says "Note that bond/gran is an experimental code which is may not be available in your release of LIGGGHTS. An example for the sytnax is given below". I am wondering when it will be available to the public version user. Is this new atom_style for membrane boundary?

Hi every one

I have small clarification in liggghts compute command
why it is used?
what are the outcome of using this command?
where are the results?

please explain me about this command in briefly

with regards
Dinesh Kumar

I am quite confused why I cannot put in pxx pyy pzz etc. as the keywords to obtain the internal stress state of the periodic cell? I tried other keywords and finally find the the pxx pyy pzz are not included in the source code (am I right?). I am wondering why it is not included in the source code as it is basic and important key values.

LAMMPS are for particle size in atomic range (angstrom). What is the minimum size of particle that can be inserted in LIGGGHTS? Most of the tutorials takes millimetre sized particles. Can we take nano to sub micron size of particles in LIGGGHTS?

ERROR: Unknown command: info system (../input.cpp:258)
I am wondering whether it is a command for premium version.

Is there no way to delete regions? The documentation says that I should be able to delete a region with "region region_name delete" but when I use such a command I get an error saying I used an illegal region command.

I also am aware the documentation says deleting a region is not usually necessary, but in my case I need to delete a region and create a new one by the same name within a loop.

I'm trying to calculate the minimum height amongst different regions in my simulation. For each region, I use "compute region_height all reduce/region region_name max z" to calculate the highest particle. Now I'm trying to find the minimum of height 1, height 2, height 3, and so on. There doesn't seem to be a way I can simply call minimum(height1,height2,height3). Is there any built-in function or work-around that will allow me to find the minimum amongst different global scalars?

Is there anyone using membrane boundary in liggghts? Just like this youtube video https://www.youtube.com/watch?v=mltNl2AphNk.
Which command should I use to bond these particles as a membrane?