[lammps-users] granular simulation

Hi dear all,

I’m having difficulties with specifying each granular particle dimensions, (diameter). When i run the dump file with VMD
i see the particle #3 colored green (while the other two are white), and it is a bit larger then the others (which are identical in size).
something probably went wrong, since I’ve specified each particle a different diameter.

another question:
now suppose the diameter issue is solved, I would like all 3 particles to shrink (starting from the inital diameter) with a different given rate (let’s say some general function, so the rate is generally can vary) as they fall.
what would be the most efficient way to code that ?

Can anybody help me out ?

Thanks in advance,
Chemistry Grad student

i have written the next code:

#data file
3 atoms
3 atom types
-25 25 xlo xhi
-70 70 ylo yhi
-25 25 zlo zhi

1 1 20.0 1.0 0 66 0
2 2 5.0 1.0 1.0 66 0
3 3 1.0 1.0 2.0 66 0

Your first Q is a VMD or viz question. A VMD person will
have to answer.

If you want to change the diam of a particle(s) during a LAMMPS
run, you could use the set command, in a loop, doing set, run, set, run,

If you want it to change continuously (every timestep), you'll need
to write a fix to do that.