Hi,
I want to build particles of complex shapes through using the multisphere approach with LIGGGHTS. I use:
atom_style hybrid granular molecular
(...)
neigh_modify delay 0 exclude molecule all
(...)
fix freezing all rigid molecule.
So far I did simulations where the beads composing a particle of complex shape have the same size. Everything works nice! Now the beads composing the complex particle can have different sizes and here I face a problem.
The problem is that setting the mass of each particle explicitly in the input file in this case can get so complicated and user-unfriendly! Indeed, in the data file each bead of different radius must be associated with a different particle type. And then consider that one particle of complex shape is built from ~ 15 beads, each of different size! Imagine then explicitly setting the mass of each bead in the input command file and then specifying all peratomtypepair quantities in the property/global entries: 1-2, 1-3, 1-4, ... 1-5, 2-1, 2-2, 2-3, 2-15, ... 15-14 (!!!).
I wonder if there isn't another way to tell LIGGGHTS that all beads building the complex particles in my datafile are of the SAME material (= all beads of same atom_type, same kn, kt..) and so the mass of each bead composing a complex particle should be automatically calculated from the parameters: radius of a bead and density (which is the same for all beads). Maybe one could simply allow the hybrid molecular granular style to read the Masses entries from the data_file (this would be a huge simplification) or let the masses be calculated from the density and radius for the hybrid molecular granular style? Wouldn't such a simplification be of general interest for LIGGGHTS granular users?
Please just tell me if there is another simpler alternative I am not aware of and thanks so much in advance for the help!
Eric