particles of frozen wall are composing a group as big particle for fix srd command

I defined a group is composed of particles of frozen wall as big group in fix srd command.I used pair_style cut/lj to define interaction between them. But when i visualized dump file,i did not see interaction between particles of frozen wall and srd particles. Because i was seeing that srd particles pass through wall. I think srd paticles could not see wall particles at all.Do you have any suggestion about what kind of interaction is appropriate between srd particles and wall?

How did you define your "big" particles and their size?
For spherical particles they need to be atom_style sphere
with a per-particle radius.


I wrote a code with lammps commands ( for example, lattice custom 0.4 basis 0.0 0.0 0.0 spacing 1.0 1.0 1.0 ) to make a wall. then i used XYZ coordinates of wall’s particles that were printed in dump file as wall’s coordinates to define frozen wall and set wall’s particles as big particles in a group that i called its group-ID in fix srd command
wall was composed of spherical particles with diameter=1.0 and density=1.0

for atom_style sphere, we should define id type diameter density xyz in data file and i defined these properties in data file as written in following :
id type diameter density x y z
42 1 1 1 23.332 0.709 0
Are size of wall particles and srd particles important to define interaction between them?


i have one off-topic suggestion
(i have no clue about SRD and
don't really understand what you
are trying to do or asking about,
so i cannot help there).

would you mind to change your
e-mail configuration to send out
text mode e-mails or at least
change the font size to a more
normal pitch?

your e-mail text displays at more than
twice the size of everybody else's,
which feels like the visual equivalent
to somebody screaming into my ears
because i am hard of hearing.

i would appreciate your consideration.


The size of the "big" particles defined for SRD are certainly
important. That's how the SRD particle decides if it is
going to collide and bounce off the big particle. If the radii
are too small then your walls will have holes, and SRD particles
will move thru it.