dense wall

I made a wall with diamond lattice style. I think that wall was dense enough but still SRD paticles passed it. I think this problem is due to the type of interaction between srd particles and wall particles ;and not due to the type of arrangement of particles in the wall.Because i made a wall not dense enough in the middle of a box that was filled with LJ particles as a LJ liquid and i uesd commands:
pair_style lj/cut 2.5
pair_coeff 1 1 1.0 1.0
pair_coeff 1 2 1.0 1.0 1.12
pair_coeff 2 2 1.0 1.0 1.12 ( type 1= wall group,type 2= liquid group)
for interaction between liquid particles and wall particles and LJ liquid particles could do interact with wall paticles. they did not enter to wall.
But when i use fix srd command to make polymeric liquid for my project. Unfortunately SRD particles entered to wall that i set in the middle of simulation box.I used the commands as mentioned above to set interactions. Perhaps i did not select correct interaction between srd particles and wall particles.
Do you know what interactions there are between srd particles and srd wall in fix wall/srd command?or what pair_style command i can use to set repulsive interaction between srd and typical wall particles?

The fix wall/srd command is for an idealized wall, not
a wall made of particles. Like all the fix wall commands.

SRD particles bounce off solute partilces, as set
by the fix srd command. If you made a frozen wall
of solute particles, and SRD particles passed thru
it, then there must be gaps.