Adding monomers from a Data file to a spherical region and creating bonds to form a polymer gel

Dear all users,

I am completely new to LAMMPS . I have been trying to create a polymer gel in a spherical region, for this my data file works fine with some of the other simple codes but for this particular work i want to read the data file and add the monomers to the specified spherical region and then start creating the bonds.
I am facing the following problems:
I tried setting the dimensions but nothing seems to work

Whenever i try to create bonds using create_bonds or fix create_bonds the monomers seem to aggregate at the center, the similar thing happened when i tried making bonds in a system of random atoms . They do form bonds but for some reason they aggregate at the center.
I have attached my input script and data files for reference

I think i might have made some mistake in giving the potential coefficients.
Please tell me where I am wrong??

Thanks in advance

sphere.in (2.06 KB)

melt.in (1.34 KB)