If I have 2 different chains of different chain length, but have only
FENE bonds between monomers, shouldn't there be only 1 bond types?
While creating the data file from chain.f, it creates "2 bond types"
with "2 atom types". Does it mean that 2 chains have 2 different bonds
although the bonds are all FENE?
If you set the two types of bonds to FENE and set them to have the same FENE parameters, then what would make them different? If you are concerned about the extra time required to have two different types of bonds when you only need one, that should be negligible. You might appreciate the different types when you post-process or visualize your data.