How does fluka handle when the neutron energy below 4eV?

when the neutron energy below 4eV (or 5eV) , the fact that the nuclei are in atoms which form part of a certain molecule inside a material plays an important role,
maybe the thermal neutron data libraries ar needed, especially for low A(mass number), like hydrogen in water, heavy water, polyethylene and so on.
so, How does fluka handle when the neutron energy below 4eV?

Dedicated cross section sets are indeed available for hydrogen and carbon as listed in the manual (search for bound).

@ Francesco Cerutticeruttif,thanks!