  We will analyze the importance of varying the diffuse gas radial distribution
on the resulting expected cosmic rays spectrum. We use the recent HI density
data published by Nakanishi et al. (2004), and include them in the cosmic rays
propagation code GALPROP (Strong & Moskalenko 1998). We will obtain those
models that reproduce the characteristics shown by the cosmic rays data, and we
will then extract information about the Galaxy structure.
