  He-accreting white dwarfs with sub-Chandrasekhar mass are revisited. The
impact of the use of an extended reaction network on the predicted energy
production and characteristics of the detonating layers is studied. It is shown
that the considered scenario can be the site of an $\alpha$p-process combined
with a p-process and with a variant of the rp-process we refer to as the
pn-process. We define the conditions under which the derived distribution of
the abundances of the p-nuclides in the ejecta, including the puzzling light Mo
and Ru isotopes, mimics the solar-system one.
