  The chemi-ionization (CI) processes in atom-Rydberg-atom collisions are
investigated in this contribution. The rate coefficients for CI processes in
$\textrm{Li}^{*}(n) + \textrm{Na}$, $\textrm{Li}^{*}(n) + \textrm{Li}$,
$\textrm{Na}^{*}(n) + \textrm{Na}$ and $\textrm{H}^{*}(n)+\textrm{Li}$
collisions are calculated for wide region of temperatures $T \le 4000$ K and
the principal quantum numbers $4 \le n\le 25$. These processes are
investigated, with a particular accent on the possibility of involving alkali
metals as the factors which may influence optical properties and modeling of
weakly ionized layers of different stellar atmospheres. The obtained rate
coefficients are applied to models of the Io atmosphere. Moreover, we present
here further development of investigation of CI processes for other possible
applications in spectroscopy such as in low temperature laboratory plasma
created in gas discharges, for example in microwave-induced discharges at
atmospheric pressure, where such plasma conditions may be favorable.
