  The aim of this work is to draw attention to the processes of radiative
charge exchange in non-symmetric ion-atom collisions as a factor of influence
on the opacity of stellar atmospheres in VUV region. For that purpose
calculations of the spectral absorption coefficients for several ion-atom
systems, namely: He + H$^{+}$ and H + X$^{+}$, where X = Na and Li have been
performed. On chosen examples it has been established that the examined
processes generate rather wide molecular absorption bands in the VUV region,
which should be taken into account for the interpretation of data obtained from
laboratory measurements or astrophysical observations. In this paper the
potential significance is discussed of the considered radiative processes for
DB white dwarfs and solar atmospheres, as well as for the atmospheres of the
so-called lithium stars.
