Lines of doubly- and triply-charged emitters are present in atmospheres of hot
(A and B) stars (
K) where Stark broadening
mechanism is important. Moreover for such plasma conditions, it is the main
pressure broadening mechanism. Also, as it was shown in
Popovic &
Dimitrijevic (1996a), in stellar atmospheres there exist conditions where
Stark widths are comparable and even up to one order magnitude larger than the
corresponding thermal Doppler widths. Consequently, Stark width data for a
large number of transitions in many atomic and ionic spectra are needed for
modeling of hot stellar
plasma. Even in cooler stars, Stark broadening data for
multicharged ion species may be of interest for the modeling of
subphotospheric layers, for radiative transfer and opacity calculations, as
well as for further developement of the physics of stellar interiors
(Seaton
1987).
The increase of the number of spectral lines of astrophysical interest is additionally stimulated with the development of the space observations. Leckrone et al. (1993) investigating chemically peculiar stars with the Goddard High Resolution Spectrograph (GHRS) on the Hubble Space Telescope (HST) have found that "begining at Z=32 (germanium) and extending to heavier elements, there is a dramatic increase in the magnitude of overabundance. All species between Z=32 and Z=56 analysed are overabundant relative to the Sun".
Here we present Stark broadening parameters for three ionized elements which
lines are present in spectra of hot star atmospheres.
Manganese is overabundant in atmospheres of Hg-Mn stars
(Heacox 1979; Cowley 1980;
Smith & Dworetsky 1993 etc.), and lines of
singly and doubly charged manganese ions are observed in stellar atmospheres
(Heacox 1979; Cowley 1980;
Smith & Dworetsky 1993).
Takada-Hidai et al. (1986) have analysed Ga II and Ga III lines in high
resolved IUE spectra observed for 53 B and A stars and they have found an
overabundance of gallium in the magnetic Si and Si Cr Eu stars, in the non-
magnetic Hg-Mn stars and in the He-weak PGa stars (for gallium
overabundance analyses see also e.g.
Heacox 1979 and Smith 1995). They have
used for the spectrum synthesis models with 
- 17000 K and
, where the Stark broadening is the main pressure broadening
mechanism and where the inclusion of this mechanism is of importance
(Dimitrijevic & Artru 1986). Moreover,
Smith (1995) underlines the
importance of gallium spectral lines for the detection of stratification effects
in HgMn stars.
Spectral lines of germanium (Ge II, Ge III) are present in hot star spectra, as
e.g. in 
Ori (Selvelli et al. 1977) spectrum. They may be additionally
of interest for stellar interior physics since germanium is commonly associated
with slow-neutron capture nucleosynthesis (Leckrone et al. 1993).
In order to provide to astrophysicists the Stark broadening data needed for stellar spectra analysis and synthesis as well as for astrophysical and physical plasmas research and modelling, an effort has been made (see Dimitrijevic 1996 and references therein) to obtain the needed data within the semiclassical perturbation approach, developed by Sahal-Bréchot (1969a,b) and improved and updated several times (Sahal-Bréchot 1974; Fleurier et al. 1977; Dimitrijevic & Sahal-Bréchot 1984 1995; Dimitrijevic et al. 1991). In the case where the semiclassical perturbation approach is not applicable with an appropriate accuracy due to the lack of reliable atomic energy levels data, the simpler, modified semiempirical approach (Dimitrijevic & Konjevic 1980) has been applied.
| Transition | T (K) |  (nm) |  (nm) |  (nm) |
 | 2500 | .0246 | .0166 | .0266 |
| Mn II | 5000 | .0174 | .0117 | .0190 |
 | 10000 | .0123 | .0083 | .0144 |
| 20000 | .00870 | .00587 | .0114 |
multiplet
obtained by using different approximations
(Dimitrijevic 1982). Used
notation: 
- calculation with the modified semiempirical approach
(Dimitrijevic & Konjevic 1980), - semiempirical approach
(Griem 1968), - semiclassical theory of
Jones et al. (1971)
| Transition | T (K) | (nm) |
(nm) | WG(nm) |
 | 2500 | .00325 | .00229 | .00436 |
| Ga III | 5000 | .00230 | .00162 | .00311 |
 | 10000 | .00163 | .00114 | .00223 |
| 20000 | .00115 | .000808 | .00163 | |
| 40000 | .000814 | .000571 | .00123 |
multiplet
(Dimitrijevic & Artru 1986). 
- aproximate semiclassical
method (Griem 1974)
Here we have calculated within the semiclassical perturbation formalism (Sahal-Bréchot 1969a,b) electron-, proton-, and He III-impact line widths and shifts for 3 Ge IV lines. Moreover, Stark widths and shifts for 16 Mn II, 3 Mn III, 7 Ga III, 8 Ge III and 13 Ge IV lines for which there is not a set of reliable atomic energy level data sufficiently complete to achieve the appropriate accuracy of the semiclassical perturbation method, have been calculated within the modified semiempirical approach (Dimitrijevic & Konjevic 1980 and for ions with complex spectra see also Popovic & Dimitrijevic 1996b).