Non-LTE abundances of zinc in different spectral type stars and the
  Galactic [Zn/Fe] trend based on quantum data on inelastic processes in
  zinc-hydrogen collisions
  We present a new model atom of Zn I-II based on the most up-to-date
photoionisation cross-sections, electron-impact excitation rates, and rate
coefficients for the Zn I + H I collisions. The latter were calculated using
the multi-channel quantum asymptotic treatment based on the Born-Oppenheimer
approach. Non-LTE analysis was performed for the first time for lines of Zn I
and Zn II in the ultraviolet (UV) spectra of two very metal-poor reference
stars, HD 84937 and HD 140283. We found consistent non-LTE abundance from the
resonance Zn I 2138 A line, the subordinate lines, and the lines of Zn II. In
both stars, non-LTE leads to 0.17 dex higher average abundance from Zn I,
while, for Zn II lines, non-LTE corrections are minor and do not exceed 0.06
dex. Using lines of Zn I in the high-resolution spectra, we determined the
non-LTE abundances for a sample of 80 stars in the -2.5 < [Fe/H] < 0.2
metallicity range. The [Zn/Fe] versus [Fe/H] diagram reveals a dip, with
[Zn/Fe] = 0.3 in the most metal-poor stars, a close-to-solar value for [Fe/H] =
-1.2, and increasing [Zn/Fe] up to 0.3 in the thick disk stars. The
close-to-solar metallicity stars have subsolar [Zn/H] = -0.1, on average.
Non-LTE abundances of zinc were derived for the first time for seven reference
F to B-type stars. We provide a grid of the non-LTE abundance corrections.
