  We present in this paper electron impact broadening for six Ar XV lines using
our quantum mechanical formalism and the semiclassical perturbation one.
Additionally, our calculations of the corresponding atomic structure data
(energy levels and oscillator strengths) and collision strengths are given as
well. The lines considered here are divided into two sets: a first set of four
lines involving the ground level: 1s$^{2}2$s$^{2}$ $^{1}$S$_{0}-$1s$^{2}2$s$n$p
$^{1}$P$^{\rm o}_{1}$ where $2\leq n \leq5$ and a second set of two lines
involving excited levels: 1s$^{2}2$s2p $^{1}$P$^{\rm o}_{1}-$1s$^{2}2$s3s
$^{1}$S$_{0}$ and 1s$^{2}2$s2p $^{3}$P$^{\rm o}_{0}-$1s$^{2}2$s3s
$^{3}$S$_{1}$. An extensive comparison between the quantum and the
semiclassical results was performed in order to analyze the reason for
differences between quantum and semiclassical results up to the factor of two.
It has been shown that the difference between the two results may be due to the
evaluation of strong collision contributions by the semiclassical formalism.
Except few semiclassical results, the present results are the first to be
published. After the recent discovery of the far UV lines of Ar VII in the
spectra of very hot central stars of planetary nebulae and white dwarfs, the
present -and may be further- results can be used also for the corresponding
future spectral analysis.
