  We study temperature and density sensitivities of ratios of Si XI soft X-ray
emission lines, in the wavelength range of 43--54\AA . The typical temperature
of the formation of the analyzed lines is around 1.6~MK, which makes this
analysis complementary to the analysis of He-like triplets being sensitive to
hotter plasma. We present theoretical calculations and compare them with ratios
obtained from high-resolution X-ray spectra of five solar-like stars: Procyon,
$\alpha$ Cen A$&$B, $\epsilon$ Eri, and Capella. We find that our results are
in good agreement with results obtained by other authors through different
diagnostics, namely the analysis of density- and temperature-sensitive He-like
triplet lines. We further estimate the coronal pressure and filling factors
from Si~XI lines in this study.
