Making MILES better for stellar population modelling
  In order to build more realistic single stellar population (SSP) models with
variable alpha-enhancement, we have recently determined [Mg/Fe] in a uniform
scale with a precision of about 0.1 dex for 752 stars in the MILES empirical
library. The [alpha/Fe] abundance ratio is commonly used as a good temporal
scale indicator of star formation, taking Mg as a template for alpha elements.
Calcium is another element whose abundance is currently being investigated for
the MILES stars. The MILES library is also being expanded by around 20% by
including stars with known Teff, log g, [Fe/H] and [Mg/Fe]. The transformation
of their photospheric parameters to the MILES system has been carried out, but
the calibration of their [Mg/Fe] is still in progress. In parallel, C, N and O
abundances are also being compiled from literature for the library stars
because they play an important role in the photospheric opacity, particularly
influencing the blue spectral region. The Galactic kinematic classification of
MILES stars with compiled [Mg/Fe] has been just computed such that this
information can be considered in the SSP modeling. Comparisons of theoretical
stellar predictions of the Lick line-strength indices against the MILES data
have revealed the good behaviour of Fe-sensitive indices predictions, while
highlighting areas for improvement in some models for the higher order H-Balmer
features.
