  New experimental results supported by theoretical analyses are proposed for
aluminum silicon carbide (Al4SiC4). A state of the art implementation of the
Density Functional Theory is used to analyze the experimental crystal
structure, the Born charges, the elastic and piezoelectric properties. The Born
charge tensor is correlated to the local bonding environment for each atom. The
electronic band structure is computed including self-consistent many-body
corrections. Al4SiC4 material properties are compared to other wide band gap
W\"urtzite materials. From a comparison between an ellipsometry study of the
optical properties and theoretical results, we conclude that the Al4SiC4
material has indirect and direct band gap energies of about 2.5eV and 3.2 eV
respectively.
