Ageing and crystallization in a lattice glass model

We have studied a the 3-$d$ lattice glass of Pica Ciamarra, Tarzia, de Candia and Coniglio [Phys.\ Rev.\ E. 67, 057105 (2013)], which has been shown to reproduce several features of the structural glass phenomenology, such as the cage effect, exponential increase of relaxation times and ageing. We show, using short-time dynamics, that the metastability limit is above the estimated Kauzmann temperature. We also find that in the region where the metastable liquid exists the aging exponent is lower that 0.5, indicating that equilibrium is reached relatively quickly. We conclude that the usefulness of this model to study the deeply supercooled regime is rather limited.