  Understanding glasses and the glass transition requires comprehending the
nature of the crossover from the ergodic (or equilibrium) regime, in which the
stationary properties of the system have no history dependence, to the
mysterious glass transition region, where the measured properties are
non-stationary and depend on the protocol of preparation. In this work we use
non-equilibrium molecular dynamics simulations to test the main features of the
crossover predicted by the \emph{molecular} version of the recently-developed
multicomponent non-equilibrium self-consistent generalized Langevin equation
(NE-SCGLE) theory. According to this theory, the glass transition involves the
abrupt passage from the ordinary pattern of full equilibration to the aging
scenario characteristic of glass-forming liquids. The same theory explains that
this abrupt transition will always be observed as a blurred crossover by the
unavoidable finiteness of the time window of any experimental observation. We
find that within their finite waiting-time window, the simulations confirm the
general trends predicted by the theory.
