  The ability of some liquids to vitrify during supercooling is usually seen as
a consequence of the rates of crystal nucleation (and/or crystal growth)
becoming small- thus a matter of kinetics. However there is evidence, dating
back to the empirics of coal briquetting for maximum trucking efficiency, that
ellipsoids pack efficiently when disordered. Noting that key studies of
non-spherical object packing have never been followed from hard ellipsoids or
spherocylinders (diatomics excepted) into the world of molecules with
attractive forces, we have made a molecular dynamics MD study of crystal
melting and glass formation on the Gay- Berne (G-B) model of ellipsoidal
objects across the aspect ratio range of the hard ellipsoid studies. Here we
report that, in the aspect ratio range of maximum ellipsoid packing efficiency,
various G-B crystalline states, that cannot be obtained directly from the
liquid, disorder spontaneously near 0 K and transform to liquids without any
detectable enthalpy of fusion. Without claiming to have proved the existence of
single component examples, we use the present observations, together with our
knowledge of non-ideal mixing effects, to discuss the probable existence of
"ideal glassformers" - single or multicomponent liquids that vitrify before
ever becoming metastable with respect to crystals. The existence of
crystal-free routes to the glassy state removes any precrystalline fluctuation
perspective from the "glass problem". Unexpectedly we find that liquids with
aspect ratios in the "crystallophobic" range also behave in an unusual
(non-hysteritic) way during temperature cycling through the glass transition.
We link this to the highly volume fraction-sensitive ("fragile") behavior
observed in recent hard dumbbell studies at similar length/diameter ratios.
