Five discs in a box

Molecular dynamics studies of five hard discs in a square box with hard walls show states that are analogues of the fluid, crystal and glass phases of a much larger system. The behaviour of the model is described in terms of the configurational landscape, which has one crystalline and four amorphous inherent structures. A metastable supercooled fluid is stabilised when the discs are constrained to the amorphous basins. When the discs become trapped in a single basin the system is a glass. The statistical entropy decreases by k ln(4) at the glass transition and tends to that of the crystal at the same temperature and pressure, as absolute zero is approached.