Constrained simulations to count the glasses that a fluid samples

The glass transition is usually regarded as a kinetic phenomenon. This work shows that it can be treated in a purely thermodynamic way when constraints, rather than lack of time, prevent a liquid from sampling its many glasses. Molecular dynamics simulations of a hard disc mixture show that it can be made glassy, at any density, and that the glass transition is accompanied by a change in compressibility and heat capacity as at the kinetic glass transition. The constraints provide a direct method of counting the number of glasses that a fluid samples. (C) 1999 Elsevier Science B.V. All rights reserved.