crystal was reported earlier [@Carruzzo02].

Molecular Dynamics Simulation
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We have performed a molecular dynamics simulation on a glass forming liquid [@Weber85; @Kob94] consisting of a 50:50 binary mixture of soft spheres in three dimensions. The two types of spheres, labelled A and B, differ only in their sizes. The interaction between two particles a distance $r$ apart is given by $V_{\alpha\beta}(r)
=\epsilon[(\sigma_{\alpha\beta }/r)^{12}+X_{\alpha\beta}(r)]$ where the interaction length $\sigma_{\alpha\beta }=(\sigma_{\alpha}+\sigma_{\beta})/2$ with $\sigma_B/\sigma_A=1.4$ ($\alpha$, $\beta =$ A, B). For numerical efficiency, we set the cutoff function $X_{\alpha\beta}(r)=r/\sigma_{\alpha\beta}-\lambda$ with $\lambda =13/12^{12/13}$. The interaction is cutoff at the minimum of the potential $V_{\alpha\beta}(r)$. Energy and length are measured in units of $\epsilon$ and $\sigma_A$, respectively. Temperature is given in units of $\epsilon /k_B$ where $k_B$ is Boltzmann’s constant, and time is in units of $\sigma_A\sqrt{m/\epsilon}$ where $m$, the mass of the particles, is set to unity. The equations of motion were integrated using the leapfrog method [@Rapaport95] with a time step of 0.005. During each run the average density $\rho_o=N/L^3$ was fixed, and the temperature was kept constant using a constraint algorithm [@Rapaport95]. The volume $V=L^3$. $N=N_A+N_B$ is the total number of particles. The system occupies a cube with dimensions ($\pm$ L/2, $\pm$ 