02316nas a2200265   4500008004100000022001400041245008000055210006900135260000800204300001100212490000900223520150000232653001001732653000901742653002301751653002001774653002501794653001201819653002001831100001901851700002401870700002201894700003401916856010001950       2019                        eng d  a1742-546800aComparative study of a class of mean field theories of the glass transition0 aComparative study of a class of mean field theories of the glass  cAUG  a0840080 v20193 a<p>In a recently developed microscopic mean field theory, we have shown that the dynamics of a system, when described only in terms of its pair structure, can predict the correct dynamical transition temperature. Further, the theory predicted the difference in dynamics of two systems (the Lennard-Jones and the Weeks-Chandler-Andersen) despite them having quite similar structures. This is in contrast to the Schweizer-Saltzman (SS) formalism which predicted the dynamics of these two systems to be similar. The two theories although similar in spirit have certain differences. Here we present a comparative study of these two formalism to find the origin of the difference in their predictive power. We show that not only the dynamics in the potential energy surface, as described by our earlier study, but also that in the free energy surface, like in the SS theory, can predict the correct dynamical transition temperature. Even an approximate one component version of our theory, similar to the system used in the SS theory, can predict the transition temperature reasonably well. Interestingly, we show here that despite the above mentioned shortcomings the SS theory can actually predict the correct transition temperatures. Thus microscopic mean field theories of this class which express dynamics in terms of the pair structure of the liquid while being unable to predict the actual dynamics of the system are successful in predicting the correct dynamical transition temperature.</p>
10aaging10aetc)10aglasses (colloidal10aglassy dynamics10amode coupling theory10aPolymer10aslow relaxation1 aSaha, Indranil1 aNandi, Manoj, Kumar1 aDasgupta, Chandan1 aBhattacharyya, Sarika, Maitra  uhttps://library.ncl.res.in/content/comparative-study-class-mean-field-theories-glass-transition02638nas a2200229   4500008004100000022001400041245008700055210006900142260000900211300001100220490000900231520187900240653003002119653001202149653002002161653002002181653001502201100001802216700002102234700003402255856011902289       2025                        eng d  a1742-546800aStructure-dynamics correlation and its link to fragility and dynamic heterogeneity0 aStructuredynamics correlation and its link to fragility and dyna  cSEP   a0940050 v20253 a<p>
	Understanding the connection between structure, dynamics, and fragility, the rate at which the relaxation time grows with the decreasing temperature, is central to unravelling the glass transition. Fragility is often associated with dynamic heterogeneity, implying that if the structure influences the dynamics, more fragile systems should exhibit stronger structure-dynamics correlations. In this study, we test the generality of this assumption using the Lennard-Jones (LJ) and Weeks-Chandler-Andersen systems, where the fragility is tuned via the density, and a modified LJ (q, p) system, where the fragility is varied by changing the potential softness. We define a structural order parameter based on a mean-field caging potential and analyse the energy barriers at both the macroscopic and microscopic levels. While the macroscopic free energy barrier slope correlates with fragility, the microscopic free energy barrier does not show a consistent trend. Instead, it exhibits a strong correlation with a structure-dynamics correlation measure obtained from isoconfigurational ensemble simulations. Interestingly, the two systems showing the highest structure-dynamics correlation, LJ at rho = 1.1 and the (8, 5) model, are respectively the least and most fragile within their classes. These systems exhibit broad mobility distributions and large non-Gaussian parameters but low four-point susceptibilities, suggesting a decoupling between the spatial correlation length and mobility contrast. Both systems lie in the enthalpy-dominated regime and are close to the spinodal, pointing to mechanical instability as a source of heterogeneity. Our results reveal that the structure-dynamics correlation is more closely linked to the contrast in individual particle mobility than to the spatial extent of dynamic correlations that typically scale with fragility.</p>
10adynamical heterogeneities10aGlasses10aglassy dynamics10aslow relaxation10astructural1 aSharma, Mohit1 aSastry, Srikanth1 aBhattacharyya, Sarika, Maitra  uhttps://library.ncl.res.in/content/structure-dynamics-correlation-and-its-link-fragility-and-dynamic-heterogeneity