01546nas a2200181 4500008004100000022001400041245012900055210006900184260007900253300001100332490000800343520078600351100002201137700002501159700002101184700003401205856012501239 2014 eng d a0031-900700aRole of structure and entropy in determining differences in dynamics for glass formers with different interaction potentials0 aRole of structure and entropy in determining differences in dyna aONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USAbAMER PHYSICAL SOCcNOV a2257010 v1133 a

We present a study of two model liquids with different interaction potentials, exhibiting similar structure but significantly different dynamics at low temperatures. By evaluating the configurational entropy, we show that the differences in the dynamics of these systems can be understood in terms of their thermodynamic differences. Analyzing their structure, we demonstrate that differences in pair correlation functions between the two systems, through their contribution to the entropy, dominate the differences in their dynamics, and indeed overestimate the differences. Including the contribution of higher order structural correlations to the entropy leads to smaller estimates for the relaxation times, as well as smaller differences between the two studied systems.

1 aBanerjee, Atreyee1 aSengupta, Shiladitya1 aSastry, Srikanth1 aBhattacharyya, Sarika, Maitra uhttps://library.ncl.res.in/content/role-structure-and-entropy-determining-differences-dynamics-glass-formers-different-001826nas a2200193 4500008004100000022001400041245009300055210006900148260008700217300001100304490000800315520106800323100002401391700002201415700002501437700002101462700003401483856011501517 2015 eng d a0021-960600aUnraveling the success and failure of mode coupling theory from consideration of entropy0 aUnraveling the success and failure of mode coupling theory from  a1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScNOV a1745040 v1433 a

We analyze the dynamics of model supercooled liquids in a temperature regime where predictions of mode coupling theory (MCT) are known to be valid qualitatively. In this regime, the Adam-Gibbs (AG) relation, based on an activation picture of dynamics, also describes the dynamics satisfactorily, and we explore the mutual consistency and interrelation of these descriptions. Although entropy and dynamics are related via phenomenological theories, the connection between MCT and entropy has not been argued for. In this work, we explore this connection and provide a microscopic derivation of the phenomenological Rosenfeld theory. At low temperatures, the overlap between the MCT power law regime and AG relation implies that the AG relation predicts an avoided divergence at T-c, the origin of which can be related to the vanishing of pair configurational entropy, which we find occurring at the same temperature. We also show that the residual multiparticle entropy plays an important role in describing the relaxation time. (C) 2015 AIP Publishing LLC.

1 aNandi, Manoj, Kumar1 aBanerjee, Atreyee1 aSengupta, Shiladitya1 aSastry, Srikanth1 aBhattacharyya, Sarika, Maitra uhttps://library.ncl.res.in/content/unraveling-success-and-failure-mode-coupling-theory-consideration-entropy-102079nas a2200181 4500008004100000022001400041245012600055210006900181260008700250300002700337490000800364520129300372100002201665700002401687700002101711700003401732856013101766 2016 eng d a0021-960600aEffect of total and pair configurational entropy in determining dynamics of supercooled liquids over a range of densities0 aEffect of total and pair configurational entropy in determining  a1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScJUL aArticle Number: 0345020 v1453 a

In this paper, we present a study of supercooled liquids interacting with the Lennard Jones potential and the corresponding purely repulsive (Weeks-Chandler-Andersen) potential, over a range of densities and temperatures, in order to understand the origin of their different dynamics in spite of their structures being similar. Using the configurational entropy as the thermodynamic marker via the Adam Gibbs relation, we show that the difference in the dynamics of these two systems at low temperatures can be explained from thermodynamics. At higher densities both the thermodynamical and dynamical difference between these model systems decrease, which is quantitatively demonstrated in this paper by calculating different parameters. The study also reveals the origin of the difference in pair entropy despite the similarity in the structure. Although the maximum difference in structure is obtained in the partial radial distribution function of the B type of particles, the rdf of AA pairs and AB pairs gives rise to the differences in the entropy and dynamics. This work supports the observation made in an earlier study [A. Banerjee et al., Phys. Rev. Lett. 113, 225701 (2014)] and shows that they are generic in nature, independent of density. Published by AIP Publishing.

1 aBanerjee, Atreyee1 aNandi, Manoj, Kumar1 aSastry, Srikanth1 aBhattacharyya, Sarika, Maitra uhttps://library.ncl.res.in/content/effect-total-and-pair-configurational-entropy-determining-dynamics-supercooled-liquids-over01288nas a2200169 4500008004100000245008600041210006900127260000800196300002700204490000800231520067600239100002200915700002400937700002100961700003400982856010201016 2017 eng d00aDetermination of onset temperature from the entropy for fragile to strong liquids0 aDetermination of onset temperature from the entropy for fragile  cJUL aArticle Number: 0245040 v1473 a

In this paper, we establish a connection between the onset temperature of glassy dynamics with the change in the entropy for a wide range of model systems. We identify the crossing temperature of pair and excess entropies as the onset temperature. Below the onset temperature, the residual multiparticle entropy, the difference between excess and pair entropies, becomes positive. The positive entropy can be viewed as equivalent to the larger phase space exploration of the system. The new method of onset temperature prediction from entropy is less ambiguous, as it does not depend on any fitting parameter like the existing methods. Published by AIP Publishing.

1 aBanerjee, Atreyee1 aNandi, Manoj, Kumar1 aSastry, Srikanth1 aBhattacharyya, Sarika, Maitra uhttps://library.ncl.res.in/content/determination-onset-temperature-entropy-fragile-strong-liquids02638nas 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

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.

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