Temperature Accelerated Dynamics in Glass-Forming Materials

Tsalikis, DG; Lempesis, N; Boulougouris, GC; Theodorou, DN

dc.contributor.author	Tsalikis, DG	en
dc.contributor.author	Lempesis, N	en
dc.contributor.author	Boulougouris, GC	en
dc.contributor.author	Theodorou, DN	en
dc.date.accessioned	2014-03-01T01:34:44Z
dc.date.available	2014-03-01T01:34:44Z
dc.date.issued	2010	en
dc.identifier.issn	1520-6106	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/20822
dc.subject.classification	Chemistry, Physical	en
dc.subject.other	Characteristic distance	en
dc.subject.other	Classical molecular dynamics	en
dc.subject.other	Computational costs	en
dc.subject.other	Configurational spaces	en
dc.subject.other	Euclidean	en
dc.subject.other	Exhaustive search	en
dc.subject.other	Glass forming materials	en
dc.subject.other	Glass transition temperature	en
dc.subject.other	Inherent structures	en
dc.subject.other	Lennard-Jones potential	en
dc.subject.other	Local minimums	en
dc.subject.other	Molecular simulations	en
dc.subject.other	Novel methods	en
dc.subject.other	Optimal sampling	en
dc.subject.other	Orders of magnitude	en
dc.subject.other	Plot analysis	en
dc.subject.other	Potential energy landscapes	en
dc.subject.other	Random energy models	en
dc.subject.other	Self-similar	en
dc.subject.other	Spherical atoms	en
dc.subject.other	Temperature accelerated dynamics	en
dc.subject.other	Time evolutions	en
dc.subject.other	Time-scales	en
dc.subject.other	Algorithms	en
dc.subject.other	Fractal dimension	en
dc.subject.other	Glass	en
dc.subject.other	Molecular dynamics	en
dc.subject.other	Potential energy	en
dc.subject.other	Potential energy surfaces	en
dc.subject.other	Rate constants	en
dc.subject.other	Glass transition	en
dc.title	Temperature Accelerated Dynamics in Glass-Forming Materials	en
heal.type	journalArticle	en
heal.identifier.primary	10.1021/jp908975d	en
heal.identifier.secondary	http://dx.doi.org/10.1021/jp908975d	en
heal.language	English	en
heal.publicationDate	2010	en
heal.abstract	In this work we propose a methodology for improving dynamical sampling in molecular simulations via temperature acceleration. The proposed approach combines the novel methods of Voter for temperature-accelerated dynamics with the multiple histogram reweighting method of Ferrenberg and Swendsen, its dynamical extension by Nieto-Draghi et al., and with hazard plot analysis, allowing optimal sampling with small computational cost over time scales inaccessible to classical molecular dynamics simulations by utilizing the ""inherent structure"" idea. The time evolution of the system is viewed as a succession of transitions between ""basins"" in its potential energy landscape, each basin containing a local minimum of the energy (inherent structure). Applying the proposed algorithm to a glass-forming material consisting of a mixture of spherical atoms interacting via Lennard-Jones potentials, we show that it is possible to perform an exhaustive search and evaluate rate constants for basin-to-basin transitions that cover several orders of magnitude on the time scale, far beyond the abilities of any competitive dynamical study, revealing an extreme ruggedness of the potential energy landscape in the vicinity of the glass transition temperature. By analyzing the network of inherent structures, we find that there are characteristic distances and rate constants related to the dynamical entrapment of the system in a neighborhood of basins (a metabasin), whereas evidence to support a random energy model is provided. The multidimensional configurational space displays a self-similar character depicted by a fractal dimension around 2.7 (±0.5) for the set of sampled inherent structures. Only transitions with small Euclidean measure can be considered as localized. © 2010 American Chemical Society.	en
heal.publisher	AMER CHEMICAL SOC	en
heal.journalName	Journal of Physical Chemistry B	en
dc.identifier.doi	10.1021/jp908975d	en
dc.identifier.isi	ISI:000278479900017	en
dc.identifier.volume	114	en
dc.identifier.issue	23	en
dc.identifier.spage	7844	en
dc.identifier.epage	7853	en