On the role of inherent structures in glass-forming materials: I. The vitrification process

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	2014-03-01T01:28:57Z
dc.date.available	2014-03-01T01:28:57Z
dc.date.issued	2008	en
dc.identifier.issn	1520-6106	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/19040
dc.subject.classification	Chemistry, Physical	en
dc.subject.other	Cooling	en
dc.subject.other	Dynamics	en
dc.subject.other	Freezing	en
dc.subject.other	Glass	en
dc.subject.other	Model structures	en
dc.subject.other	Molecular dynamics	en
dc.subject.other	Poisson distribution	en
dc.subject.other	Poisson equation	en
dc.subject.other	Potential energy	en
dc.subject.other	Quantum chemistry	en
dc.subject.other	Rate constants	en
dc.subject.other	Supercooling	en
dc.subject.other	Vitrification	en
dc.subject.other	Atomistic molecular-dynamics	en
dc.subject.other	Coarse-grained	en
dc.subject.other	Cooling processes	en
dc.subject.other	Cooling rate	en
dc.subject.other	Cooling rates	en
dc.subject.other	First-order kinetic	en
dc.subject.other	Glass transition temperature Tg	en
dc.subject.other	Glass-forming materials	en
dc.subject.other	Highly nonlinear	en
dc.subject.other	Inherent structures	en
dc.subject.other	Lennard-jones	en
dc.subject.other	Mean-square displacement	en
dc.subject.other	Poisson process approximation	en
dc.subject.other	Poisson processes	en
dc.subject.other	Potential energy landscapes	en
dc.subject.other	Simplified models	en
dc.subject.other	Super-cooled liquids	en
dc.subject.other	Time scaling	en
dc.subject.other	Two-component	en
dc.subject.other	Vitrification process	en
dc.subject.other	Glass transition	en
dc.title	On the role of inherent structures in glass-forming materials: I. The vitrification process	en
heal.type	journalArticle	en
heal.identifier.primary	10.1021/jp801296k	en
heal.identifier.secondary	http://dx.doi.org/10.1021/jp801296k	en
heal.language	English	en
heal.publicationDate	2008	en
heal.abstract	In this work, we investigate the role of inherent structures in the vitrification process of glass-forming materials by using a two-component Lennard-Jones mixture. We start with a simplified model that describes the dynamics of the atomistic system as a Poisson process consisting of a series of transitions from one potential energy minimum (inherent structure) to another, the rate of individual transitions being described by a first-order kinetic law. We investigate the validity of this model by comparing the mean square displacement resulting from atomistic molecular dynamics (MD) trajectories with the corresponding mean square displacement based on inherent structures. Furthermore, in the case of vitrification via stepwise cooling, we identify the role of the potential energy landscape in determining the properties of the resulting glass. Interestingly, the cooling rate is not sufficient to define the resulting glass in a stepwise cooling process, because the time spent by the system at different temperatures (length of the steps) has a highly nonlinear impact on the properties of the resulting glass. In contrast to previous investigations of supercooled liquids, we focus on a range of temperatures close to and below the glass transition temperature, where the use of MD is incapable of producing equilibrated samples of the metastable supercooled state. Our aim is to develop a methodology that enables mapping the dynamics under these conditions to a coarse-grained first-order kinetic model based on the Poisson process approximation. This model can be used in order to extend our dynamical sampling ability to much broader time scales and therefore allow us to create computer glasses with cooling rates closer to those used experimentally. In a continuation to this work,1 we provide the mathematical formulation for lifting the coarse-grained Poisson process model and reproducing the full dynamics of the atomistic system. © 2008 American Chemical Society.	en
heal.publisher	AMER CHEMICAL SOC	en
heal.journalName	Journal of Physical Chemistry B	en
dc.identifier.doi	10.1021/jp801296k	en
dc.identifier.isi	ISI:000258633400029	en
dc.identifier.volume	112	en
dc.identifier.issue	34	en
dc.identifier.spage	10619	en
dc.identifier.epage	10627	en