Molecular simulation of the homogeneous crystal nucleation of carbon dioxide

Leyssale, J-M; Delhommelle, J; Millot, C

dc.contributor.author	Leyssale, J-M	en
dc.contributor.author	Delhommelle, J	en
dc.contributor.author	Millot, C	en
dc.date.accessioned	2014-03-01T01:22:47Z
dc.date.available	2014-03-01T01:22:47Z
dc.date.issued	2005	en
dc.identifier.issn	0021-9606	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/16652
dc.subject.classification	Physics, Atomic, Molecular & Chemical	en
dc.subject.other	Crystal nuclei	en
dc.subject.other	Homogeneous nucleation	en
dc.subject.other	Molecular simulation	en
dc.subject.other	Polymorphs	en
dc.subject.other	Chemical activation	en
dc.subject.other	Computer simulation	en
dc.subject.other	Crystallization	en
dc.subject.other	Crystals	en
dc.subject.other	Free energy	en
dc.subject.other	Molecular dynamics	en
dc.subject.other	Nucleation	en
dc.subject.other	Probability	en
dc.subject.other	Supercooling	en
dc.subject.other	Thermodynamics	en
dc.subject.other	Carbon dioxide	en
dc.title	Molecular simulation of the homogeneous crystal nucleation of carbon dioxide	en
heal.type	journalArticle	en
heal.identifier.primary	10.1063/1.1897696	en
heal.identifier.secondary	http://dx.doi.org/10.1063/1.1897696	en
heal.identifier.secondary	184518	en
heal.language	English	en
heal.publicationDate	2005	en
heal.abstract	We report on a molecular simulation study of the homogeneous nucleation of CO2 in the supercooled liquid at low pressure (P=5 MPa) and for degrees of supercooling ranging from 32% to 60%. In all cases, regardless of the degree of supercooling, the structure of the crystal nuclei is that of the Pa3 phase, the thermodynamically stable phase. For the more moderate degree of supercooling of 32%, the nucleation is an activated process and requires a method to sample states of high free energy. In this work, we apply a series of bias potentials, which promote the ordering of the centers of mass of the molecules and allow us to gradually grow crystal nuclei. The reliability of the results so obtained is assessed by studying the evolution of the nuclei in the absence of any bias potential, and by determining their probability of growth. We estimate that the size of the critical nucleus, for which the probability of growth is 0.5, is approximate to 240 molecules. Throughout the nucleation process, the crystal nuclei clearly exhibit a Pa3 structure, in apparent contradiction with Ostwald's rule of stages. The other polymorphs have a much larger free energy. This makes their formation highly unlikely and accounts for the fact that the nucleation of CO2 proceeds directly in the stable Pa3 structure. (c) 2005 American Institute of Physics.	en
heal.publisher	AMER INST PHYSICS	en
heal.journalName	Journal of Chemical Physics	en
dc.identifier.doi	10.1063/1.1897696	en
dc.identifier.isi	ISI:000229275600059	en
dc.identifier.volume	122	en
dc.identifier.issue	18	en
dc.identifier.spage	1	en
dc.identifier.epage	10	en