Short range order and stability of a mechanically alloyed Cr25Nb75 glass determined by total scattering and first principles

Antipas, Georgios S.E.

doi:10.1590/1516-1439.323014

Cited by 5 publications

(5 citation statements)

References 14 publications

(28 reference statements)

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“…1 ) that both total and partial RDF and coordination may be calculated. All calculations of PDF, RDF and coordination were performed with the PRDF program [13] , [14] , [15] , [16] .…”

Section: Methodsmentioning

confidence: 99%

Human Cytomegalovirus variant peptides adapt by decreasing their total coordination upon binding to a T cell receptor

Antipas

Germenis

2015

Data in Brief

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The tertiary structure of the native Cytomegalovirus peptide (NLV) presented by HLA-A2 and bound to the RA14 T cell receptor was used as a reference for the calculation of atomic coordination differences of both the NLV as well as of a number of singly substituted NLV variants in the absence of TCR. Among the pMHC complexes, the native peptide was found to exhibit the highest total coordination difference in respect to the reference structure, suggesting that it experienced the widest structural adaptation upon recognition by the TCR. In addition, the peptide on the isolated NLV-MHC complex was over-coordinated as compared to the rest of the variants. Moreover, the trend was found to account for a set of measured dissociation constants and critical concentrations for target-cell lysis for all variants in complexation with RA14: functionally, all variant peptides were established to be either weak agonists or null peptides, while, at the same time, our current study established that they were also under-coordinated in respect to NLV. It could, thus, be argued that the most ‘efficient’ structural adaptation upon pMHC recognition by the TCR requires of the peptide to undergo the widest under-coordination possible. The main structural characteristic which differentiated the NLV in respect to the variants was a the presence of 16 oxygen atoms (waters) in the former׳s second coordination shell which accounted for over-coordination of roughly 100% and 30% in the O–O and C–O partials respectively. In fact, in the absence of second shell oxygens, the NLV peptide was decidedly under-coordinated in respect to all of the variants, as also suggested by the C–C partial.

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“…1 ) that both total and partial RDF and coordination may be calculated. All calculations of PDF, RDF and coordination were performed with the PRDF program [13] , [14] , [15] , [16] .…”

Section: Methodsmentioning

confidence: 99%

Human Cytomegalovirus variant peptides adapt by decreasing their total coordination upon binding to a T cell receptor

Antipas

Germenis

2015

Data in Brief

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“…So far, however, there has been little discussion about the results of the compactness of the structure of these glasses, the variation of glass transition temperature, the free volume percentage FVP, the value of the fragility index m and the other related parameters. Therefore, in the current study, the chemical bond approach has been used to explain the correlation between the above-mentioned parameters and the coordination number in the present glassy system, and the observed behavior is interpreted as an indirect evidence of the behavior of their chemical nature [19].…”

Section: Introductionmentioning

confidence: 97%

Analysis of chemical ordering and fragility for Ge–Se–In glasses

et al. 2015

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Decreasing the band gap of a material due to metal impurities has been approved through several studies, and this subject is considered as a major area of interest within the optoelectronic applications. Indium-based chalcogenides have been considered good candidates in nonlinear optics due to their ability to transmit in the infrared region. Hence, Ge 18 Se 82 has been alloyed with In. The nature of the chemical ordering of amorphous samples of Ge 18 Se 82-x In x (x = 0, 2, 4 and 6) have been systematically studied. The aim of present investigation is to understand the role of chemical composition and meancoordination number in determining their structural and physical properties. The compactness, d, of alloyed samples has been calculated from their measured densities, and values obtained have been interpreted using the topological model proposed to describe the atomic arrangements in these alloys. The variation of the glass transition temperature, T g , with the average coordination number, Z, has been investigated. The compositional dependence of the mean atomic volume, V m , has also been determined. The free volume percentage, FVP, in Ge 18 Se 82-x In x amorphous samples and their fragility indices, m, have been determined to examine the relationship with the mean-coordination number. We have also analyzed the obtained results on the basis of average single bond energy and electronegativity.

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“…On the other hand, the topological quantification of amorphous structures such as with tools ring statistics and Voronoi polyhedral analyses has been used to characterize the atomic configurations of covalent and metallic amorphous solids, respectively [1,2,[9][10][11][12][13][14][15][16][17][18][19]. These methods do not restrict the number of atoms to be considered, and are useful as regards classification of the various many-body atomic structures in certain situations.…”

Section: Introductionmentioning

confidence: 99%

Persistent homology and many-body atomic structure for medium-range order in the glass

et al. 2015

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Abstract. Characterization of medium-range order in amorphous materials and its relation to short-range order is discussed. A new topological approach is presented here to extract a hierarchical structure of amorphous materials, which is robust against small perturbations and allows us to distinguish it from periodic or random configurations. The method is called the persistence diagram (PD) and it introduces scales into manybody atomic structures in order to characterize the size and shape. We first illustrate how perfect crystalline and random structures are represented in the PDs. Then, the medium-range order in the amorphous silica is characterized by using the PD. The PD approach reduces the size of the data tremendously to much smaller geometrical summaries and has a huge potential to be applied to broader areas including complex molecular liquid, granular materials, and metallic glasses.

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Short range order and stability of a mechanically alloyed Cr25Nb75 glass determined by total scattering and first principles

Cited by 5 publications

References 14 publications

Human Cytomegalovirus variant peptides adapt by decreasing their total coordination upon binding to a T cell receptor

Human Cytomegalovirus variant peptides adapt by decreasing their total coordination upon binding to a T cell receptor

Analysis of chemical ordering and fragility for Ge–Se–In glasses

Persistent homology and many-body atomic structure for medium-range order in the glass

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