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15 pages, 1736 KB

Open AccessArticle

Static Local Lattice Distortion in BCC Refractory High-Entropy Alloys: A DFT Study of NbTaTiV, TiZrNbMo, and HfZrNbMo

by Tijana Đorđević, Ana Kalinić and Dejan Pjević

Metals 2026, 16(4), 412; https://doi.org/10.3390/met16040412 - 9 Apr 2026

Cited by 1 | Viewed by 1165

Local lattice distortion (LLD) arising from atomic size mismatch is an important structural feature of body-centered cubic (BCC) refractory high-entropy alloys (RHEAs). Reported LLDs are often difficult to compare across alloys because studies use different definitions and reference lattices. In this paper, we computed a consistent static DFT baseline for width-based LLD descriptors for three equimolar quaternary BCC RHEAs: NbTaTiV, TiZrNbMo, and the sparsely reported HfZrNbMo. The alloys were modeled as 128-atom special quasi-random structures and fully relaxed using density functional theory (DFT). Two complementary descriptors were evaluated from the relaxed geometries using a consistently defined reference lattice: a displacement-based metric derived from atomic off-site displacements and a shell-resolved bond length broadening metric for the first and second coordination shells. The resulting LLD descriptors have the lowest values for NbTaTiV, intermediate values for TiZrNbMo, and the highest for HfZrNbMo. Element-resolved analysis shows that individual species contribute differently to the overall distortion, information that is not captured by global descriptors alone. The pretrained MACE machine learning interatomic potential is assessed as a pre-relaxation step prior to DFT relaxation, as well as for screening candidate lattice parameters for HfZrNbMo. Full article

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11 pages, 318 KB

Open AccessArticle

Field Form of the Dynamics of Classical Many- and Few-Body Systems: From Microscopic Dynamics to Kinetics, Thermodynamics and Synergetics

by Anatoly Yu. Zakharov

Quantum Rep. 2022, 4(4), 533-543; https://doi.org/10.3390/quantum4040038 - 20 Nov 2022

Cited by 2 | Viewed by 2769

Abstract

A method is proposed for describing the dynamics of systems of interacting particles in terms of an auxiliary field, which in the static mode is equivalent to given interatomic potentials, and in the dynamic mode is a classical relativistic composite field. It is established that for interatomic potentials, the Fourier transform of which is a rational algebraic function of the wave vector, the auxiliary field is a composition of elementary fields that satisfy the Klein-Gordon equation with complex masses. The interaction between particles carried by the auxiliary field is nonlocal both in space variables and in time. The temporal non-locality is due to the dynamic nature of the auxiliary field and can be described in terms of functional-differential equations of retarded type. Due to the finiteness mass of the auxiliary field, the delay in interactions between particles can be arbitrarily large. A qualitative analysis of the dynamics of few-body and many-body systems with retarded interactions has been carried out, and a non-statistical mechanisms for both the thermodynamic behavior of systems and synergistic effects has been established. Full article

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16 pages, 3829 KB

Open AccessArticle

Atomistic Assessment of Solute-Solute Interactions during Grain Boundary Segregation

by Thomas P. Matson and Christopher A. Schuh

Nanomaterials 2021, 11(9), 2360; https://doi.org/10.3390/nano11092360 - 11 Sep 2021

Cited by 28 | Viewed by 4628

Abstract

Grain boundary solute segregation is becoming increasingly common as a means of stabilizing nanocrystalline alloys. Thermodynamic models for grain boundary segregation have recently revealed the need for spectral information, i.e., the full distribution of environments available at the grain boundary during segregation, in order to capture the essential physics of the problem for complex systems like nanocrystalline materials. However, there has been only one proposed method of extending spectral segregation models beyond the dilute limit, and it is based on simple, fitted parameters that are not atomistically informed. In this work, we present a physically motived atomistic method to measure the full distribution of solute-solute interaction energies at the grain boundaries in a polycrystalline environment. We then cast the results into a simple thermodynamic model, analyze the Al(Mg) system as a case study, and demonstrate strong agreement with physically rigorous hybrid Monte Carlo/molecular statics simulations. This approach provides a means of rapidly measuring key interactions for non-dilute grain boundary segregation for any system with an interatomic potential. Full article

(This article belongs to the Special Issue Thermal, Mechanical and Radiation Stability of Nanostructured Metals)

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14 pages, 2155 KB

Open AccessArticle

Transferability of Molecular Potentials for 2D Molybdenum Disulphide

by Marcin Maździarz

Materials 2021, 14(3), 519; https://doi.org/10.3390/ma14030519 - 21 Jan 2021

Cited by 13 | Viewed by 3653

Abstract

An ability of different molecular potentials to reproduce the properties of 2D molybdenum disulphide polymorphs is examined. Structural and mechanical properties, as well as phonon dispersion of the 1H, 1T and 1T’ single-layer MoS

_{2}

(SL MoS

_{2}

) phases, were obtained using [...] Read more.

_{2}

(SL MoS

_{2}

) phases, were obtained using density functional theory (DFT) and molecular statics calculations (MS) with Stillinger-Weber, REBO, SNAP and ReaxFF interatomic potentials. Quantitative systematic comparison and discussion of the results obtained are reported. Full article

(This article belongs to the Special Issue Computational Modelling and Design of Novel Engineering Materials)

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16 pages, 5799 KB

Open AccessEditor’s ChoiceArticle

Structure-Property Relationships of 2D Ga/In Chalcogenides

by Pingping Jiang, Pascal Boulet and Marie-Christine Record

Nanomaterials 2020, 10(11), 2188; https://doi.org/10.3390/nano10112188 - 2 Nov 2020

Cited by 4 | Viewed by 2969

Abstract

Two-dimensional MX (M = Ga, In; X = S, Se, Te) homo- and heterostructures are of interest in electronics and optoelectronics. Structural, electronic and optical properties of bulk and layered MX and GaX/InX heterostructures have been investigated comprehensively using density functional theory (DFT) calculations. Based on the quantum theory of atoms in molecules, topological analyses of bond degree (BD), bond length (BL) and bond angle (BA) have been detailed for interpreting interatomic interactions, hence the structure–property relationship. The X–X BD correlates linearly with the ratio of local potential and kinetic energy, and decreases as X goes from S to Te. For van der Waals (vdW) homo- and heterostructures of GaX and InX, a cubic relationship between microscopic interatomic interaction and macroscopic electromagnetic behavior has been established firstly relating to weighted absolute BD summation and static dielectric constant. A decisive role of vdW interaction in layer-dependent properties has been identified. The GaX/InX heterostructures have bandgaps in the range 0.23–1.49 eV, absorption coefficients over 10⁻⁵ cm⁻¹ and maximum conversion efficiency over 27%. Under strain, discordant BD evolutions are responsible for the exclusively distributed electrons and holes in sublayers of GaX/InX. Meanwhile, the interlayer BA adjustment with lattice mismatch explains the constraint-free lattice of the vdW heterostructure. Full article

(This article belongs to the Special Issue 2D Materials and Their Heterostructures and Superlattices)

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