Pinku Nath

An efficient and accurate framework for calculating lattice thermal conductivity of solids: AFLOW—AAPL Automatic Anharmonic Phonon Library

One of the most accurate approaches for calculating lattice thermal conductivity,

High-throughput prediction of finite-temperature properties using the quasi-harmonic approximation

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Spinodal Superlattices of Topological Insulators

DMPSID=1, is solving the Boltzmann transport equation starting from third-order anharmonic force constants. In addition to the underlying approximations of ab-initio parameterization, two main challenges are associated with this path: high computational costs and lack of automation in the frameworks using this methodology, which affect the discovery rate of novel materials with ad-hoc properties. Here, the Automatic Anharmonic Phonon Library (AAPL) is presented. It efficiently computes interatomic force constants by making effective use of crystal symmetry analysis, it solves the Boltzmann transport equation to obtain

AFLOW-QHA3P: Robust and automated method to compute thermodynamic properties of solids

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Engineering the electronic properties of topological insulator heterostructures

DMPSID=2, and allows a fully integrated operation with minimum user intervention, a rational addition to the current high-throughput accelerated materials development framework AFLOW. An “experiment vs. theory” study of the approach is shown, comparing accuracy and speed with respect to other available packages, and for materials characterized by strong electron localization and correlation. Combining AAPL with the pseudo-hybrid functional ACBN0 is possible to improve accuracy without increasing computational requirements.Thermal conductivity: Framework for calculating heat flow in solidsA new theoretical framework could provide a more efficient method for calculating a material’s thermal conductivity. Understanding how materials conduct heat is crucial for a range of applications, from heat sinks to thermal insulation. Despite its fundamental importance, predicting a material’s lattice thermal conductivity is challenging, and often requires experimental data or knowledge of specific properties to be entered during the process. An international team of researchers led by Stefano Curtarolo from Duke University now present a framework that can predict the lattice thermal conductivity of single-crystal and polycrystalline materials using just a single input file, with no further intervention. Called the Automatic Anharmonic Phonon Library, the methods computes certain parameters using symmetry analysis, before solving the Boltzmann transport equation, providing information on both the electronic structure and phonon-dependent properties.

Strong negative thermal expansion in metal carbides using the quasi-harmonic approximation

High-throughput ab initio calculations, cluster expansion techniques, and thermodynamic modeling have been synergistically combined to characterize the binodal and the spinodal decompositions features in the pseudo-binary lead chalcogenides PbSe-PbTe, PbS-PbTe, and PbS-PbSe. While our results agree with the available experimental data, our consolute temperatures substantially improve with respect to previous computational modeling. The computed phase diagrams corroborate that in ad hoc synthesis conditions the formation of nanostructure may occur justifying the low thermal conductivities in these alloys. The presented approach, making a rational use of online quantum repositories, can be extended to study thermodynamical and kinetic properties of materials of technological interest.