Highlights

EPFL researchers make theoretical breakthrough in thermoelectric material to better harness waste heat for sustainable energy.

The collection of 2D materials, first initiated  in 2018, has been expanded with 1,252 new monolayers that could be exfoliated from existing tridimensional structures.

A new study by Berend Smit’s group at EPFL introduces a new computational framework that allows to screen large numbers of Covalent Organic Frameworks (COFs) in a fast and efficient way, to pre-select the best candidates for specific photocatalytic applications, such as water splitting. Starting from a set of 419 COFs for which there are reported experiments, the workflow allowed the selection of 13 candidate materials for water splitting. 

Quantum computing holds great promises for computational material science. A new project added to NCCR MARVEL at the beginning of Phase III wants to explore the potential of the current generation of hybrid systems - that combine a classical machine with a quantum one – for the simulation of electronic structures. Project leader Giuseppe Carleo explains how the group will develop new algorithms and novel machine learning strategies to run on these machines and improve the accuracy of current modelling methods. “The classical part does the heavy lifting and brings you very close to the exact solution," he explains, "and then you hope the quantum part gives you the extra step to reach the final accuracy".

A new method developed by the NCCR MARVEL laboratory of Michele Ceriotti at EPFL allows modelling alloys containing up to 25 transition metals, matching a remarkable accuracy with a manageable requirement of data and computational resources. The group validated the model and used it for computational experiments on three representative alloy compositions. In the future the model will be expanded to predict the catalytic behaviour of the surfaces of high-entropy alloys.

A new method developed by the NCCR MARVEL laboratory of Michele Ceriotti at EPFL allows modelling alloys containing up to 25 transition metals, matching a remarkable accuracy with a manageable requirement of data and computational resources. The group validated the model and used it for computational experiments on three representative alloy compositions. In the future the model will be expanded to predict the catalytic behaviour of the surfaces of high-entropy alloys.

NCCR MARVEL researchers have applied DFT with extended Hubbard functionals (DFT+U+V) to the study of two candidate cathode materials belonging to the class of lithium-manganese-oxide spinels. They used a new approach to determine the Hubbard U and V parameters entirely from first principles and found that the method accurately predicts the geometrical properties, oxidation states, band gaps, and voltages of the two materials. The article was included in the "2023 PCCP HOT Articles" collection.

Researchers including NCCR MARVEL’s Professor Ana Akrap at the Department of Physics at the University of Fribourg used Landau-level spectroscopy to determine the temperature dependence of the energy band gap in zirconium pentatelluride (ZrTe5). They found that the band gap is non-zero at low temperatures and increases monotonically when the temperature is raised, adding to evidence that ZrTe5 is a weak topological insulator. 

An ETHZ team led by Prof. Sereina Riniker, Associate Professor of Computational Chemistry at the Department of Chemistry and Applied Biosciences, has developed an alternative strategy for parametrizing intermolecular interactions. Described in the paper “Regularized by Physics: Graph Neural Network Parametrized Potentials for the Description of Intermolecular Interactions,” recently published in the Journal of Chemical Theory and Computation, the approach accelerates and simplifies the parametrization process of classical force fields and can take advantage of large data sets. Used in combination with machine learning-based techniques, the model allows researchers to take advantage of the best of both, and access a universal optimization toolkit combined with robust and physically constrained models.

NCCR MARVEL researchers have applied for the first time first-principles molecular dynamics with the Parrinello-Rahman method to characterize the elastic properties of superionic conductors. Their study highlights the importance of the quasi-liquid dynamics of the Li ions in the elastic response, and showcases a significant softening of the predicted moduli compared to previous static approaches. The approach, complemented with the computation of the statistical errors, provides accurate information and reference results for the elastic constants and moduli of three benchmark oxide and sulfide solid-state electrolytes, and paves the way for a better understanding of the mechanical properties of the materials that may be used in the next generation of solid-state-battery technologies.

Prof. William Curtin, leader of NCCR MARVEL’s Pillar 1, Design and Discovery of Novel Materials and member of the executive committee and colleagues including Dr. Christian Leinenbach, Head of the Advanced Processing & Additive Manufacturing of Metals at Empa have used theories and expanded thermodynamic tools to sift through a huge materials space to identify high entropy alloys that satisfy a range of necessary performance properties. They validated the approach against data from recent literature, identified a promising new material, fabricated it at Empa, and then confirmed several predicted properties through experiment. The method is general and can be adapted to to other performance requirements, making it a reliable and efficient means of discovery for the next generation of high-temperature alloys. 

NCCR MARVEL’s Michele Ceriotti, EPFL professor and head of the School of Engineering’s Laboratory of Computational Science and Modelling, has published a perspective, “Beyond potentials: Integrated machine learning models for materials,” in the October edition of the MSR Bulletin.