Optimized Crystallographic Graph Generation for Material Science

Graph neural networks are widely used in machine learning applied to chemistry, and in particular for material science discovery. For crystalline materials, however, generating graph-based representation from geometrical information for neural networks is not a trivial task. The periodicity of crystalline needs efficient implementations to be processed in real-time under a massively parallel environment. With the aim of training graph-based generative models of new material discovery, we propose an efficient tool to generate cutoff graphs and k-nearest-neighbours graphs of periodic structures within GPU optimization. We provide pyMatGraph a Pytorch-compatible framework to generate graphs in real-time during the training of neural network architecture. Our tool can update a graph of a structure, making generative models able to update the geometry and process the updated graph during the forward propagation on the GPU side. Our code is publicly available at https://github.com/aklipf/mat-graph

Investigating structure, magneto-electronic, and thermoelectric properties of the new d0 quaternary Heusler compounds RbCaCZ (Z = P, As, Sb) from first principle calculations

The ab initio calculations based on the density functional theory (DFT) using the self-consistent full potential linearized augmented plane wave (FPLAPW) method were performed to explore the electronic structures, magnetic and thermoelectric properties of quaternary alloys RbCaCZ (Z = P, As, Sb) with quaternary Heusler structure. Results showed that FM-Y3 is the most favorable atomic arrangement. All the compounds are found to be half-metallic ferromagnetic materials with an integer magnetic moment of 2.00 μB, which predominantly derives from the strong spin polarization of p channels of C hybridized with Z elements. The predicted minority (half-metallic) band gaps were found to be 1.86 (0.87), 1.72 (0.78), and 1.78 (0.71) eV for Z = P, As, and Sb, respectively. Thermoelectric properties of the RbCaCZ (Z = P, As, Sb) materials are additionally computed over an extensive variety of temperature and it is discovered that all compounds demonstrates higher figure of merit. The half-metallic structures of these compounds with large band gaps and adequate Seebeck coefficients mean that they are suitable for use in spintronic and thermoelectric device applications

Evolutionary Crystal Structure Prediction of new rich-Mg compounds

National audienc

Lithium intercalation effects on the V₂O₅ (001) surface

International audienceno abstrac

Prediction of new electrodes for hydrogen production : the meeting between Darwin and Schrödinger

National audienc

Theoretical investigation of binary systems for hydrogen storage

International audienceno abstrac

Density functional calculations of the structural, electronic, and ferroelectric properties of high‐ k titanate Re<inf>2</inf> Ti<inf>2</inf> O<inf>7</inf> (Re=La and Nd)

International audienceno abstrac

Molecular modeling of cyclodextrin inclusion complexes

International audienceCyclodextrins can form inclusion complexes with a wide range of guest molecules. Experimentally, it is often challenging to extract structural and dynamic information at the atomic scale about cyclodextrin inclusion complexes especially in the aqueous phase. This review summarized, through some examples, the different Molecular modeling techniques used to study the structure of cyclodextrin inclusion complexes

The effect of Biaxial strain on electronic properties of (SnO₂/TiO₂)_n superlattices

International audienc

New insight for hydrogen storage in the magnesium nickel and magne- sium copper systems

International audienc