arXiv subjects

I. Dabo

Publications and source records attributed to I. Dabo.

5 recordsLinked to original sources

arXiv2026

Unified Mapping of Multi-Site Electrocatalytic Activity Using a Single Descriptor

We present a precise and general method to map the activity of electrocatalysts across multiple sites. Starting from a mean-field statistical mechanics model, we introduce an effective adsorption free energy descriptor that explicitly incorporates lateral adsorbate-adsorbate interactions, enabling the construction of coverage-consistent volcano relationships. Extending this approach, we show that adsorption energetics and interaction strength define a two-dimensional activity landscape that gives rise to a "volcano ridge" that captures the coupled influence of binding and interactions on catalytic performance. For multi-site systems, we demonstrate that the inherently nonlinear coupling between distinct adsorption environments leads to multi-peaked activity trends that cannot be represented by conventional single-site descriptors. To address this, we introduce a reduced descriptor mapping that projects the multidimensional activity landscape onto a single effective coordinate while preserving the underlying physics of site heterogeneity and lateral interactions. The resulting framework generalizes Sabatier-type analysis to complex alloy catalysts and provides a physically interpretable route for screening electrocatalytic materials of arbitrary compositional complexity.

cond-mat.mtrl-sci↗

arXiv2023

Cluster expansion by transfer learning for phase stability predictions

Recent progress towards universal machine-learned interatomic potentials holds considerable promise for materials discovery. Yet the accuracy of these potentials for predicting phase stability may still be limited. In contrast, cluster expansions provide accurate phase stability predictions but are computationally demanding to parameterize from first principles, especially for structures of low dimension or with a large number of components, such as interfaces or multimetal catalysts. We overcome this trade-off via transfer learning. Using Bayesian inference, we incorporate prior statistical knowledge from machine-learned and physics-based potentials, enabling us to sample the most informative configurations and to efficiently fit first-principles cluster expansions. This algorithm is tested on Pt:Ni, showing robust convergence of the mixing energies as a function of sample size with reduced statistical fluctuations.

cond-mat.mtrl-sci↗

arXiv2010

Towards First-principles Electrochemistry

Chemisorbed molecules at a fuel cell electrode are a very sensitive probe of the surrounding electrochemical environment, and one that can be accurately monitored with different spectroscopic techniques. We develop a comprehensive electrochemical model to study molecular chemisorption at either constant charge or fixed applied voltage, and calculate from first principles the voltage dependence of vibrational frequencies -- the vibrational Stark effect -- for CO adsorbed on close-packed platinum electrodes. The predicted vibrational Stark slopes are found to be in very good agreement with experimental electrochemical spectroscopy data, thereby resolving previous controversies in the quantitative interpretation of in-situ experiments and elucidating the relation between canonical and grand-canonicaldescriptions of vibrational surface phenomena.

cond-mat.mtrl-sci↗

arXiv2009

Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials

Quantum ESPRESSO is an integrated suite of computer codes for electronic-structure calculations and materials modeling, based on density-functional theory, plane waves, and pseudopotentials (norm-conserving, ultrasoft, and projector-augmented wave). Quantum ESPRESSO stands for "opEn Source Package for Research in Electronic Structure, Simulation, and Optimization". It is freely available to researchers around the world under the terms of the GNU General Public License. Quantum ESPRESSO builds upon newly-restructured electronic-structure codes that have been developed and tested by some of the original authors of novel electronic-structure algorithms and applied in the last twenty years by some of the leading materials modeling groups worldwide. Innovation and efficiency are still its main focus, with special attention paid to massively-parallel architectures, and a great effort being devoted to user friendliness. Quantum ESPRESSO is evolving towards a distribution of independent and inter-operable codes in the spirit of an open-source project, where researchers active in the field of electronic-structure calculations are encouraged to participate in the project by contributing their own codes or by implementing their own ideas into existing codes.

cond-mat.mtrl-sci↗

arXiv2009

Non-Koopmans Corrections in Density-functional Theory: Self-interaction Revisited

In effective single-electron theories, self-interaction manifests itself through the unphysical dependence of the energy of an electronic state as a function of its occupation, which results in important deviations from the ideal Koopmans trend and strongly affects the accuracy of electronic-structure predictions. Here, we study the non-Koopmans behavior of local and semilocal density-functional theory (DFT) total energy methods as a means to quantify and to correct self-interaction errors. We introduce a non-Koopmans self-interaction correction that generalizes the Perdew-Zunger scheme, and demonstrate its considerably improved performance in correcting the deficiencies of DFT approximations for self-interaction problems of fundamental and practical relevance.

cond-mat.mtrl-sci↗