Plutonium is a critically important material as the behavior of its $5f$ electrons stands midway between the metalliclike itinerant character of the light actinides and localized atomic-core-like character of the heavy actinides. The $\delta$ phase of plutonium ($\delta$-Pu), whereas still itinerant, has a large coherent Kondo peak and strong electronic correlations coming from its near-localized character. Using sophisticated Gutzwiller wave function and dynamical mean-field theory correlated theories, we study the Fermi surface and associated mass renormalizations of $\delta$-Pu together with calculations of the de Haas–van Alphen frequencies. We find a large ($\sim 200\%$) correlation induced volume expansion in both the hole and the electron pockets of the Fermi surface in addition to an intermediate mass enhancement. All of the correlated electron theories predict, approximately, the same hole pocket placement in the Brillouin zone, which is different from that obtained in conventional density-functional band-structure theory, whereas the electron pockets from all theories are in, roughly, the same place.

Using femtosecond time-resolved x-ray diffraction, we investigated optically excited coherent acoustic phonons in the Weyl semimetal TaAs. The low symmetry of the (112) surface probed in our experiment enables the simultaneous excitation of longitudinal and shear acoustic modes, whose dispersion closely matches our simulations. We observed an asymmetry in the spectral line shape of the longitudinal mode that is notably absent from the shear mode, suggesting a time-dependent frequency chirp that is likely driven by photoinduced carrier diffusion. We argue on the basis of symmetry that these acoustic deformations can transiently alter the electronic structure near the Weyl points and support this with model calculations. Our study underscores the benefit of using off-axis crystal orientations when optically exciting acoustic deformations in topological semimetals, allowing one to transiently change their crystal and electronic structures.

The phonon-induced renormalization of electronic band structures is investigated through first-principles calculations based on the density functional perturbation theory for nine materials with various crystal symmetries. Our results demonstrate that the magnitude of the zero-point renormalization (ZPR) of the electronic band structure is dependent on both crystal structure and material composition. We have performed analysis of the electron-phonon-coupling–induced renormalization for two silicon (Si) allotropes, three carbon (C) allotropes, and four boron nitride (BN) polymorphs. Phonon dispersions of each material were computed, and our analysis indicates that materials with optical phonons at higher maximum frequencies, such as graphite and hexagonal BN, have larger absolute ZPRs, with the exception of graphene, which has a considerably smaller ZPR despite having phonon frequencies in the same range as graphite. Depending on the structure and material, renormalizations can be comparable to the GW many-body corrections to Kohn-Sham eigenenergies and, thus, need to be considered in electronic structure calculations. The temperature dependence of the renormalizations is also considered, and in all materials, the eigenenergy renormalization at the band gap and around the Fermi level increases with increasing temperature.

Uranium mononitride (UN) is a promising accident-tolerant fuel because of its high fissile density and high thermal conductivity. In this study, we developed the first machine learning interatomic potentials for reliable atomic-scale modeling of UN at finite temperatures. We constructed a training set using density functional theory (DFT) calculations that was enriched through an active learning procedure, and two neural network potentials were generated. Both potentials successfully reproduce key thermophysical properties of interest, such as temperature-dependent lattice parameter, specific heat capacity, and bulk modulus. We also evaluated the energy of stoichiometric defect reactions and defect migration barriers and found close agreement with DFT predictions, demonstrating that our potentials can be used for modeling defects in UN. Additional tests provide evidence that our potentials are reliable for simulating diffusion, noble gas impurities, and radiation damage.

The electronic and magnetic structure of ${\mathrm{CrPS}}_4$, a two-dimensional (2D) magnetic semiconductor is examined by employing the SCAN meta-GGA density functional. We find the resulting magnetic moment and band gap are in excellent agreement with experiment. From the bulk magnetic configurations, we confirm the experimentally observed A-type antiferromagnetic (A-AFM) ordered ground state with a magnetic moment of $2.78{\mu }_{\mathrm{B}}$ per chromium atom and band gap of 1.34 eV. To gain insight into the evolution of the ground state with layers, the total energy of each magnetic configuration is calculated for a variety of thicknesses. Monolayer ${\mathrm{CrPS}}_4$ is predicted to be a ferromagnetic insulator with a band gap of 1.37 eV, and A-AFM for bilayer and trilayer, with band gaps of 1.35 and 1.30 eV, respectively. The electronic structure is reported for the single-, two-, and three-layer and bulk ${\mathrm{CrPS}}_4$. Finally, we explore the optical properties of the 2D structure and report the dielectric tensor components and Kerr parameters for the monolayer.

The impact of irradiation on the thermal and electronic properties of materials is a persistent puzzle, particularly defect formation at the atomic and nanoscales. This work examines the nanoscale effects of low‐energy irradiation on tungsten (W), focusing on defect‐induced modifications to thermal and electronic transport. Using the site‐projected thermal conductivity (SPTC) method [A. Gautam et al. PSS‐RRL, 2400306, 2024], bulk and twin‐grain boundary W with vacancy defects based on the Norgett–Robinson–Torrens displacements per atom model is analyzed. SPTC provides a detailed prediction of postcascade spatial thermal conductivity distribution. Electronic conductivity activity is estimated using the “ method” [K. Nepal et al. Carbon, 119711, 2025] to explore the consequences of vacancies and grain boundaries, highlighting the defect‐dependent nature of charge transport behavior. These findings offer high‐resolution insights into irradiation‐driven transport phenomena, with implications for space‐exposed materials and nanoscale thermal/electronic management.