The energy landscapes and electronic properties of non-polar and polar nanofilms of silicon carbide are studied using periodic hybrid density functional calculations. Relative energies and electronic properties are reported as a function of film thickness for a set of structures derived from those of wurtzite, zinc blende and graphite. The energy landscape of the films is complex with pronounced nano-polymorphism. Across polar films different mechanisms in different cases remove or reduce the dipole moment, including charge transfer and phase transitions to the graphitic-like structures which are stable for the thinnest films. Graphitic structures are lowest in energy for the thinnest films. For ten layers non-polar films-zinc blende (110) and wurtzite(101-0) with tetrahedrally-coordinated Si and C in Si3C3rings in chair conformations-are lowest in energy, followed, ≈0.1 eV per formula unit higher in energy, by a body-centered tetragonal structure containing Si3C3rings in boat conformations. In the planar graphene structure the energy of the anti-site defect CSi-SiC(≈0.3 eV)) is more than an order of magnitude lower than in the bulk, suggesting a much higher degree of disorder in such films. One staggered graphitic-like structure with ABC stacking, a local minimum in the energy landscape, is of particular interest, since it lies in a regime of uncompensated polarity and possesses a direct band gap that decreases linearly with film thickness., from ≈2 eV (3 layers) to zero (6 layers).

Exploring quantum frontiers in protein structure prediction: techniques, challenges, and opportunities.

From the arrival of the SARS-CoV-2 coronavirus in 2019 and its associated COVID-19 pandemic, worldwide efforts have been focused on developing a drug to treat patients. The SARS-CoV-2 main protease (Mpro) is one of the main targets for drug design due to its key role in the virus replication and its distinguished ability to cleave peptides after a glutamine residue. Inspired by the knowledge of the inhibition mechanism of 20S Proteasome, this work focuses on exploring the inhibition process of SARS-CoV-2 Mpro with a β-lactone, as well as the impact of the stereochemistry of this compound on the stability of the enzyme:inhibitor binding formation complex. Based on molecular dynamics simulations with classical and hybrid QM/MM potentials, the free energy landscape of the mechanism of the formation of the covalent complex has been computed. The results show how one of the stereoisomers of the β-lactone derivative forms a stable reactant non-covalent complex in the active site of Mpro. Analysis of the kinetics and thermodynamics of the inhibition process suggests that this non-peptidyl compound can be considered a lead compound for future developments of efficient therapeutic compounds to treat patients with COVID-19.

This work reports the synthesis, characterization and study of the photophysical properties of two families of cyclometalated [Pt(C^N)(P^P)]X [C^N = 2-phenylbenzothiazolate (pbt), 1-phenylisoquinolinate (piq)] complexes. This study establishes structure-property relationships across variations in the C^N ligand (pbt vs. piq), the diphosphine backbone [P^P = 1,2-bis(diphenylphosphino)benzene (dppbz), 2,3-bis(diphenylphosphino)pyrazine (dpppyz), 2,2'-bis(diphenylphosphino)-1,1'-binaphthalene (BINAP) and bis[2-(diphenylphosphino)phenyl]ether (DPEphos), and the counteranion [X = PF6-, NO3-, [Al(ORF)4]-]. Single-crystal X-ray diffraction reveals well-defined trends in coordination geometry, with wide-bite-angle diphosphines inducing pronounced distortions that correlate with weakened emissive behaviour. The photophysical study shows that the nature of the C^N ligand predominantly governs the excited-state energy landscape: pbt complexes emit in the yellow region with high efficiencies, whereas the more conjugated piq derivatives display red-shifted phosphorescence with longer emission lifetimes. In solution, several complexes exhibit dual fluorescence-phosphorescence emission. All complexes (except 5) act as efficient triplet sensitizers. Guided by their increased photophysical stability and higher solubility, two Krossing-type anion [Al(ORF)4]- based salts were selected as catalysts for the photooxidation of p-bromothioanisole under homogeneous conditions. While the pbt derivative shows limited activity, due to catalyst degradation under near-UV irradiation, the piq analogue operates efficiently under mild blue-light excitation (460 nm), achieving 100% conversion with only 1% catalyst loading in 9 hours.

Terracettes, striking, step-like landforms that stripe steep, vegetated hillslopes, have puzzled scientists for more than a century. Competing hypotheses invoke either slow mass wasting (gravity-driven soil flow) or the relentless trampling of grazing animals, yet no mechanistic model has linked hoof-scale behaviour to landscape-scale form. Here, we bridge that gap with an active-walker model in which ungulates are represented as stochastic foragers moving on an erodible slope. Each agent weighs the energetic cost of climbing against the benefit of fresh forage; every hoof-fall compacts soil and lowers local biomass, subtly reshaping the energy landscape that guides subsequent steps. Over time, these stigmergic feedbacks concentrate traffic along cross-slope paths, which coalesce into periodic tread-and-riser bands morphologically analogous to natural terracettes. Our model illustrates how local foraging rules governing movement and substrate feedback can self-organize into large-scale topographic patterns, highlighting the wider role of decentralized biological processes in sculpting terrestrial landscapes.

Owing to the possession of naturally formed quantum wells with strong spatial and dielectric confinements, 2D lead-halide perovskites are attracting intensive research interest in the context of potential applications in classical optoelectronic devices. Here we have synthesized a 2D (PEA)2PbI4 perovskite microplate and observed at ∼3 K that it can emit single photons from the abundant ultranarrow peaks appearing in the photoluminescence spectrum. This signifies the formation of 0D quantum emitters within the otherwise homogeneous 2D energy landscape, which can be attributed to the thickness fluctuations induced by octahedral tiltings across an inorganic sheet. These findings mark the emergence of a hybrid type of quantum emitters with both 0D and 2D confinements, thus extending the fundamental and practical studies of 2D perovskites to the prospective regime of quantum information technologies.

Dynamic molecular crystals capable of undergoing cooperative structural transformations offer exciting prospects for next-generation actuators, sensors, and stimuli-responsive materials. However, realizing large-scale deformation in the solid state─particularly through torsional mechanisms─remains rare. Here, we examine a cyanostilbene derivative, αDDDCS, that exhibits solid-state twist elasticity enabled by cooperative conformational torsion and packing motif conversion. This system features three enantiotropic polymorphs that interconvert through thermoelastic and mechanosalient phase transitions, reflecting a competition between thermodynamic stability and kinetic accessibility, including a Y → C thermoelastic transformation involving a 27% lattice elongation─among the largest reported to date. Single-crystal X-ray diffraction, variable-temperature characterization, and quantum chemical calculations reveal that the transformation proceeds through a π-stacking-to-μ-herringbone transition, governed by a distinct torsional barrier and polymorph-specific free energy landscape. Remarkably, this is the first demonstration of twist elasticity accessed via mechanosalient actuation. Our findings establish conformational twist as a viable molecular design element for achieving high-strain responsiveness in dynamic crystals.

While high-entropy perovskite oxides have recently emerged as promising hosts for exsolution-enabled catalysts and electrodes, a systematic understanding of how high-entropy compositions influence exsolution remains limited. Here, we compare Ni exsolution in a simpler perovskite oxide, (La0.6Sr0.4)0.95(Co0.19Fe0.76Ni0.05)O3-δ (LSCF-5Ni), and two high-entropy perovskite oxides, (La0.2Sr0.2Ca0.2Nd0.2Y0.2)0.95(Co0.19Fe0.76Ni0.05)O3-δ (CaNdY-5Ni) and (La0.2Sr0.2Ba0.2Nd0.2Y0.2)0.95(Co0.19Fe0.76Ni0.05)O3-δ (BaNdY-5Ni). The experiment reveals that the exsolved nanoparticle number density follows the order LSCF-5Ni < CaNdY-5Ni < BaNdY-5Ni, demonstrating that high-entropy configurations can enhance exsolution. To understand this trend, we develop a Monte Carlo-based modeling framework that combines a machine-learned interatomic potential to simulate representative atomic configurations and statistically evaluate possible exsolution pathways. The results show that high-entropy configurations with greater variations in A-site cation sizes (and thus greater lattice distortions) can broaden distributions of Ni migration and reduction energies, thereby creating more thermodynamically favorable exsolution pathways.

Female genital tuberculosis (FGTB) often remains untreated because many patients show no clear symptoms or present with vague clinical symptoms. Poor reproductive outcomes and prolonged treatment are usually the results of this delay in detection. Current TB therapies are costly and toxic, especially for strains of the disease that are resistant to several drugs. These drawbacks highlight the urgent need for safer and more effective treatment options. Computational drug discovery approaches targeting uterine TB remain limited, and essential pathogen-specific proteins non-homologous to humans are underexplored. This work identified GMP synthase as an important and specific target in Mycobacterium tuberculosis using subtractive genomics and drug repurposing. To improve specificity, targets that are similar to commensal and human proteins were discarded. 2619 FDA-approved drugs were virtually screened, and probenecid was found to be a probable choice. Quantum chemical analysis confirmed the robust binding and stable interactions of probenecid with the target. Molecular dynamics simulations and RMSD- Rg -based- Free Energy Landscape (FEL), along with PCA- based- Free Energy Landscape (FEL), confirmed the stability of the protein-ligand complex, and molecular docking identified favorable binding patterns. Probenecid inhibited M. tuberculosis H37Rv at a minimum inhibitory concentration (MIC) of 50µg/mL, according to in vitro studies, while isoniazid and rifampicin had MICs of 0.20µg/mL and 0.25µg/mL, respectively. However, Probenecid's well-established safety profile and pharmacokinetic characteristics indicate that localized administration via a liposomal vaginal formulation may achieve therapeutic concentrations at the infection site while lowering systemic exposure, even though it is less effective than first-line medications. Future study will focus on mucosal safety, local pharmacokinetics, and formulation development. Overall, our findings highlight the usefulness of combining subtractive genomics, computational modeling, and experimental validation in tuberculosis drug discovery and indicate the possibility of repurposing probenecid for FGTB.

In recent decades, the world has faced successive energy crises that have highlighted the fragility of generation and distribution systems across both developing and advanced economies. Given this scenario, coupled with accelerated urbanisation, a review of urban energy consumption, generation and management systems is indispensable. The energy indicators defined in the Brazilian standard NBR ISO 37120, which addresses service performance and quality of life in cities, were analysed, focusing on the energy sustainability of municipalities in the Brazilian state of Goiás. Data from 2019 to 2023 were systematised, and critical and comparative analyses were performed to identify trends, regional inequalities and opportunities for improvement in municipal energy management. To enable visualisation and interpretation of results, an interactive tool was developed and implemented in Power BI, allowing public managers to understand the local energy landscape and support strategic decision making. This study contributes to strengthening energy planning capacities and to formulating more effective and sustainable public policies aligned with the UN Sustainable Development Goals.

Mechanically induced conformational switching at the single-molecule level represents a fundamental mechanism for molecular functionality, yet quantitative characterization of the underlying force and energy landscape remains limited. Here, we study individual TBrPP-Co(II) molecules on Au(111) using qPlus atomic force microscopy. By reconstructing interaction potentials from 3D Δf(x,y,z) data, we determine a threshold force of ∼96 ± 8 pN and a tip-induced switching interaction energy of ∼38 ± 4 meV associate with the conformational transition. The isolated tip-molecule force follows a power law (exponent ∼6), indicating dominance of long-range van der Waals interactions. At closer distances, deviations reveal force-induced deformation preceding the transition. Validation via the inflection point test confirms measurement reliability. These findings show that long-range dispersive interactions can mechanically deform a molecule and facilitate conformational switching through a deformation-assisted pathway, providing a quantitative framework for controlling mechanically driven functionality at the single-molecule scale.

Softer means stickier for solid adhesives, because material compliance facilitates close contact between nonconformal surfaces. Recent discoveries have revealed that soft materials can exhibit a rich array of new physics arising from competing effects of continuum elasticity, fluid-like surface mechanics, and internal poroelastic flows, all of which can directly impact interfacial interactions. In this work, we investigate this complex interplay across several orders of magnitude of elastic stiffness by measuring the complete adhesive contact geometry between compliant silicone gel microspheres and flat, rigid substrates. We observe a continuous elastocapillary transition in adhesion mechanics, revealed by both the breadth of data and the detailed contact geometries. Importantly, soft gel spheres exhibit a remarkably broad range of near-equilibrium contact morphologies and their contact line deformation is always mediated by a fluid contact zone that phase separates from the gel. To explain this, we develop a model incorporating elastocapillary and poroelastic mechanics that predicts the complete range of adhesive behavior and elucidates energetic tradeoffs. The data and model together reveal a shallow energy landscape that may contribute to the robustness of everyday adhesives.

Switchable polarization makes ferroelectrics a critical component in memories, actuators, and electro-optic devices, and potential candidates for nanoelectronics. A strain-induced preferential 90° polarization switching in ferroelectric oxides is highly desirable for achieving enhanced electromechanical response. However, such strain-induced switching typically proceeds along random paths under tensile strain in two opposite directions, which is unfavorable for electromechanical device performance. Here, we propose a strategy that leverages miscut-angle-driven in-plane symmetry breaking to preferentially control the 90° polarization switching path in freestanding PbTiO3 (PTO) films under uniaxial strain. Theoretical calculations highlight the key role of miscut substrates in manipulating the energy landscape during strain engineering. A combination of in situ X-ray diffraction and vector piezo-response force microscopy measurements directly reveals that preferential 90° polarization switching can be achieved by engineering in-plane symmetry. This work establishes design principles for controlling 90° polarization switching paths in freestanding ferroelectric oxides for high-performance electromechanical devices.

The Na+/Ca2+ exchanger (NCX) is a membrane protein that couples the downhill transport of Na+ across the plasma membrane to the uphill movement of Ca2+ in the opposite direction. The NCX is a key Ca2+ extrusion mechanism in excitable cells. It contains a transmembrane domain that catalyzes the counter-transport of Na+ and Ca2+, and a large intracellular loop (IL) that is responsible for the allosteric regulation of the exchanger by its substrates. The NCX intracellular loop contains a two-domain Ca2+-sensor, CBD12, which harbors Ca2+ regulatory sites. Ca2+-binding to CBD12 triggers NCX activation and alleviates Na+-dependent inactivation. An outstanding question in this field is how Ca2+-binding to CBD12 activates the exchanger? Previous experimental studies showed that CBD12 displays considerable interdomain flexibility in the unbound state, while Ca2+ binding near the linker between the two domains stabilizes a rigid and widely opened interdomain conformation. This phenomenon could be an important step in the Ca2+ regulation mechanism. Using the Drosophila exchanger, CALX, as a model system, we carried out coarse-grained molecular dynamics simulations using a dual-basin structure-based model (SBM) to sample large-scale conformational transitions between open and closed states. In addition, we calculated the CBD12 free energy profile along the open-closed transition coordinate, in the Ca2+-bound and in the free states. We found that Ca2+ binding reshapes the CBD12 free energy landscape, stabilizing a widely opened interdomain conformation in agreement with previously published experimental data. Notably, the energy landscape of the two CALX CBD12 isoforms, which differ by only five amino acids near the interdomain linker, is substantially different. These results provide atomistic insights into the open-closed conformational transition experienced by this two-domain construct, and are consistent with the considerable broadening of the solution NMR resonances of CBD12 1.2 in comparison with the 1.1 isoform.

Single adatoms units supported by two-dimensional materials offer an appealing platform for atomic scale state control, but any memory-related interpretation requires distinguishable metastable states, a realistic retention assessment, and a clear readout mechanism. Here, based on first-principles calculations, we systematically screen 29 transition-metal adatoms on monolayer MoS2 and identify seven elements that exhibit intrinsic out-of-plane conformational bistability. Fe is selected as a prototype because it possesses two well-defined adsorption states with distinct vertical heights separated by a finite zero-field barrier. The operative bistable coordinate is the adsorption height of the Fe atom rather than a magnetic order parameter of the MoS2 substrate. The two structural branches also exhibit different localized spin-polarization responses: the low adsorption state shows an opposite induced spin-polarization on the nearest Mo/S environment, whereas the high adsorption state shows a predominantly parallel local response. Electronic-structure analysis reveals that this behavior originates from adsorption-height-dependent Fe-substrate interaction: the low state is characterized by stronger Fe-3d-S-3p/Mo-4d hybridization and bonding stabilization, whereas the high state is accompanied by weakened p-d hybridization and the occupation of an Fe-4s-related antibonding state. Additional field-dependent NEB calculations show that an out-of-plane electric field reshapes the double-well energy landscape and lowers the vertical switching barrier, while lateral migration remains less favorable for the pristine model considered here. Local harmonic vibrational analysis and HTST estimates further show that the bistable states can be kinetically stable at low temperature, but the present barriers are insufficient for long-term room-temperature nonvolatile retention. These results establish Fe@MoS2 as a local-field-controllable conformationally bistable single-atom system with an adsorption-height-dependent local magnetic response.

The structural prediction of metal nanoclusters is hindered by the extremely complex potential energy surface and the prohibitive cost of first-principles calculations. Here, we develop an efficient structure-prediction framework that tightly integrates machine-learning interatomic potentials with global optimization. Neural network atomic potentials are iteratively trained to achieve density-functional-theory accuracy and coupled with a genetic algorithm to enable reliable exploration of complex energy landscapes. As a stringent benchmark, the framework is applied to neutral Aun clusters (n = 30-45), where it robustly identifies low-energy structures at an affordable computational cost and reveals a non-monotonic structural evolution from hollow cage-like motifs to multi-core-cage building blocks over a critical size range. Notably, this transition exhibits pronounced differences from that of the corresponding anionic clusters, highlighting the potential of the proposed active-learning workflow as an extensible strategy for investigating metal clusters with complex electronic structures.

The dramatic slowdown of dynamics in deeply supercooled liquids remains a central problem in condensed matter physics, chemistry, and materials science. Within the inherent-structure framework, structural relaxation may be viewed as activated transitions between basins of the potential energy landscape via high-energy bottleneck configurations. The intermediate state can be modeled as a transient entropy droplet, representing a locally reconfigured region embedded in an amorphous solid, whose formation is driven by configurational entropy and opposed by elastic mismatch with the surrounding matrix. In this study, we develop an elasticity-based theory for the activation free energy associated with the formation of such a droplet. By incorporating intrinsic elastic heterogeneity and non-affine strain redistribution, we show that the mismatch energy is reduced through cooperative pathways involving softer regions of the material. This leads to an effective interfacial penalty that scales as R3/2 with droplet size, in contrast to the conventional R2 scaling expected for a homogeneous medium. The resulting free-energy balance yields activation barriers inversely proportional to the configurational entropy, thereby recovering the Adam-Gibbs relation for structural relaxation. While the same scaling is invoked in random first-order transition theory, it is derived here from elastic heterogeneity and non-affine deformation, providing a complementary mechanical interpretation of entropy-controlled dynamics in glassy systems.

ABSTRACT The Arctic archipelago of Svalbard is currently undergoing a profound energy transition, shifting from coal-based infrastructure towards a low-carbon hybrid energy system. Following the closure of the last coal mine in 2025, a range of renewable energy technologies is expected to be implemented in accordance with a new national energy plan. This article investigates the expectations that residents of Longyearbyen have for this socio-technical transformation, with particular attention to the roles of institutional trust, energy citizenship, identification with nature and climate change denialism. Drawing on survey data, the study identifies five distinct public expectation profiles regarding the renewable energy transition. Two of these – Risk and Unreliable – reflect deep-seated concerns, while three – Opportunities, Climate and Innovation – express more optimistic outlooks. The findings highlight institutional trust as a key predictor of optimistic expectations, often in conjunction with energy citizenship. In contrast, identification with Svalbard’s natural environment and climate change denialism are more strongly associated with the concerned profiles. While prior research has emphasized the importance of institutional trust in energy transitions, this study demonstrates how trust also shapes future-oriented expectations and operates in tandem with energy citizenship norms. The article concludes by outlining strategic opportunities for fostering inclusive community support and mitigating the risk of political polarization in Svalbard’s evolving energy landscape.

From microstates to macroscales: A critical review of maximum entropy modeling and energy landscape analysis in functional MRI.

Dynamic remodeling of USP28 by the selective inhibitor CAS-010: Insights from DFT and molecular dynamics simulations.