Browse Articles

Measurement-efficient ADAPT-VQE with the SOAP parameter optimizer

Quantum computing on near-term noisy intermediate-scale quantum devices holds significant promise for simulating complex chemical systems. Among various variational quantum algorithms, the adaptive derivative-assembled pseudo-Trotter ansatz variational quantum eigensolver (ADAPT-VQE) is widely used for generating molecule-specific adaptive ansätze for different molecules, yet its measurement requirement is extensive, calling for suitable optimizers. In this study, we utilize the ADAPT-VQE algorithm enhanced by a powerful optimizer termed sequential optimization with an approximate parabola (SOAP) to calculate molecular energies. These computations are carried out through classical simulations using the TenCirChem software. Our results demonstrate the efficiency and robustness of the SOAP optimizer for ADAPT-VQE. Furthermore, we show that SOAP performs effectively across different ADAPT-VQE ansatz element pools. This work presents a strategy to mitigate the substantial measurement requirements associated with ADAPT-VQE.

Grid resilience enhancement of photovoltaic systems via Lyapunov-validated active–reactive power coordination and inverter oversizing

The Berry curvature in the framework of current density functional theory for molecules in external magnetic fields

In this work, we investigate the quantum geometry framework for molecules in external magnetic fields. For electronic ground states, the linear response formalism through which the quantum geometric tensor can be computed was described by Culpitt et al. [J. Chem. Phys. 156, 044121 (2022)], and this work expands their framework to current density functional theory. We show that for nuclear displacements, the Fubini–Study metric can be connected to the diagonal Born–Oppenheimer correction. Furthermore, we examine the effects of external magnetic fields on the molecular Berry curvature. For selected systems, we investigate how different density functional approximations compare to both full configuration interaction and Hartree–Fock theory. Finally, the convergence of the Berry curvature with respect to the numerical grid is estimated for different functionals, highlighting some known deficiencies of modern density functional approximations.

Molecular dynamics of water hexamer anions at cryogenic temperatures

We studied the dynamics of water hexamer anions [(H2O)6−] at cryoscopic temperatures using MP2 level ab initio molecular dynamics (AIMD) simulations. The vertical electron detachment energy (VDE) of these clusters varies in the 150–550 meV range in good agreement with experiments. The dominant characteristic pattern of the electron binding sites consists of a double hydrogen bond acceptor water molecule with two dangling hydrogen atoms in direct contact with the excess electron. In addition to surface localized excess electron clusters, we examine the dynamics of a hexamer model of the bulk hydrated electron. We analyze correlations between the binding strength of the excess electron and geometrical and spectroscopic properties, in particular, the radius of the excess electron and the bending frequencies of the electron binding water units. Our investigations were extended to the evaluation of nuclear quantum effects on the physical properties of the clusters by performing path integral molecular dynamics simulations on a neural network based potential energy surface and also using the generalized smoothed trajectory analysis method. Nuclear quantum effects at these low temperatures were found to be significant, as demonstrated by structural, energetic, and spectroscopic characteristics of the clusters. Most strikingly, the half-width of the quantum distributions of the VDE or the radius of the electron increases by a stunning factor of ∼5–10 relative to the classical ones. Molecular dynamics trajectories also reveal that, while all investigated isomers persist at 10 K in AIMD simulations, nuclear quantum effects promote isomerizations to more stable, lower lying minima.

Model driven adaptive design with concentration profiles

Effective kinetic models of heterogeneous catalytic processes are an indispensable tool for reactor design, optimization, and control. Under the assumption of using functional forms like power laws, model parameters are traditionally fitted to kinetic data measured along local line scans. A local line scan involves systematically varying one individual reaction parameter, such as a reactant concentration or temperature, at a time. This approach typically involves numerous separate kinetic measurements and is susceptible to the uncertainty of these line scans in determining the model’s parameters. Here, we explore the use of profile reactors in combination with a fully automated adaptive design approach for an efficient identification of effective kinetic models. Originally developed to provide operando information along the axis of tubular reactors, profile reactors provide a complex line scan that encapsulates kinetic information across all reaction conditions probed along the tube. The proposed Model-Driven Adaptive Design with Profiles algorithm harnesses this extensive dataset to strategically guide the selection of initial reaction conditions for subsequent profile reactor measurements. This approach ensures that each line scan provides maximally complementary information, thereby significantly enhancing the efficiency and accuracy of kinetic model identification.

Efficient calculation of crystal–solution coexistence lines for aqueous electrolytes

Electrolyte solutions have a widespread presence in biological, geological, and industrial systems. To advance our understanding of these solutions, we need to develop theoretical models that can efficiently predict their collective properties. In this work, we present a novel workflow for computing the phase diagrams of electrolyte systems described by classical force fields, using free-energy calculations from molecular dynamics simulations. We show that this approach is significantly more efficient than commonly employed direct coexistence (interfacial) simulation methods. In particular, we apply this “chemical potential route” to obtain the NaCl crystal–aqueous solution phase diagrams for both pure and hydrated crystals for two parameterizations of the Madrid scaled-charge force field. We show that the original model parameterization achieves state-of-the-art performance in predicting NaCl–water phase behavior at 1 bar within the temperature range of 250–350 K and predicts a stable hydrohalite (NaCl · 2H2O) crystal at temperatures below 250 K. Our approach enables potential future computational studies of hydrohalite nucleation.

From cationic to anionic Al12B and Al13 clusters. Aromatic characteristics for intermediate superatomic species

Al13- remains a prototypical superatomic cluster, featuring 40-cluster electrons (ce), fulfilling a closed shell electronic structure with spherical aromatic characteristics. Here, we evaluated intermediate counterparts, given by Al13+ (38-ce) and neutral Al13 (39-ce), which can be controlled by the use of different n- and p-type organic substrates, exhibiting a decreased spherical aromatic behavior. In addition, the boron-doped isoelectronic counterparts show similar characteristics. For both cationic and neutral clusters, a contrasting magnetic behavior is observed upon different orientations of the external field, in line with the decrease in spherical aromatic characteristics, resulting in a variation of the inherent magnetic anisotropy. Moreover, despite the decrease in spherical aromaticity, their characteristics remain, leading to these intermediate superatomic clusters being also depicted as stable building blocks toward the formation of molecular-based materials, offering prototypical examples of how superatomic clusters behave after interaction with substrates.

Dual-metal porphyrin–graphene hybrids as oxygen catalysts: Comparative DFT insights into O2 adsorption and activation

The efficient activation of molecular oxygen (O2) underpins electrochemical energy conversion; however, the design strategies for non-precious catalysts for the oxygen reduction reaction remain incomplete. Transition metal porphyrins supported on conductive substrates offer a versatile platform, but the mechanism by which different metal centers cooperate to control O2 activation is not well understood. In this work, we used density functional theory to explore heterometallic (Fe, Mn) porphyrin–graphene hybrids and reveal the decisive role of axial–core metal synergy. Across FeTPyP–Fe/Gr, FeTPyP–Mn/Gr, and MnTPyP–Fe/Gr, axial (bridging) sites consistently promote stronger O2 binding, greater charge transfer, and more pronounced weakening of the O–O bond than their core counterparts. Electronic-structure analysis showed that this effect arises from enhanced orbital overlap and π* occupation at the axial position, while Mn incorporation tunes the ligand field to further optimize O2 activation. The most effective configuration combines axial Fe binding with Mn-mediated electronic modulation, demonstrating that the complementary roles of distinct metals can be harnessed in a single catalytic architecture. These findings provide mechanistic insights into oxygen reduction and establish clear design principles for the engineering of earth-abundant porphyrin catalysts. More broadly, they highlight heterometallic coordination as a powerful strategy for tailoring molecular electrocatalysts for sustainable energy conversion.

Comparative study of conformational behavior of hydroxyl-terminated carbosilane dendrimers at water–toluene and water–air interfaces

In this study, we investigate how molecular density—governed by dendrimer generation and branching functionality—influences the conformational behavior and hydrogen bonding of OH-terminated carbosilane dendrimers in water, air, toluene, and at water–air and water–toluene interfaces by atomistic molecular dynamics simulations. We focus on the 4-3 series (G2–G4), featuring a tetrafunctional core and trifunctional branching, and compare it with the denser, more rigid 4-4G3 dendrimer of the third generation (tetrafunctional at both core and branching points). In hydrophobic environments, terminal OH groups form linear intramolecular aggregates; the 4-4G3 exhibits markedly reduced toluene uptake (10% vs 40% volume change for 4-3G4) and severely restricted intramolecular dynamics, with some OH groups remaining kinetically trapped near the core—a phenomenon requiring microsecond-scale simulations for proper characterization. In aqueous solution, 4-3 dendrimers expose OH groups at their periphery to form hydrogen bonds with water, whereas 4-4G3 retains a significant fraction of OH groups internally, forming intramolecular H-bonds instead. At interfaces, 4-3 dendrimers adopt flattened “umbrella” conformations to maximize interfacial H-bonding with water, swelling slightly into toluene to form biconvex shapes, while 4-4G3 remains nearly spherical due to steric constraints, forming over four times more intramolecular H-bonds and fewer with water than the more flexible 4-3G4. These findings establish molecular density as a key determinant of solvation, dynamics, and interfacial adaptability, providing a foundation for understanding structure–composition–property relationships in dendrimer monolayers under lateral confinement.

Revealing structure–property relationships and charge transfer dynamics in host–guest phosphorescent organic light-emitting diodes

Host materials are widely employed in organic light-emitting diodes (OLEDs) to achieve a high external quantum efficiency, initially presumed to function solely through molecular motion restriction. Recent experiments suggest that the host matrix may also facilitate energy transfer processes, yet theoretical understanding remains limited. Here, we employ non-adiabatic molecular dynamics to investigate excited state dynamics in a host–guest system comprising 2,7-dibromophenanthrene-9,10-dione (27PNDO) as the emitter and 6,11-dibromodibenzo-[f,h]quinoxaline (27QNX) as the host material. Our simulations reveal that 27QNX enables phosphorescence of 27PNDO at room temperature, a phenomenon that is absent in 27PNDO films due to inefficient singlet-to-triplet conversion. The binary system establishes two phosphorescence pathways: direct intersystem crossing in 27PNDO and energy transfer from the S1 state of 27QNX to a higher-lying triplet state of 27PNDO, followed by relaxation to T1. Molecular flexibility strongly influences exciton dynamics, with excessive conformational freedom in the 27PNDO dimer inhibiting intersystem crossing. Furthermore, molecular packing geometry proves crucial: antiparallel configuration facilitates S1 → T2 → T1 conversion, while parallel configuration induces molecular distortions that impede triplet state population. These findings emphasize the importance of both emitter selection and host material design in the development of efficient phosphorescence materials.

Thermal transport anomalies of electrolyte solutions in the water supercooled regime: Signatures of the liquid–liquid water phase transition

Water exhibits remarkable anomalies when supercooled, attributed to a hypothesized liquid–liquid phase transition (LLPT) between low-density and high-density liquid (HDL) phases. Using non-equilibrium molecular dynamics simulations, we explore thermal transport and coupled effects in supercooled NaCl and LiCl solutions (1–4 m, 200–300 K). At 1 m, thermal conductivity exhibits a pronounced minimum near 220 K, coinciding with maxima in isothermal compressibility and minima in the speed of sound, both of which are signatures of critical fluctuations. The anomalies progressively diminish with increasing salt concentration and vanish at 4 m, suggesting suppression of the LLPT. The Soret coefficient exhibits striking behavior, which is initially thermophobic at high temperatures (>280 K, solute migrates toward the cold side), becomes thermophilic upon cooling (solute migrates toward the hot side), and then reverts to thermophobic below 220 K. This behavior correlates with structural changes in the hydrogen-bond network of water. In particular, we find that the deep minima in the Soret coefficient, corresponding to the strongest thermophilic response in NaCl and LiCl, occur in thermodynamic states characterized by a low fraction of HDL-like structures, indicating a predominance of highly tetrahedrally ordered water environments. Furthermore, Seebeck coefficients exhibit sign reversals near 220–230 K, highlighting the thermoelectric sensitivity to structural transformations and temperature. These findings establish thermal transport as a sensitive probe of supercooled water, revealing that electrolyte solutions preserve the water’s anomalies deep into the supercooled regime.

High aspect ratio organic light-emitting diodes

Dynamics and transport of Bose–Einstein condensates in bent potentials

The dynamics of bosons in curved geometries have recently attracted significant interest in quantum many-body physics. Leveraging recent experimental advances in tailored trapping landscapes, we investigate the quantum transport of weakly interacting bosons in two-dimensional bent trapping potentials, showing that geometry alone can serve as a precise control knob for tunneling dynamics. Using time-adaptive many-body simulations, complemented by mean-field analysis and exact diagonalization, we analyze both static and dynamical properties of bosons confined in the bent potential. We reveal how bending an initially straight channel induces a transition from density localization to delocalization and drives the buildup of correlations in the ground state. In the dynamics, the bend acts as a tunable barrier that enables controllable tunneling: weak curvature allows coherent tunneling across the bend, while a stronger bend suppresses transport and enhances self-trapping. The tunneling rate can be precisely tuned by geometric parameters, establishing bent traps as versatile platforms for geometry-controlled quantum transport.

Glucagon-like peptide-1 receptor agonist in large vessel occlusion treated by reperfusion therapy—a phase 2 randomized trial

Abstract We aimed to determine the effect of semaglutide on patients with acute large vessel occlusion (LVO) receiving endovascular therapy (EVT). In this phase 2, investigator-initiated, multicenter, prospective, randomized, open-label, blinded endpoint trial conducted in China, we recruited patients with disabling LVO undergoing EVT. Patients were randomized to semaglutide therapy (0.5 mg subcutaneous semaglutide before and 1 week after EVT) or standard therapy. The primary outcome was defined as favorable neurological recovery (modified Rankin Scale 0–2 at 90 days). Between August 2023 and July 2024, 140 patients were randomized to semaglutide ( n  = 69) or standard therapy ( n  = 71). The primary outcome occurred in 39 (56.5%) in the semaglutide group and 39 (54.9%) in the standard therapy group (adjusted RR 1.05, 95% CI 0.95–1.15, p  = 0.37). We observed treatment effect modification by intravenous thrombolysis (IVT) on semaglutide therapy ( p interaction = 0.02); thus we performed the following exploratory analyses: The primary outcome occurred in 22 (64.7%) in the semaglutide group and 15 (44.1%) in the standard therapy group (adjusted RR 1.18, 95% CI 1.02–1.36) in the no-IVT stratum ( n  = 68). The primary outcome was similar between two groups in the IVT-stratum. No severe adverse event was attributed to semaglutide treatment. This phase 2 trial suggested semaglutide was safe in patients with LVO and was associated with an improved neurological outcome in patients not receiving IVT. These preliminary observations should be confirmed in a phase 3 randomized trial (ClinicalTrials.gov Identifier: NCT05920889).

Spectral decomposition of human BCL2 bonded to a PROTAC

In this study, we have decomposed the linear infrared spectra and two-dimensional infrared spectroscopy of a VHL-recruiting Proteolysis-targeting chimera (PROTAC) complex with BCL-2 to understand the spectral signatures of this complex. Our findings show that both VHL and BCL-2 units have distinct spectral signatures that contribute to the total spectra in different regions. Furthermore, we observed that the interaction between VHL and BCL-2 within the PROTAC complex leads to unique spectral features, indicating a strong synergistic effect. Through detailed analysis, specific bands were identified that correspond to the vibrational modes of the individual components, as well as their interactive modes within the complex. This study provides valuable insight into the molecular interactions within the PROTAC complex, offering a deeper understanding of its structure and function. These insights could be pivotal in designing more efficient PROTACs for targeted protein degradation in therapeutic applications.

Slower-growing species promote interspecific cooperation and coexistence under acid stress through cross-feeding

Transfer-learning enhanced adaptive sampling for accelerating ultrafast spectroscopy

Ultrafast transient absorption (TA) spectroscopy is a versatile tool for probing photoinduced dynamics in complex materials, but it often requires dense temporal sampling and extensive signal averaging, resulting in lengthy data acquisition times. Here, we present a data-driven sampling method, called Transfer-Learning Enhanced Adaptive Sampling (TEAS), which significantly accelerates TA measurements by reducing the number of required time points while preserving the full spectral and temporal information content of the original data. TEAS combines transfer learning with adaptive sampling to exploit cross-wavelength patterns, concentrating measurements on the most informative regions for greater efficiency and accuracy. The method does not rely on any specific mathematical or kinetic model, making it a flexible and general framework for accelerating measurements across a wide range of spectroscopic modalities. We demonstrate that this method can accurately reconstruct TA data using less than 1% of the total experimental measurements under varying signal-to-noise conditions, consistently outperforming traditional approaches that lack transfer learning or adaptive sampling. These results highlight the potential of TEAS as a broadly applicable, cost-effective solution for speeding up ultrafast spectroscopy and enabling real-time, data-driven experimentation.

Encapsulated faecal microbiota transfer in young women with anorexia nervosa: an open-label feasibility pilot trial

Shape anisotropy controls 2D melting pathway

The melting of two-dimensional systems is a fundamental challenge in condensed matter physics, where topological defects and thermal fluctuations play a key role. This work uses molecular dynamics simulations to investigate the melting of particles interacting via the Gay–Berne potential in the weak anisotropy regime (1.0 ≤ k ≤ 1.2). We demonstrate that the melting mechanism depends critically on the particle aspect ratio. For weak anisotropy (k < 1.15), the system follows a hybrid Bernard–Krauth scenario, featuring a continuous crystal-to-hexatic transition, followed by a first-order hexatic-to-isotropic liquid transition. At k ≥ 1.15, the system switches to the full Berezinskii–Kosterlitz–Thouless–Halperin–Nelson–Young scenario with two continuous Berezinskii–Kosterlitz–Thouless transitions. Introducing binary mixtures of particles with different anisotropies suppresses the first-order transition, stabilizing the continuous melting pathway. Therefore, weak shape anisotropy serves as a fundamental switching parameter governing the universal melting behavior of two-dimensional systems.

RHOA regulates mitochondria-ER contact sites through modulation of the VAPB/PTPIP51 tether