Magnetic and Thermodynamic Computations for Supramolecular Assemblies between a Cr(III) and Fe(III) Single-Ion Magnet and an Fe(II) Spin-Crossover Complex.

Experimental results on two supramolecular complexes in which a Cr or Fe d-orbital single-ion magnet center is embedded between a pair of Fe spin-crossover moieties make those two complexes interesting as possible candidates for use in quantum information technologies. We report detailed computational results for their structure and electronic properties and use the resulting data to parametrize a spin Hamiltonian that facilitates comparison with experimental results and their interpretation. Consistent with experimental results on decoherence in [Fe(ox)]@[FeL], we find it to be easy-plane type while the [Cr(ox)]@[FeL] system is easy-axis type.

Magnetoelectric Coupling in a MnNa-Organic Complex under Pulsed Magnetic Fields up to 73 T.

Research on the magnetoelectric (ME) effect (or spin-electric coupling) in molecule-based magnetic materials is a relatively nascent but promising topic. Molecule-based magnetic materials have diverse magnetic functionalities that can be coupled to electrical properties. Here we investigate a realization of ME coupling that is fundamental but not heavily studied─the coupling of magnetic spin level crossings to changes in electric polarization.

Caribbean medicinal plant Argemone mexicana L.: Metabolomic analysis and in vitro effect on the vaginal microbiota.

Ethnopharmacological Relevance: Medicinal plants are frequently used in Caribbean traditional medicine as low-cost, culturally relevant treatments for women's health concerns, such as gynecological infections. These plants are typically applied topically, potentially affecting both pathogenic bacteria (e.g.

Antibacterial Silver Nanoparticle Containing Polydopamine Hydrogels That Enhance Re-Epithelization.

A polydopamine polyelectrolyte hydrogel was developed by ionic crosslinking dextran sulfate with a copolymer of polyethyleneimine and polydopamine. Gelation was promoted by the slow hydrolysis of glucono-δ-lactone. Within this hydrogel, silver nanoparticles were generated in situ, ranging from 25 nm to 200 nm in size.

Engineering Clock Transitions in Molecular Lanthanide Complexes.

Molecular lanthanide (Ln) complexes are promising candidates for the development of next-generation quantum technologies. High-symmetry structures incorporating integer spin Ln ions can give rise to well-isolated crystal field quasi-doublet ground states, i.e.

Escherichia coli has an undiscovered ability to inhibit the growth of both Gram-negative and Gram-positive bacteria.

The ability for bacteria to form boundaries between neighboring colonies as the result of intra-species inhibition has been described for a limited number of species. Here, we report that intra-species inhibition is more common than previously recognized. We demonstrated that swimming colonies of four Escherichia coli strains and six other bacteria form inhibitory zones between colonies, which is not caused by nutrient depletion.

A sensor histidine kinase from a plant-endosymbiont bacterium restores the virulence of a mammalian intracellular pathogen.

Alphaproteobacteria include organisms living in close association with plants or animals. This interaction relies partly on orthologous two-component regulatory systems (TCS), with sensor and regulator proteins modulating the expression of conserved genes related to symbiosis/virulence. We assessed the ability of the exoS gene, encoding a sensor protein from the plant endosymbiont Sinorhizobium meliloti to substitute its orthologous bvrS in the related animal/human pathogen Brucella abortus.

All-electron APW+lo calculation of magnetic molecules with the SIRIUS domain-specific package.

We report APW+lo (augmented plane wave plus local orbital) density functional theory (DFT) calculations of large molecular systems using the domain specific SIRIUS multi-functional DFT package. The APW and FLAPW (full potential linearized APW) task and data parallelism options and the advanced eigen-system solver provided by SIRIUS can be exploited for performance gains in ground state Kohn-Sham calculations on large systems. This approach is distinct from our prior use of SIRIUS as a library backend to another APW+lo or FLAPW code.

Search for Toroidal Ground State and Magnetoelectric Effects in Molecular Spin Triangles with Antiferromagnetic Exchange.

Using first-principles methods and spin models, we investigate the magnetic properties of transition-metal trimers Cr and Cu. We calculate exchange coupling constants and zero-field splitting parameters using density functional theory and, with these parameters, determine the ground spin state as well as thermodynamic properties via spin models. Results for Cr indicate uniaxial magnetic anisotropy with a magnetic easy axis aligned along the 3-fold rotational symmetry axis and a mostly isotropic exchange interaction.

Near-Room-Temperature Magnetoelectric Coupling via Spin Crossover in an Iron(II) Complex.

Magnetoelectric coupling is achieved near room temperature in a spin crossover Fe molecule-based compound, [Fe(1bpp) ](BF ) . Large atomic displacements resulting from Jahn-Teller distortions induce a change in the molecule dipole moment when switching between high-spin and low-spin states leading to a step-wise change in the electric polarization and dielectric constant. For temperatures in the region of bistability, the changes in magnetic and electrical properties are induced with a remarkably low magnetic field of 3 T.

Dipole Switching by Intramolecular Electron Transfer in Single-Molecule Magnetic Complex [MnO(OCR)(HO)].

We study intramolecular electron transfer in the single-molecule magnetic complex [MnO(OCR) (HO)] for R = -H, -CH, -CHCl, -CH, and -CHF ligands as a mechanism for switching of the molecular dipole moment. Energetics is obtained using the density functional theory (DFT) with onsite Coulomb energy correction (DFT + ). Lattice distortions are found to be critical for localizing an extra electron on one of the easy sites on the outer ring in which localized states can be stabilized.

First-principles calculation of gate-tunable ferromagnetism in magic-angle twisted bilayer graphene under pressure.

Magic-angle twisted bilayer graphene (MATBG) is notable as a highly tunable platform for investigating strongly correlated phenomena such as unconventional superconductivity and quantum spin liquids, due to easy control of doping level through gating and sensitive dependence of the magic angle on hydrostatic pressure. Experimental observations of correlated insulating states, unconventional superconductivity and ferromagnetism in MATBG indicate that this system exhibits rich exotic phases. In this work, using density functional theory calculations in conjunction with the effective screening medium method, we find the MATBG under pressure at a twisting angle of 2.

Low-Depth Unitary Coupled Cluster Theory for Quantum Computation.

The unitary coupled cluster (UCC) approximation is one of the more promising wave function ansätzes for electronic structure calculations on quantum computers via the variational quantum eigensolver algorithm. However, for large systems with many orbitals, the required number of UCC factors still leads to very deep quantum circuits, which can be challenging to implement. Based on the observation that most UCC amplitudes are small for both weakly correlated and strongly correlated molecules, we devise an algorithm that employs a Taylor expansion in the small amplitudes, trading off circuit depth for extra measurements.

Using Hyperoptimized Tensor Networks and First-Principles Electronic Structure to Simulate the Experimental Properties of the Giant {Mn} Torus.

The single-molecule magnet {Mn} is a challenge to theory because of its high nuclearity. We directly compute two experimentally accessible observables, the field-dependent magnetization up to 75 T and the temperature-dependent heat capacity, using parameter-free theory. In particular, we use first-principles calculations to derive short- and long-range exchange interactions and compute the exact partition function of the resulting classical Potts and Ising spin models for all 84 Mn = 2 spins to obtain observables.

Flexibility of the factorized form of the unitary coupled cluster Ansatz.

The factorized form of the unitary coupled cluster Ansatz is a popular state preparation Ansatz for electronic structure calculations of molecules on quantum computers. It is often viewed as an approximation (based on the Trotter product formula) for the conventional unitary coupled cluster operator. In this work, we show that the factorized form is quite flexible, allowing one to range from a conventional configuration interaction, to conventional unitary coupled cluster, to efficient approximations that lie in between these two.

Ligand Optimization of Exchange Interaction in Co(II) Dimer Single Molecule Magnet by Machine Learning.

Designing single-molecule magnets (SMMs) for potential applications in quantum computing and high-density data storage requires tuning their magnetic properties, especially the strength of the magnetic interaction. These properties can be characterized by first-principles calculations based on density functional theory (DFT). In this work, we study the experimentally synthesized Co(II) dimer (Co(CNH)(μ-PO(CHCH))) SMM with the goal to control the exchange energy, Δ, between the Co atoms through tuning of the capping ligands.

Solvothermal Synthesis of [Cr S (en) Cl ]Cl ⋅ 2H O with Magnetically Frustrated [Cr S ] Double-Cubes.

A novel transition metal chalcohalide [Cr S (en) Cl ]Cl  ⋅ 2H O, with [Cr S ] dicubane cationic clusters, has been synthesized by a low temperature solvothermal method, using dimethyl sulfoxide (DMSO) and ethylenediamine (en) solvents. Ethylenediamine ligand exhibits bi- and monodentate coordination modes; in the latter case ethylenediamine coordinates to Cr atoms of adjacent clusters, giving rise to a 2D polymeric structure. Although magnetic susceptibility shows no magnetic ordering down to 1.

Asymmetric Design of Spin-Crossover Complexes to Increase the Volatility for Surface Deposition.

A mononuclear complex [Fe(Buqsal)] has been obtained by a reaction between an Fe(II) precursor salt and a tridentate ligand 2,4-di(-butyl)-6-((quinoline-8-ylimino)methyl)phenol (BuqsalH) in the presence of triethylamine. The complex exhibits a hysteretic spin transition at 117 K upon cooling and 129 K upon warming, as well as light-induced excited spin-state trapping at lower temperatures. Although the strongly cooperative spin transition suggests substantial intermolecular interactions, the complex is readily sublimable, as evidenced by the growth of its single crystals by sublimation at 573 → 373 K and ∼10 mbar.

Analysis of two-level systems and mechanical loss in amorphous ZrO-doped TaO by non-cage-breaking and cage-breaking transitions.

The energy landscape of ZrO-doped amorphous TaO is explored in this work. With models corresponding to experimental concentrations of 50% Zr and 50% Ta cations, we search for, gather, and analyze two-level systems (TLSs) from molecular dynamic simulations. The mechanical loss function is calculated for each TLS individually.

Tailoring electrocatalytic activity of in situ crafted perovskite oxide nanocrystals via size and dopant control.

Perovskite oxides (ABO) have been widely recognized as a class of promising noble-metal-free electrocatalysts due to their unique compositional flexibility and structural stability. Surprisingly, investigation into their size-dependent electrocatalytic properties, in particular barium titanate (BaTiO), has been comparatively few and limited in scope. Herein, we report the scrutiny of size- and dopant-dependent oxygen reduction reaction (ORR) activities of an array of judiciously designed pristine BaTiO and doped BaTiO (i.

Quantum-Inspired Algorithm for the Factorized Form of Unitary Coupled Cluster Theory.

The factorized form of unitary coupled cluster theory (UCC) is a promising wave-function ansatz for the variational quantum eigensolver algorithm. Here, we present a quantum-inspired classical algorithm for UCC based on an exact operator identity for the individual UCC factors. We implement this algorithm for calculations of the H linear chain and the HO molecule with single and double ζ basis sets to provide insights into UCC as a wave-function ansatz.

Giant Magnetoelectric Coupling and Magnetic-Field-Induced Permanent Switching in a Spin Crossover Mn(III) Complex.

We investigate giant magnetoelectric coupling at a Mn spin crossover in [MnL]BPh (L = (3,5-diBr-sal)323) with a field-induced permanent switching of the structural, electric, and magnetic properties. An applied magnetic field induces a first-order phase transition from a high spin/low spin (HS-LS) ordered phase to a HS-only phase at 87.5 K that remains after the field is removed.

Application of Quantum Computing to Biochemical Systems: A Look to the Future.

Chemistry is considered as one of the more promising applications to science of near-term quantum computing. Recent work in transitioning classical algorithms to a quantum computer has led to great strides in improving quantum algorithms and illustrating their quantum advantage. Because of the limitations of near-term quantum computers, the most effective strategies split the work over classical and quantum computers.

Gaultheria longibracteolata, an alternative source of wintergreen oil.

Gaultheria longibracteolata (Ericaceae) has been traditionally used by different linguistic groups in Yunnan Province, China, but it has not been well studied. Through our ethnobotanical study in Lüchun County of Yunnan, we found that this species has multiple traditional uses including food, medicine, and worship. The essential oils from the root, stem, and leaf were investigated by both GC-MS and anti-bacterial assays.

Assessment of the efficacy of α-lipoic acid in treatment of diabetes mellitus patients with erectile dysfunction: A protocol for systematic review and meta-analysis.

Background: Diabetes mellitus with erectile dysfunction (DMED) is one of the most common causes of disability in diabetic population, and its pathogenesis is related to a variety of factors. Because its pathogenesis is complex and the existing treatment methods have limitations, DMED is difficult to treat in clinical. Recently, some studies have shown that α-lipoic acid (ALA) is associated with DMED, but there is no systematic review and meta-analysis on the relationship between ALA and DMED.