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Oxygen vacancy (VO) has been recognized to possess an effect to promote the charge separation and transfer (CST) in various n‐type semiconductor based photoelectrodes. But how external stimulus will change this VO effect has not been investigated. In this work, external polarization is applied to investigate the effect of VO on the CST process of a typical ferroelectric BiFeO3 photoelectrode. It is found that negative poling treatment can significantly boost VO effect, while positive poling treatment will deteriorate the CST capability in BiFeO3 photoelectrodes. This poling history determined VO effect is rooted in the VO induced defect dipoles, wherein their alignment produces a depolarization electric field to modulate the CST driving force. This finding highlights the significance of poling history in functionalizing the VO in a photoelectrode. [ABSTRACT FROM AUTHOR]

Surfaces with photoswitchable wettability are of great interest for various applications such as smart coatings or liquid condensation. The photochromic ring opening reaction of spiropyran (SP) to merocyanine (MC) implies a high dipole moment change, making it interesting for photo‐controlled wetting properties. In addition to the material chemistry, surface wettability is influenced by the surface topography. Porous SP copolymers with various micro‐/nanostructures, that is, different submicron roughness, are fabricated via polymerization‐induced phase separation. The influence of the surface topography on the photoswitchable wetting properties is studied. Surfaces with arithmetic mean roughness (Sa) below 150 nm exhibited a maximum static contact angle (SCA) photoswitch up to 16° from 124 ± 6° to 108 ± 4° upon UV exposure. While superhydrophobic surfaces with higher Sa (157 – 608 nm) showed an insignificant SCA switch. The latter surfaces have a SCA above 150° and low CA hysteresis indicating small and insufficient contact with SP/MC surface asperities for the switch. With the optimized surfaces, photo‐controlled water condensation is studied on microscale and showed that the condensate droplets merged faster, and formed larger droplets pinned to the original contact lines on surfaces switched to the less hydrophobic state. [ABSTRACT FROM AUTHOR]

Effects of the number of monomers (N) on the two-photon absorption (TPA) properties of π-stacked multimer models consisting of phenalenyl radicals were investigated theoretically. We conducted spectral simulations for the π-stacked N-mer models (N = 2, 4, and 6) with different stacking distances (d1) and their alternation patterns (d2/d1). Excitation energies and transition dipole moments were calculated at the extended multi-configurational quasi-degenerate second-order perturbation theory (XMC-QDPT2) level based on the complete active space self-consistent field (CASSCF) wavefunctions with the active space orbitals constructed from the singly occupied molecular orbitals (SOMOs) of monomers. The TPA cross-section value per dimer unit at the first peak, originating from the electronic transition along the stacking direction, was predicted to increase significantly as the d2/d1 approaches one, as the d1 decreases, and as the N increases from 2 to 6. These tendencies are similar to the calculation results for the static hyperpolarizabilities. [ABSTRACT FROM AUTHOR]

The effect of solvents on kinetic parameters of anionic polymerization is complex and a comprehensive theoretical study has been rare. In this work, four solvent polarity descriptors (i.e., polarizability, dipole moment, nucleophilic index, electrophilic index) are correlated with solvent parameters (Ea, A, ΔH‡, and ΔS‡) by multiple linear regression using the Catalan linear free‐energy relationship (LFER) equation for the anionic polymerization of styrene. The results show that Ea, ΔH‡, and ΔS‡ have a low correlation with dipole moment, whereas A is strongly correlated with dipole moment. Given the fact that the larger A the larger effective collision frequency Z, it is hypothesized that in polar solvents, the polymer chains are more extended, enabling more effective collisions between monomers and active anionic species during polymerization. In contrast, in nonpolar solvents, the polymer chains collapse, making it more difficult for the monomer to be inserted into the ion pairs. Subsequently, n‐pentane and tetrahydrofuran are chosen as representatives to confirm this conjecture by molecular simulations. Lastly, Ea, A and kp are predicted for 173 solvents using well‐established descriptive relationships. [ABSTRACT FROM AUTHOR]

Interfacial dipole moment engineering in self-recoverable mechanoluminescent platform explores a simple and innovative method to modulate the internal triboelectric field in a self-recoverable mechanoluminescent platform. This study elucidates a direct relationship between dipole moment strength and mechanoluminescence brightness by modifying the surface of ZnS@metal oxide phosphor with functionalized benzoic acid derivatives. Our platform can be effectively applied to practical applications, including anti-counterfeiting systems. [Display omitted] • Interfacial modification enhances triboelectric field, boosting ML brightness by 27.4 %. • Aminobenzoic acid (ABA) surface treatment achieves significant ML performance increase. • Developed ML platform suitable for anti-counterfeiting and wearable display applications. • Surface dipole moment engineering offers a versatile approach to optimize ML properties for various applications. Harnessing the potential of mechanoluminescence (ML) for practical applications necessitates innovations that maximize brightness while simplifying the platform. Our study introduces a pioneering interfacial modification technique that enhances the internal triboelectric field in a self-recoverable ML platform based on zinc sulfide@metal oxide phosphor and a polydimethylsiloxane matrix. By chemically functionalizing the surface of metal oxide shells with benzoic acid derivatives, we modulate surface charge density thereby intensifying the triboelectric field within the ML platform. Utilizing a range of derivatives with varying dipole moments establishes a direct relationship between dipole moment strength and triboelectric enhancement. Notably, introducing aminobenzoic acid (ABA) onto the surface of the aluminum oxide (AlO x) shell results in a significant increase in ML brightness. Our strategy to easily adjust the ML brightness has been applied to anti-counterfeiting applications. Our study not only reveals the correlation between surface triboelectric fields and ML performance but also provides the possibility for practical use of self-recoverable ML platforms in various application fields, including smart textiles, health monitoring systems, and wearable displays. [ABSTRACT FROM AUTHOR]

The seventh blind test of crystal structure prediction (CSP) methods substantially increased the level of complexity of the target compounds relative to the previous tests organized by the Cambridge Crystallographic Data Centre. In this work, the performance of density‐functional methods is assessed using numerical atomic orbitals and the exchange‐hole dipole moment dispersion correction (XDM) for the energy‐ranking phase of the seventh blind test. Overall, excellent performance was seen for the two rigid molecules (XXVII, XXVIII) and for the organic salt (XXXIII). However, for the agrochemical (XXXI) and pharmaceutical (XXXII) targets, the experimental polymorphs were ranked fairly high in energy amongst the provided candidate structures and inclusion of thermal free‐energy corrections from the lattice vibrations was found to be essential for compound XXXI. Based on these results, it is proposed that the importance of vibrational free‐energy corrections increases with the number of rotatable bonds. [ABSTRACT FROM AUTHOR]

The presented work proposes that the self-assembly of amphiphilic compounds in Xiaoqu Baijiu occurs at the distillation and condensation stage of Chinese Baijiu production for the first time. Such phenomena have similitude with the self-assembly nano-particles conducted by evaporation and condensation approaches. Hydrogen-bonding interactions prompting the formation of molecular clusters in the system. Herein, we characterized the variation of dipole moment, hydrogen bond strength, and cluster morphology in Xiaoqu Baijiu, based on electrochemical impedance spectroscopy, Raman spectroscopy, atomic force microscopy, and molecular dynamics simulation. The effects of major aroma substances on the self-assembly of Xiaoqu Baijiu were fully investigated, it turns out ethyl lactate had the strongest effect on resulting in self-assembled clusters. [ABSTRACT FROM AUTHOR]

Para‐phenylene‐bridged pyridinium (acceptor)–dicyanomethanide (donor)‐based zwitterions were computationally investigated and are reported here. Reichardt's metamer was found to be twisted and Brooker's metamer in near‐planar conformation. Natural bond orbital (NBO) analysis showed that mesomeric resonance is helping Brooker's metamer but found to be not helpful for Reichardt's metamer. To assess the impacts of metamerism and aromatic bridges, fundamental molecular properties like dipole moments (μ), polarizabilities (α), hyperpolarizabilities (β), and adiabatic absorptions of these two molecules were analyzed and then directly compared with their counterpart zwitterions without any bridges (previously reported). Results of impact of metamerism: Reichardt's metamer showed around three times enhanced hyperpolarizabilities (ωB97xD: β = 1577.1 × 10−30 esu) than the Brooker's metamer (ωB97xD: β = 532.5 × 10−30 esu). Impacts of p‐phenylene bridges: Compared to their respective D–A directly connected zwitterions reported previously (in ωB97xD methodology, Reichardt's: β = 257.2 × 10−30 esu and Brooker's: β = 67.2 × 10−30 esu), respective p‐phenylene‐bridged zwitterions showed five to eight times enhanced hyperpolarizabilities. This report highlights the better efficiencies of Reichardt's metamer over Brooker's metamer and aromatically bridged over the directly connected zwitterions. Current findings may be helpful in the designing of efficient functional molecular chromophores, and aromatic bridge combined with zwitterions can be solutions to nonlinear transparency trade‐off problem. [ABSTRACT FROM AUTHOR]

The complex dielectric permittivity of Polyvinylpyrrolidone (PVP K-30) [C6H9ON]n in four different alcohols (methanol, ethanol, propanol, and butanol) with no. of carbon atoms ranging from one to four has been determined in the frequency range of 10 MHz to 50 GHz over the temperature range of 278.15–298.15 K at various concentrations of PVP (C) using time-domain reflectometry technique. The dielectric permittivity spectra were described using the Cole-Davidson model. Two modes of relaxation processes were observed, namely low-frequency (secondary) and high-frequency (primary) relaxation. The low-frequency relaxation is due to the interaction between solute–solvent molecules, whereas the reorientation of solvent molecules is responsible for the high-frequency dispersion of relaxation. By using the Harviliak-Negami equation, the frequency-dependent complex dielectric permittivity has been studied. Dielectric parameters such as static dielectric constant (εj), relaxation time (τj), dipole moment (û), Kirkwood correlation factor (g1), number of solvent molecules irrotationally bound to solute molecules (Zib), and effective volume of rotation (Veff) were determined. In addition to this, thermodynamic properties such as the free energy of activation (ΔFj), enthalpy of activation (ΔHj), and entropy of activation (ΔSj) were also calculated. It was observed that the low-frequency static dielectric constant (εl) increases with the PVP concentration in all cases except in methanol. εl values strongly depend on the temperature, and they increase as the temperature of the system decreases, whereas the high-frequency dielectric constant (εh) increases towards higher concentrations of solute molecule as well as towards lower temperatures. [ABSTRACT FROM AUTHOR]

Utilizing carbon coated ferroelectric materials to introduce polarization‐induced electric field (PIEF) stimulates research of electric field‐assisted catalysts for various reactions. However, effect of PIEF on carbon coating mechanism has not been studied. Herein, tourmaline nanoparticles (TNPs) with spontaneous dipole moments were applied as the PIEF supplier and sucrose was utilized as the carbon precursor to synthesize carbon coated TNPs (TNP@SC) to uncover the influence of PIEF on the carbon coating and catalytic activity of Pd toward formic acid decomposition (FAD). PIEF enhanced the adsorption capacity of TNPs for the caramelized intermediate species and increased H+ concentration by facilitating water ionization. Polymerization of adsorbed caramelized intermediate species on TNPs was accelerated. Uniformly coated carbon layer with more defects, larger specific surface area, and higher porosity was coated on TNP. Such surface properties of the carbon layer were beneficial for strongly anchoring ultrafine Pd nanoparticles. Owing to the specific properties of carbon layer and existence of PIEF, Pd/TNP@SC exhibited higher FAD activity than the catalysts absent of PIEF. Stronger PIEF leaded to higher initial turnover frequency. This study provides guidance to supply electric field for catalysis. [ABSTRACT FROM AUTHOR]

This study systematically examines the effects of diphenylphosphinic acid (DPPA) and sarcosine (SAR) intercalation into magnesium aluminum lanthanum hydrotalcite (LDHs) on its structure and thermal stability. Using charge distribution, structural optimization, energy calculations, XRD, FTIR, TEM, and thermal stability tests, the study reveals that DPPA anions, with higher negative charge density, increase the interlayer spacing to 6.08 Å and exhibit a binding energy of −0.7624 eV. SAR anions, with a thinner interlayer spacing of 4.11 Å and a binding energy of −1.603 eV, create a more stable structure. SAR's higher dipole moment (2.827 a.u.) compared to DPPA (2.077 a.u.) enhances electrostatic interactions. Thermal stability tests show SAR‐LDHs and DPPA‐LDHs extend PVC's stability to 53.67 and 56.67 min, respectively. DPPA anions provide superior stability at high temperatures, while SAR anions excel in moderate temperatures. This study offers insights for designing thermally stable composite materials. [ABSTRACT FROM AUTHOR]

Aqueous zinc‐sulfur batteries (Zn−S) are promising alternatives to conventional lithium‐ion technology due to their high energy density, low cost, and enhanced safety. However, challenges such as slow redox kinetics of sulfur cathode conversion and inadequate anode stability persist. This study demonstrates that by tuning the electrolyte structure with the introduction of propylene glycol methyl ether (PM) as a co‐solvent and ZnI2 as an electrolyte additive, and significant improvements at both electrodes could be achieved. Experimental and theoretical calculations reveal that the larger polar −OH and C−O−C electron‐donating groups in the PM molecule can donate electrons for the redox reaction of I−/I3−. Its role as a redox mediator improves the reversibility of the sulfur cathodic transformation. Additionally, the dipole moment induced by the hydroxyl groups in PM enhances electron transfer from the zinc anode to the electrolyte and promote the decomposition of anions (OTF−), improving the interfacial stability of the zinc anode. The synergistic effect of PM and the I−/I3− redox mediator pair enables the zinc‐sulfur battery to deliver an impressive capacity of 1456 mAh g−1 and a high energy density of 471.8 Wh kg−1 at a current density of 0.2 A g−1. [ABSTRACT FROM AUTHOR]

Mn(II)‐based halides have recently garnered significant interest as emerging luminescence materials for diverse photonic applications. Generally, Mn(II) hybrids with tetrahedral coordination show green emission, however, ones with octahedral coordination give red emission. Herein, we design the synthesis of tetrahedral Mn(II) pseudohalide hybrids, (RPh3P)2MnBrxNCS4−x (R=phenyl, pentyl or methyl; Ph3P=triphenylphosphine; x=1–3), achieved by gradually substituting bromides with pseudohalides (NCS−). Compared to the green‐emitting A2MnBr4 (512 nm), the mixed hybrids exhibit significantly distorted [MnBrxNCS4−X] tetrahedra with high dipole moment, thus leading to the distinct Stokes shift energies and noticeable red shift emission in the range of 549–613 nm. Furthermore, the photoluminescence quantum yield (PLQY) of these hybrids correlates strongly with the pair correlation function of Mn(II) ions, specifically the Mn⋅⋅⋅Mn distance. These findings highlight the critical role of dipole moments in determining the emission properties and expand the luminescent family of Mn(II) pseudohalide hybrids. [ABSTRACT FROM AUTHOR]

This study is a theoretical approach to elucidate the structural, energetic, and spectroscopic properties of already synthesized derivatives of 2H‐iminopyran (4a–4j) by us. Our findings reveal that molecular symmetry, dipole moment, polarizability, and global reactivity descriptors significantly influence the behavior of these compounds within the context of multicomponent reactions. Molecular electrostatic potential surfaces (MEPS) provide valuable insights into potential reactive sites and intermolecular interactions, crucial for understanding the efficiency and selectivity of multicomponent processes that are found to be in accordance with the experimental results. Thermodynamic analysis offers further clarification on the driving forces behind the formation of these compounds. These insights can be leveraged to optimize reaction conditions, design novel multicomponent strategies, and predict the outcome of future synthetic endeavors in this area. [ABSTRACT FROM AUTHOR]

The distribution of biomolecules within cells changes upon aging and diseases. To quantitatively determine the spatial distribution of components inside cells, we built the user-friendly open-source 3D-cell-image analysis platform Cell Detection and Analysis of Intensity Lounge (CellDetail). The algorithm within CellDetail is based on the concept of the dipole moment. CellDetail provides quantitative values for the distribution of the polarity proteins Cdc42 and Tubulin in young and aged hematopoietic stem cells (HSCs). Septin proteins form networks within cells that are critical for cell compartmentalization. We uncover a reduced level of organization of the Septin network within aged HSCs and within senescent human fibroblasts. Changes in the Septin network structure might therefore be a common feature of aging. The level of organization of the network of Septin proteins in aged HSCs can be restored to a youthful level by pharmacological attenuation of the activity of the small RhoGTPase Cdc42. Tools to determine the spatial distribution of components and their networks inside cells are not well developed. Here, authors provide the open-source 3D-cell-image analysis platform Cell Detection and Analysis of Intensity Lounge (CellDetail) for quantitative distribution analyses. [ABSTRACT FROM AUTHOR]

Through first-principles calculations based on density functional theory, we investigate the crystal and electronic structures of twisted bilayer BaTiO3. Our findings reveal that large stacking fault energy leads to a chiral in-plane vortex pattern that was recently observed in experiments. We also found nonzero out-of-plane local dipole moments, indicating that the strong interlayer interaction might offer a promising strategy to stabilize ferroelectric order in the two-dimensional limit. The vortex pattern in the twisted BaTiO3 bilayer supports localized electronic states with quasi-flat bands, associated with the interlayer hybridization of oxygen pz orbitals. We found that the associated bandwidth reaches a minimum at ~19° twisting, configuring the largest magic angle in moiré systems reported so far. Further, the moiré vortex pattern bears a notable resemblance to two interpenetrating Lieb lattices and the corresponding tight-binding model provides a comprehensive description of the evolution the moiré bands with twist angle and reveals the topological nature. [ABSTRACT FROM AUTHOR]

Perovskite/perovskite/silicon triple‐junction tandem solar cells (TSCs) hold promise for high power conversion efficiencies (PCE). However, the efficiency is still relatively low due to the non‐radiative recombination losses in wide‐bandgap top cells. These losses, attributed to the interface defect states and energy level mismatches, present considerable challenges to realizing high‐performance and stable TSCs. Here, the molecular synergistic effect (MSE) is exploited to passivate interface in 1.95 eV top cells. Piperazine‐1‐carboxamide hydrochloride (PCACl) is combined, which possesses strong dipole moments and passivating functional groups that can bind with two neighboring uncoordinated lead ions and form hydrogen bonds with halide atoms at perovskite surface, with 1,3‐propane‐diammonium iodide, which can reduce interface recombination through field‐effect passivation. The MSE enabled by PCACl and PDAI2 facilitates excellent energy level alignment and reduces non‐radiative recombination losses and light‐induced phase segregation. Finally, the target perovskite/perovskite/silicon triple‐junction TSC obtains an open‐circuit voltage of 3.07 V and a champion PCE of 25.2% (for a 1.035 cm2 aperture area). [ABSTRACT FROM AUTHOR]

Wrinkles are used in manufacturing stretchable electronics, soft materials, smart displays, and microstructures. The emerging 2D materials enable the investigation of the intertwined piezoelectric and flexoelectric coupling effect in wrinkled structures and their energy, sensing, and other applications. However, current studies of the electromechanical coupling effect often consider it one effect or even overlook one of the two effects. This oversimplification leads to inaccuracies in the analysis. Here, a theoretical model is proposed to separate the piezoelectric and flexoelectric coefficients by fitting polarization formulas with discrete polarization values calculated using density functional theory. Wrinkled ZnO monolayers are built to mimic the realistic situation, where six nonzero coefficients are successfully isolated, revealing that the coupling of piezo/flexoelectricity and the contribution of piezoelectric and flexoelectric polarizations to the total polarization vary in different directions. Combined with the dipole moment analysis, the relationship between the polarization, piezoelectric coefficient, flexoelectric coefficient, and wrinkle amplitude is established. This study demonstrates that increasing the wrinkle amplitude significantly decreases the energy gap of 560 meV. The separation and quantification of piezoelectric and flexoelectric effects advance the understanding of wrinkles' mechanical and electromechanical properties and lay the foundation for their future applications. [ABSTRACT FROM AUTHOR]

The ternary copolymerization strategy has emerged as a promising strategy for developing high‐efficiency donor polymers in polymer solar cells (PSCs). Terpolymers based on the star polymer PM6 have already realized good photovoltaic performance. However, challenges such as the intricate synthesis of fluorine‐substituted benzodithiophene (F‐BDT) unit of PM6 and entropy increase induced by backbone disorder have hindered the construction of high‐performance donor terpolymers. In this work, these challenges are addressed by opting for the cost‐effective chlorinated‐substituted benzodithiophene unit (Cl‐BDT) as an alternative to F‐BDT and incorporating the large dipole moment and electron‐deficient TPD group as the third component into the high‐performance donor polymer of PM7. As expected, this approach effectively suppresses terpolymer backbone disorder while enhancing crystallinity, thereby optimizing morphology and improving charge generation and transport. Remarkably, the PM7‐TPD‐10‐based device with 10% TPD replacement achieves a champion power conversion efficiency (PCE) of 18.26%. After introducing PM7‐TPD‐10 as the third component into D18:L8‐BO blend, a dual mechanism for improving the efficiency to 19.40% is realized. This work demonstrates that the high dipole moiety as the third component to construct terpolymers is an important strategy to suppress the backbone disorder and increase the crystallinity, facilitating the optimization of morphology and device performance. [ABSTRACT FROM AUTHOR]

Results are presented for the measurement of large-scale anisotropies in the arrival directions of ultra–high-energy cosmic rays detected at the Pierre Auger Observatory during 19 yr of operation, prior to AugerPrime, the upgrade of the observatory. The 3D dipole amplitude and direction are reconstructed above 4 EeV in four energy bins. Besides the established dipolar anisotropy in R.A. above 8 EeV, the Fourier amplitude of the 8–16 EeV energy bin is now also above the 5 σ discovery level. No time variation of the dipole moment above 8 EeV is found, setting an upper limit to the rate of change of such variations of 0.3% yr−1 at the 95% confidence level. Additionally, the results for the angular power spectrum are shown, demonstrating no other statistically significant multipoles. The results for the equatorial dipole component down to 0.03 EeV are presented, using for the first time a data set obtained with a trigger that has been optimized for lower energies. Finally, model predictions are discussed and compared with observations, based on two source emission scenarios obtained in the combined fit of spectrum and composition above 0.6 EeV. [ABSTRACT FROM AUTHOR]

Using GPU-accelerated state-vector emulation, we propose to embed a quantum computing ansatz into density-functional theory via density-based basis-set corrections to obtain quantitative quantum-chemistry results on molecules that would otherwise require brute-force quantum calculations using hundreds of logical qubits. Indeed, accessing a quantitative description of chemical systems while minimizing quantum resources is an essential challenge given the limited qubit capabilities of current quantum processors. We provide a shortcut towards chemically accurate quantum computations by approaching the complete-basis-set limit through coupling the density-based basis-set corrections approach, applied to any given variational ansatz, to an on-the-fly crafting of basis sets specifically adapted to a given system and user-defined qubit budget. The resulting approach self-consistently accelerates the basis-set convergence, improving electronic densities, ground-state energies, and first-order properties (e.g. dipole moments), but can also serve as a classical, a posteriori, energy correction to quantum hardware calculations with expected applications in drug design and materials science. Quantum computing offers a promising approach to solving electronic-structure problems, but a quantitative description of chemical systems while minimizing computing resources is an essential challenge. Here, the authors provide a shortcut towards chemically accurate quantum computations by approaching the complete-basis-set limit through coupling the density-based basis-set corrections approach, applied to any given variational ansatz, to an on-the-fly crafting of basis sets specifically adapted to a given system and user-defined qubit budget. [ABSTRACT FROM AUTHOR]

We study experimentally and theoretically the influence of size effects and structural factors on the dielectric and ferroelectric properties of the dense ferroelectric composites. The composites have the form of the tape-casted films with 28 vol% of nanosized or submicron BaTiO 3 particles dispersed in the polyvinyl butyral. We measured and analyzed the temperature dependences of the capacitance and dielectric losses in the temperature range (−200 – +200)oC and frequency range (102–105) Hz. The nonmonotonic temperature dependences of dielectric permittivity of the studied composite films have a wide plateau-like maxima located between 80oС and 160oС, in contrast to the relatively sharp maximum near the Curie temperature (∼124oC) observed in the fine-grained and coarse-grained ceramics, sintered from the same nanosized or submicron BaTiO 3 particles at 1250oC. The shift of the dielectric permittivity and losses maxima (in more than 40oC) and their strong frequency dispersion do not agree with the behavior expected for the systems with a weak interaction between ferroelectric particles and a polymeric matrix. In contrast, we reveal the relaxor-like behavior of the composite dielectric response. To explain the observed results, we propose the analytical model, which considers the strong dipole-dipole cross-interaction of the BaTiO 3 particles in the dense nanocomposite. The analytical model is corroborated by the structural studies of the BaTiO 3 nanosized and submicron particles by X-ray phase analysis and static 137Ba NMR spectra, as well as by the finite element modelling of the composite polar properties, which confirms the strong cross-interactions between the dipole moments of single-domain nanoparticles and/or between the domain walls of different submicron polydomain particles. The obtained results may be useful for development of cheap and flexible lead-free dense ferroelectric nanocomposites with relaxor-like behavior of the dielectric response, which are promising for non-volatile memory and energy-saving elements, modulators, electrical converters and piezoresistive elements. [ABSTRACT FROM AUTHOR]

Changes in the work function provide a fingerprint to characterize analyte binding in charge transfer-based sensor devices. Hence, a rational sensor design requires a fundamental understanding of the microscopic factors controlling the modification of the work function. In the current investigation, we address the mechanisms behind the work function change (WFC) for the adsorption of four common volatile organic compounds (toluene, ethanol, 2-Furfurylthiol, and guaiacol) on different nitrogen-doped graphene-based 2D materials using density functional theory. We show that competition between the surface dipole moment change induced by spatial charge redistribution, the one induced by the pure adsorbate, and the one caused by the surface deformation can quantitatively predict the work function change. Furthermore, we also show this competition can explain the non-growing work function change behavior in the increasing concentrations of nitrogen-doped graphenes. Finally, we propose possible design principles for WFC of VOCs interacting with N-doped graphene materials. [ABSTRACT FROM AUTHOR]

Molecular stacking behavior exerts a significant influence on the blend film morphology of organic solar cells (OSCs), further affecting device performance and stability. Modulation of the molecular structure, such as central unit and end‐group, can profoundly impact this process. Herein, four quinoxaline (Qx)‐fused‐core‐based non‐fullerene acceptors (NFAs), Qx‐N4F and Qx‐o/m/p‐N4F are synthesized combining π‐extended end‐groups and optimized central units. The isomeric fluorinated central units lead to changes in the local dipole moments and electrostatic potential distribution, which influences the molecular stacking pattern and photoelectronic properties of NFAs. Consequently, binary and ternary devices based on PM6:Qx‐p‐N4F achieve superior power conversion efficiencies (PCE) of up to 18.75% and 19.48%, respectively. Grazing‐incidence wide‐angle X‐ray scattering (GIWAXS) characterization reveals Qx‐p‐N4F's stronger crystallinity, aggregation, and donor–acceptor interactions, which can separately enhance short‐circuit current density (JSC) and fill factor (FF) through higher phase purity and tighter molecular stacking based on maintaining more donor–acceptor interfaces. Furthermore, PM6:Qx‐p‐N4F‐based devices demonstrate exceptional thermal stability, retaining 93.2% of the initial PCE value after 3000 h of heating due to the best morphological stability with the most stable stacking structure. These results underscore the significance of synergistic optimization of NFAs through conjugation expansion and halogenation substitution for obtaining efficient and stable OSCs. [ABSTRACT FROM AUTHOR]

High‐level multireference and coupled cluster quantum calculations were employed to analyze low‐lying electronic states of linear‐MNX+ and side‐bonded‐M[NX]+ (M = Ca, Sr, Ba, Ra; X = O, S, Se, Te, Po) species. Their full potential energy curves (PECs), dissociation energies (Des), geometric parameters, excitation energies (Tes), and harmonic vibrational frequencies (ωes) are reported. The first three chemically bound electronic states of MNX+ and M[NX]+ are 3∑−, 1Δ, 1∑+ and 3A″, 1A′, 1A″, respectively. The 3∑−, 1Δ, 1∑+ of MNX+ originate from the M+(2D) + NX(2Π) fragments, whereas the 3A″, 1A′, 1A″ states of M[NX]+ dissociate to M+(2S) + NX(2Π) as a result of avoided crossings. The MNX+ and M[NX]+ are real minima on the potential energy surface and their interconversions are possible. The M2+NX−/M2+[NX]− ionic structure is an accurate representation for their low‐lying electronic states. The Des of MNX+ species were found to depend on the dipole moment (μ) of the corresponding NX ligands and a linear relationship between these two parameters was observed. [ABSTRACT FROM AUTHOR]

The reversibility and stability of zinc (Zn) metal anode are closely related to inner Helmholtz plane (IHP) chemistry. The H2O‐rich IHP raises severe parasitic reactions and irregular Zn deposition, impeding the practical utility of Zn anode in aqueous Zn‐ion batteries (AZIBs). In this study, tetrahydropyran (THP), a five‐carbon heterocyclic ether with permanent dipole moment and hydrophobic characteristic, is introduced as a self‐adsorptive additive to reshape the IHP. It squeezes out partial H2O molecules and forms a H2O‐lean IHP, benefitting for alleviating active H2O decomposition and improving the stability of Zn anode. Moreover, the adsorbed THP induces the preferential nucleation of Zn (002) plane, facilitating dendrite‐free growth and improving the reversibility of Zn anode. Consequently, the Zn||Zn symmetric cell enables to cycle over 3600 h at 5 mA cm−2@ 1 mAh cm−2. The Zn||Cu half‐cell can stably cycle over 400 cycles with 99.9% coulombic efficiency even under harsh test conditions (10 mA cm−2@5 mAh cm−2) with 30 µm Zn foil. The Zn||NH4V4O10 full cell maintains 92.6% capacity retention after 800 cycles at 1 A g−1 and the Zn||I2 full cell enables to perform steadily over 10000 cycles with a capacity decay rate of merely 0.003% per cycle at 5 C. [ABSTRACT FROM AUTHOR]

Following the rapid development of information technology, modern polarized light, which is a critical component for display and data transmission, has been in demand for miniaturization and high efficiency, rendering two‐dimensional (2D) semiconductors potential candidates. The traditional polarized light is usually generated by external optical structures or polarizers that influence the scaling and bring up losses. Previous works have reported polarized light emission from inversion‐asymmetric 2D semiconductors such as black phosphorus (BP), black arsenide phosphorus (AsP), and rhenium disulfide (ReS2), however, their emission wavelengths are not in the visible range. Here, a direct emission of linearly polarized light is demonstrated from van der Waals light–emitting diodes (vdWLEDs) via the flexoelectric effects by inducing the non‐uniform strain in monolayer (ML) transition metal dichalcogenides (TMDCs). In this work, the effects of strain including excitonic binding energy and exciton dipole moment distribution is analyzed by the density functional theory (DFT) then we show that linearly polarized photoluminescence (PL) with a degree of linear polarization (DOLP) of ≈17% can be realized at room temperature (RT), and the polarization angle is perpendicular to the direction of the strain‐gradient. By incorporating the strained ML TMDCs into vdWLEDs, electroluminescence (EL) with DOLP of ≈19% can be observed at RT. This work puts forward a direct and universal strategy for fabricating polarized LEDs based on inversion‐symmetric semiconductors. [ABSTRACT FROM AUTHOR]

Asymmetric non‐fullerene small molecules acceptor (as‐NF‐SMAs) exhibit greater vitality in photovoltaic materials compared to their symmetric counterparts due to their larger dipole moments and stronger intermolecular interactions, which facilitate exciton dissociation and charge transmission in organic solar cells (OSCs). Here, we introduced a new as‐NF‐SMAs, named IDT‐TNIC, as the third component in ternary organic solar cells (TOSCs). The asymmetric IDT‐TNIC used indacenodithiophene (IDT) as the central core, alkylthio‐thiophene as a unilateral π‐bridge and extended end groups as electron‐withdrawing. Due to the non‐covalent conformational lock (NCL) established between O⋅⋅⋅S and S⋅⋅⋅S, the IDT‐TNIC molecule preserves its coplanar structure effectively. Furthermore, IDT‐TNIC exhibits complementary absorption and excellent compatibility with donor and acceptor materials, as well as optimized ladder energy level arrangement, resulting in a higher and more balanced μh/μe value, more homogeneous and suitable phase separation morphology in TOSCs. Thus, the PCE of the TOSCs reached 17 % when the weight ratio of PM6 : Y6 : IDT‐TNIC was 1 : 1.1 : 0.1, and it is noteworthy that when the device area was increased to 1 cm2, the PCE could still be maintained at over 14 %. Detailed studies and analysis indicate that IDT‐TNIC has great potential as a third component in OSCs and for large‐scale printing in the future. [ABSTRACT FROM AUTHOR]

Breaking the trade‐off between broad spectrum response and efficient charge separation is a major challenge in the photocatalysis. Unlike the conventional practice of suppressing charge separation when shrinking the bandgap, a series of deacetylated chitin‐perylene diimide (DC‐PDI) donor–acceptor (D–A) photocatalysts is proposed with tunable charge distribution by modulating the C─N covalent bond content, expanding the spectral absorption range as the expanded D–A. The enlarged D–A structure achieves efficient photogenerated electron–hole separation by increasing the charge of the positive and negative charge centers, inducing larger dipole moments, generating 4.7 times higher built‐in electric field, and reducing the charge transfer barrier. Among them, the optimum DC/PDI (2:1) with enlarged D–A enables to capture the largest number of electrons for persulfate activation, and concurrently affords the highest hole generation efficiency with the deepest valence band (1.67 V). Such merits contribute to 1.2–2.8 times higher degradation rate and 1.1–1.6 times higher mineralization rate of organic pollutants in comparison with other counterparts. The mineralization rate can reach 100% in the engineered microreactor setup. This study elucidates the structure‐mechanism‐performance relationship of D–A modulation and charge separation/transport, guiding the rational molecular structure design for efficient photocatalytic oxidation. [ABSTRACT FROM AUTHOR]

This study systematically investigated the influence of substituents (NH2, CH3, CF3, and Cl) on the keto-enol tautomerism of 1,2-cyclodiones, focusing on reactivity and thermodynamic stability. Calculations were performed using the M06-2X/6-311G++** level of theory, with a solvation model through CPCM/M06-2X/6-311G++**. Results indicate ring-size dependent tautomerism, with three-, five-, and six-membered rings favouring the keto-enol form, while four- and seven-membered rings favour the diketo form. The NH2 substituent uniquely stabilised the keto-enol form. Electron-donating groups generally stabilised the keto-enol form. Contrary to common expectations, a direct correlation between dipole moment and stability order was not universally observed within 1,2-cyclodione systems, with the NH2 group demonstrating nuanced effects. Similarly, dipole moment and electrostatic potential variance did not exhibit consistent correlation under the influence of different substituents. The diketo tautomer was generally found to be more reactive than the keto-enol form, especially in non-polar solvents. Surprisingly, substituent groups decreased the reactivity of the diketo form relative to the unsubstituted compound. [ABSTRACT FROM AUTHOR]

Supercritical water has attracted much attention from both fundamental and technological perspectives, based largely on its ability to solvate other molecules. Predicting and controlling this requires a deeper understanding of water's polarisation behaviour. Using the computationally efficient Self-Consistent Electrostatic Embedding method, we were able to calculate the water dipole moment over an unprecedented range of thermodynamic conditions, covering gas, liquid and supercritical states, with large simulation systems and a high-level quantum mechanical method. We find a discontinuous change in the dipole moment along subcritical isotherms, corresponding to the sharp transition between the vapour and liquid states, with the latter exhibiting induced dipole moments between 0.5 and 0.9 D, depending on the temperature. In contrast, the dipole moment changes continuously from gas-like to liquid-like behaviour in the supercritical regime, allowing the degree of polarisation to be controlled through manipulating temperature and pressure. The dipole moment was found to be linearly related to the average number of hydrogen-bonded neighbours of water, emphasising the key role of local interactions to the polarisation process. Mean-field approaches based on a dielectric continuum representation of the solvent are unable to predict this behaviour due to the neglect of local interactions. [ABSTRACT FROM AUTHOR]

Neutral and zwitter-ionic conformers of glycine (Gly) and alanine (L-Ala) are quantum chemically calculated at the B3LYP+GD3/def2TZVPP level of density functional theory within the discrete-continuum model in the gas phase and with regard to the effect of the aqueous medium. Structures with the minimum dipole moments prove to be the most stable neutral conformers of Gly and Ala in the gas phase. When solvation effects are taken into account within the polarized continuum model, conformers with the maximum dipole moments become energetically favorable due to the dipole-dipole interaction with the medium. Reaction activation barriers of the intramolecular proton transfer in the formation of zwitter-ions studied are calculated depending on the number of water molecules in the first coordination sphere. The inclusion of seven water molecules saturating the hydrogen bond of – and –COO– functional groups into the discrete-continuum model of a water solvent is shown to significantly decrease the activation barrier to 0.02 kcal/mol for glycine and to 0.09 kcal/mol for alanine. [ABSTRACT FROM AUTHOR]

[Display omitted] We demonstrate that machine learning models trained on a set of features obtained from QM/MM molecular dynamic trajectories of fluorescent proteins can be used to predict the chromophore dipole moment variation upon excitation, the quantity related to the electronic excitation energy. Linear regression, gradient boosting, and artificial neural network- based models were considered using cross-validation on the training dataset. Gradient boosting approach proved to be the most accurate for both internal (R2 = 0.77) and external (R2 = 0.7) test sets. [ABSTRACT FROM AUTHOR]

Multi‐resonant thermally activated delayed fluorescence (MR‐TADF) helicenes show great potential as chiral emitters due to their typically high photoluminescence quantum yield and that they emit circularly polarized luminescence. Here, a new propeller‐shaped chiral MR‐TADF helicene DiKTa3, integrating three DiKTa moieties, was designed and synthesized aiming to achieve co‐parallel electronic and magnitude transition dipole moments that would lead to a high dissymmetry factor, g. It emits at λPL of 491 nm, with a full width at half maximum of 52 nm and has a moderate ΔEST value of 0.24 eV in toluene. The separated (P,P,P) enantiomer shows an absorption dissymmetry factor |gabs| of 6.8×10−4 at 450 nm, which results from a lower symmetry conformation adopted by the compound in solution than the C3‐symmetric optimized structure. This work highlights the strong influence that geometry can have on the chiroptical properties of the emitter. [ABSTRACT FROM AUTHOR]

This study utilises a combination of density functional theory (DFT) approach, 6-31G (d, p) basis set, and Monte Carlo (MC) simulations. The goal is to understand the relationship between the structure and properties of heterocyclic inhibitors and how they interact with Fe (110) surfaces. Furan, pyrrole, thiophene, pyridine, pyridazine, pyrimidine, indole, benzofuran, carbazole, quinolone, isoquinoline, and imidazole are the chemicals that were looked at in this study. The DFT calculations provide important insights into various properties of the inhibitors, such as molecular structure, dipole moments, electrostatic potential maps, Reduced Density Gradient (RDG), UV spectroscopy, and thermal characteristics. Carbazole has the smallest energy difference (4.789 eV) and the highest softness (0.209 eV−1), It also has the most chemical activity, Furthermore, the Monte Carlo models demonstrate that these derivatives have favourable adsorption energies on the Fe (110) surface. Among them, carbazole shows significant inhibitory potential. The study confirms that the carbazole compound with the biggest negative adsorption energy (−95.495) actually has the smallest energy difference and fits with the MC simulation for adsorption on Fe (110) when it is not charged. Carbazole has much stronger adsorption than oxazole, showing how the structure of a molecule affects how well an inhibitor works. [ABSTRACT FROM AUTHOR]

Data on the absolute value of the geomagnetic field intensity at the beginning of the Cretaceous Normal Superchron (C34n) was obtained from basalts of Hooker Island of the Franz Josef Land archipelago (FJL). These basalts are considered as one of the manifestations of the High Arctic Large Igneous Province. The record of the ancient geomagnetic field in the studied Early Cretaceous basalts was preserved well due to the presence of pseudo-single domain grains of primary magmatic titanomagnetite. The paleointensity, obtained by the Thellier–Coe method, satisfies the generally accepted reliability criteria, taking into consideration other necessary evidence. This information indicates that 125 Ma, during the formation of the FJL traps, the intensity of the geomagnetic field was four times lower than today. Our estimates show that the mean value of the virtual dipole moment was 1.7 × 1022 Am2. These results support the views about the low paleointensity at the Barremian–Aptian boundary and indicate a correlation between the intensity of the geomagnetic field, the frequency of reversals, and the formation of mantle plumes. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Macrocyclic compounds are of great interest for their ability to capture guest molecules into their cavities. In particular, host‐guest interaction plays a crucial role in the formation of supramolecular compounds. Herein, two host‐guest supramolecular compounds, [Al8(OH)8(L)16]·2HL (HL@AlOC‐166, HL = 4‐Iodobenzoic acid) and [Al8(OH)8(L)8(L1)8]·2DMF (DMF@AlOC‐166, HL1 = isoamyl alcohol), are acquired by introducing different types of guest components based on the internal pore cavities of the aluminum molecular ring [Al8(OH)8(L)16] (AlOC‐166). The inclusion of these guests is attributed to the presence of abundant hydrophilic OH serving as the hydrogen bond donors inward the ring cavity. Host‐guest compounds usually exhibit superior nonlinear optical (NLO) response due to the existence of guest molecules that could change symmetry, dipole moments, charge distributions, etc. Unexpectedly, the AlOC‐166 achieved the best NLO results, although it had no guest molecules inside its molecular ring, which breaks the traditional concept. The reason for this trend can be explained by the difference in intermolecular force rather than intramolecular interaction, mainly related to the amount and strength of π···π and C—I···π interactions in different compounds. This work investigates the effect of host‐guest interaction on NLO, representing a new perspective for designing optical limiting materials. [ABSTRACT FROM AUTHOR]

Organic compounds pose significant environmental concerns, including groundwater contamination. Clays are commonly used as liners to prevent contaminant permeation into the groundwater tables, necessitating an understanding of clay's behavior in the presence of organic compounds. The presence of organic contaminants results in changes in the dielectric constant of pore fluid, which influences the interparticle energies and double layer thickness in the soil-pore fluid system. This study aims to elucidate the mechanisms of these changes by examining the response of smectite and kaolinite to variations in the dielectric constant. Experimental tests, including Atterberg limits, unconfined compression strength, water adsorption, sedimentation, pH, and XRD, were performed on clay samples at different concentrations of water-isopropyl alcohol mixtures. Results indicate that smectite exhibits higher Atterberg limits and water adsorption capacity compared to kaolinite. Smectite also shows more pronounced changes in response to decreasing dielectric constant. Conversely, changes in kaolinite's behavior were attributed to variations in pore fluid viscosity and dipole moment. These findings emphasize the importance of considering viscosity and dipole moment alongside dielectric constant in predicting kaolinite behavior. Overall, this study enhances the understanding of how variations in pore fluid dielectric constant affect the geotechnical and geo-environmental behavior of smectite and kaolinite. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Macrocyclic compounds are of great interest for their ability to capture guest molecules into their cavities. In particular, host‐guest interaction plays a crucial role in the formation of supramolecular compounds. Herein, two host‐guest supramolecular compounds, [Al8(OH)8(L)16]·2HL (HL@AlOC‐166, HL = 4‐Iodobenzoic acid) and [Al8(OH)8(L)8(L1)8]·2DMF (DMF@AlOC‐166, HL1 = isoamyl alcohol), are acquired by introducing different types of guest components based on the internal pore cavities of the aluminum molecular ring [Al8(OH)8(L)16] (AlOC‐166). The inclusion of these guests is attributed to the presence of abundant hydrophilic OH serving as the hydrogen bond donors inward the ring cavity. Host‐guest compounds usually exhibit superior nonlinear optical (NLO) response due to the existence of guest molecules that could change symmetry, dipole moments, charge distributions, etc. Unexpectedly, the AlOC‐166 achieved the best NLO results, although it had no guest molecules inside its molecular ring, which breaks the traditional concept. The reason for this trend can be explained by the difference in intermolecular force rather than intramolecular interaction, mainly related to the amount and strength of π···π and C—I···π interactions in different compounds. This work investigates the effect of host‐guest interaction on NLO, representing a new perspective for designing optical limiting materials. [ABSTRACT FROM AUTHOR]

Many low-cost or semiempirical quantum mechanical-based electronic structure methods suffer from the use of unpolarized minimal atomic orbital (AO) basis sets. In this work, we overcome this limitation by a fully DFT variationally optimized, adaptive minimal basis set consistently available for the elements up to radon (Z = 86). The new key feature is to make the linear coefficients of the primitive Gaussians in a contracted AO dependent on the effective atomic charge of the atom in the molecule, i.e., each symmetry-unique atom obtains its "own" specifically adapted basis functions. In this way, the physically important "breathing" of the AOs in a molecule with (a) atomic charge (expansion/contraction for anionic/cationic states) and (b) the number of close-lying bonded neighbor atoms is accounted for. The required atomic charges are obtained from a specially developed extended Hückel type Hamiltonian and the coordination numbers from the molecule geometry. Proper analytical derivatives of the resulting adaptive basis functions can easily be derived. Moreover, the basis functions are electric field-dependent, thus improving the description of, e.g., dipole moments and polarizabilities. The new basis set termed q-vSZP (charge dependent valence single-ζ, polarized) is thoroughly benchmarked for atomic/molecular and thermochemical properties compared to standard minimal and double-ζ basis sets at the DFT level with the accurate ωB97X-D4 functional. It is shown that q-vSZP is clearly superior to existing minimal basis sets, often reaching double-ζ quality or even better results. We expect it to be the optimal choice in future semiempirical quantum mechanical methods. [ABSTRACT FROM AUTHOR]

Atomic layer deposition is a key technique for preparing large area uniformity, three-dimensional conformal, and ultrathin films due to its sequential self-limiting saturated chemisorption properties. Electric fields of varying magnitudes and directions were applied on Si, Al2O3, Au, and Ni substrates in Pt plasma enhanced atomic layer deposition processes. Studying the influences of electric fields on the initial nucleation and growth of Pt films on different substrates helps to understand the dynamic knowledge and underlying physical mechanisms so as to obtain ultrathin, continuous films and full control over the morphology and distribution of deposited materials. The XPS results reveal that the Pt coverage rate increases on all substrates with applied voltages. The induced dipole moment causes the (MeCp)PtMe3 molecule to rotate in a certain direction resulting in a more compact arrangement, and the energy generated by electric fields also helps the dissociation of methyl, ethyl, Cp, and MeCp ligands, which greatly mitigate the spatial site resistance effect, thus improving initial monolayer chemisorption efficiency and the Pt coverage. We also find that Pt prefers to grow in the (111) direction due to the increase in adsorption of (MeCp)PtMe3 molecules caused by the gradient forces under electric fields. However, applied electric fields can also influence the morphology by inducing surface diffusion and acting on plasma species. [ABSTRACT FROM AUTHOR]

We develop a Stockmayer fluid model that accounts for the dielectric responses of polar solvents (water, MeOH, EtOH, acetone, 1-propanol, DMSO, and DMF) and NaCl solutions. These solvent molecules are represented by Lennard-Jones (LJ) spheres with permanent dipole moments and the ions by charged LJ spheres. The simulated dielectric constants of these liquids are comparable to experimental values, including the substantial decrease in the dielectric constant of water upon the addition of NaCl. Moreover, the simulations predict an increase in the dielectric constant when considering the influence of ion translations in addition to the orientation of permanent dipoles. [ABSTRACT FROM AUTHOR]

We report the experimental resonance enhanced multiphoton ionization spectrum of isoquinoline between 315 and 310 nm, along with correlated electronic structure calculations on the ground and excited states of this species. This spectral region spans the origin transitions to a π–π* excited state, which previous work has suggested to be vibronically coupled with a lower lying singlet n–π* state. Our computational results corroborate previous density functional theory calculations that predict the vertical excitation energy for the n–π* state to be higher than the π–π* state; however, we find an increase in the C–N–C angle brings the n–π* state below the energy of the π–π* state. The calculations find two out-of-plane vibrational modes of the n–π* state, which may be brought into near resonance with the π–π* state as the C–N–C bond angle increases. Therefore, the C–N–C bond angle may be important in activating vibronic coupling between the states. We fit the experimental rotational contour with a genetic algorithm to determine the excited state rotational constants and orientation of the transition dipole moment. The fits show a mostly in-plane polarized transition, and the projection of the transition dipole moment in the a-b plane is about 84° away from the a axis. These results are consistent with the prediction of our electronic structure calculations for the transition dipole moment of the π–π* excited state. [ABSTRACT FROM AUTHOR]

Charge injection at metal/polymer interfaces is a critical process in many technological devices, including high voltage capacitors and cables in which polyolefin materials, such as polyethylene (PE) and polypropylene (PP), are often used as insulation materials. We use simulations based on density-functional theory to study charge injection at aluminum/PE and aluminum/PP interfaces. Specifically, we investigate the influence of incorporating a variety of polar chemical impurities at the PE and PP chain ends on electron and hole injection barriers. Crucially, we account for the effect of thermal disorder by considering ensembles of thousands of interface structures obtained from ab initio molecular dynamics trajectories at 373 K. We show that the mean injection barrier can change by up to 1.1 eV for Al/PE and 0.6 eV for Al/PP, as compared to the pristine case, depending on which chemical impurity is introduced. We also show that the spread of injection barriers from thermal fluctuations also depends strongly on the chemistry of the impurity. The observed trends can be understood with a simple model based on thermal fluctuations of the dipole moment density associated with the chemical impurity at the interface. We further verify this model by considering larger interface models with lower impurity densities. Our results demonstrate that small chemical modifications, which may arise from oxidation, for example, have a significant influence on charge injection barriers in metal/polyolefin interfaces. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) transition metal dihalides (TMDHs) have attracted great interest owing to their unique magnetic and semiconductor properties. Compared with the mirror/inversion symmetric materials, 2D Janus materials possess vertical intrinsic dipole moment, which offer a versatile platform for the fundamental physics and future spintronic devices. Here, we systematically explore the magnetic and electronic properties of the 2D Janus transition metal dihalides MXY (M = Co and Ni; X ≠ Y = Cl, Br, and I) monolayers and bilayers by using density functional theory. The monolayer CoClBr, NiClBr, and NiBrI are bipolar ferromagnetic semiconductors that possess the valence and conduction band edges of different spin channels. The magnetism of the bilayer CoClBr, NiClBr, and NiBrI is highly dependent on the accumulated dipole moments of the two adjacent layers. When the dipole moments in both layers are aligned in the same direction and the accumulated dipole moments are nonzero, the systems are antiferromagnetic half semiconductors. However, when the dipole moments in the two layers are opposite and the accumulated dipole moments are zero, the systems are A-type antiferromagnetic semiconductors. Our findings are helpful to understand the magnetism of Janus TMDHs and guide experiments in exploring their potential application in spintronic devices. [ABSTRACT FROM AUTHOR]

Temperature gradients induce mass separation in mixtures in a process called thermal diffusion and are quantified by the Soret coefficient ST. Thermal diffusion in fluid mixtures has been interpreted recently in terms of the so-called (pseudo-)isotopic Soret effect but only considering the mass and moment of inertia differences of the molecules. We demonstrate that the first moment of the molecular mass distribution, the mass dipole, contributes significantly to the isotopic Soret effect. To probe this physical effect, we investigate fluid mixtures consisting of rigid linear molecules that differ only by the first moment of their mass distributions. We demonstrate that such mixtures have non-zero Soret coefficients in contrast with ST = 0 predicted by current formulations. For the isotopic mixtures investigated in this work, the dependence of ST on the mass dipole arises mainly through the thermal diffusion coefficient DT. In turn, DT is correlated with the dependence of the molecular librational modes on the mass dipole. We examine the interplay of the mass dipole and the moment of inertia in defining the isotopic Soret effect and propose empirical equations that include the mass dipole contribution. [ABSTRACT FROM AUTHOR]

The analysis and modeling of high-resolution spectra of nonrigid molecules require a specific Hamiltonian and group-theoretical formulation that differs significantly from that of more familiar rigid systems. Within the framework of Hougen–Bunker–Johns (HBJ) theory, this paper is devoted to the construction of a nonrigid Hamiltonian based on a suitable combination of numerical calculations for the nonrigid part in conjunction with the irreducible tensor operator method for the rigid part. For the first time, a variational calculation from ab initio potential energy surfaces is performed using the HBJ kinetic energy operator built from vibrational, large-amplitude motion, and rotational tensor operators expressed in terms of curvilinear and normal coordinates. Group theory for nonrigid molecules plays a central role in the characterization of the overall tunneling splittings and is discussed in the present approach. The construction of the dipole moment operator is also examined. Validation tests consisting of a careful convergence study of the energy levels as well as a comparison of results obtained from independent computer codes are given for the nonrigid molecules CH2, CH3, NH3, and H2O2. This work paves the way for the modeling of high-resolution spectra of larger nonrigid systems. [ABSTRACT FROM AUTHOR]

Using Bayesian spectroscopy, we performed spectral decomposition of gate modulation (GM) spectra measured in a pentacene organic field-effect transistor to understand comprehensively the optical nonlinear response due to GM and hole injection. Although GM spectra contain a variety of spectral components, by Bayesian spectroscopy, we can specify the role of each component in the nonlinear response by performing model selection that chooses the spectral components needed to explain the data without preconceptions. For a GM spectrum under positive GM, Bayesian spectroscopy shows that nonlinear responses by the change in polarizability dominate the GM spectrum among several types of Stark signals induced by the GM electric field, which is a physically valid conclusion. For GM spectra under negative GM where gate-induced carriers are injected, Bayesian spectroscopy succeeds in completely elucidating the spectral structure, which is composed of the two types of Stark signals due to changes in the polarizability and the dipole moment, bleaching, and gate-induced absorption signals. A pentacene film is known to have solid and isolated molecular phases, which may give different spectral responses. Therefore, we compared a model that treats these responses equally and a model that distinguishes them. Bayesian spectroscopy selects the latter models for all GM spectra, revealing statistically that nonlinear optical effects and hole injection effects are different in these phases. [ABSTRACT FROM AUTHOR]

A pulse-shaping technique in the mid-infrared spectral range based on pulses with a super-Gaussian temporal profile is considered for laser control. We show a realistic and efficient path to the population of a dark rovibrational state in acetylene (C2H2). The laser-induced dynamics in C2H2 are simulated using fully experimental structural parameters. Indeed, the rotation–vibration energy structure, including anharmonicities, is defined by the global spectroscopic Hamiltonian for the ground electronic state of C2H2 built from the extensive high-resolution spectroscopy studies on the molecule, transition dipole moments from intensities, and the effects of the (inelastic) collisions that are parameterized from line broadenings using the relaxation matrix [A. Aerts, J. Vander Auwera, and N. Vaeck, J. Chem. Phys. 154, 144308 (2021)]. The approach, based on an effective Hamiltonian, outperforms today's ab initio computations both in terms of accuracy and computational cost for this class of molecules. With such accuracy, the Hamiltonian permits studying the inner mechanism of theoretical pulse shaping [A. Aerts et al., J. Chem. Phys. 156, 084302 (2022)] for laser quantum control. Here, the generated control pulse presents a number of interferences that take advantage of the control mechanism to populate the dark state. An experimental setup is proposed for in-laboratory investigation. [ABSTRACT FROM AUTHOR]

The nature of the second excited state in a quadrupolar molecule of the A–D–A structure, where A and D are an electron acceptor and an electron donor, respectively, has been studied. The orthogonality condition of the wave functions requires that the direction of the molecular dipole moment arising due to the charge transfer symmetry breaking be opposite in the first and second excited states. The dipole moment flip leads to large reorganization energy of the solvent upon excited state absorption. The manifestations of dipole flip are discussed. The dependence of the energy gap on the solvent polarity is found. The symmetry breaking effect on the transition dipole moment suppression is calculated. The available experimental data confirm the main conclusions. [ABSTRACT FROM AUTHOR]