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The application of template crystallization to developing novel crystalline materials has attracted attention. However, when the air–solution interface becomes the template interface and the target material crystallizes, new nucleation at the template interface is prevented, which is predicted to prevent the increase in the total number of crystals. In this study, we investigated the effect of operations that change the driving force at the air–solution template interface on the number of crystals at the interface. The number of crystals precipitated by changing the local supersaturation was investigated by a novel "template reset" operation, in which the concentration driving force near the template interface is changed by dissolving the crystals at the interface, once precipitated. The results showed that the number of crystals increased significantly after the template reset operation, and the particle size distribution was also improved. The temperature of the solution near the interface after the template reset operation was higher than that of the solution at the bottom of the petri dish and the prepared saturated solution, suggesting that the driving force of crystallization was higher. [ABSTRACT FROM AUTHOR]

Conventional elastomers, such as polyisoprene, polybutadiene, and styrene–butadiene rubber, lack inherent shape memory properties due to their low glass transition temperature. Recently, researchers have discovered a method to incorporate external crystal moieties, thereby transforming these elastomers into thermoresponsive shape memory polymers. However, the question remains: what possibilities might this revolution unfold in the near future? This brief opinion piece celebrates the development of semi‐crystalline shape memory elastomers developed via grafting crystals onto conventional elastomers and offers personal insights into the potential directions this discovery could take us. [ABSTRACT FROM AUTHOR]

Cadmium germanium diphosphide (CdGeP2) crystals, with versatile terahertz-generating properties, belong to the chalcopyrite family of nonlinear optical materials. Other widely investigated members of this family are ZnGeP2 and CdSiP2. The room-temperature absorption edge of CdGeP2 is near 1.72 eV (720 nm). Cadmium vacancies, phosphorous vacancies, and germanium-on-cadmium antisites are present in as-grown CdGeP2 crystals. These unintentional intrinsic point defects are best studied below room temperature with electron paramagnetic resonance (EPR) and optical absorption. Prior to exposure to light, the defects are in charge states that have no unpaired spins. Illuminating a CdGeP2 crystal with 700 or 850 nm light while being held below 120 K produces singly ionized acceptors ( V Cd −) and singly ionized donors ( Ge Cd +), as electrons move from V Cd 2 − vacancies to Ge Cd 2 + antisites. These defects become thermally unstable and return to their doubly ionized charge states in the 150–190 K range. In contrast, neutral phosphorous vacancies ( V P 0) are only produced with near-band-edge light when the crystal is held near or below 18 K. The V P 0 donors are unstable at these lower temperatures and return to the singly ionized V P + charge state when the light is removed. Spin-Hamiltonian parameters for the V Cd − acceptors and V P 0 donors are extracted from the angular dependence of their EPR spectra. Exposure at low-temperature to near-band-edge light also introduces broad optical absorption bands peaking near 756 and 1050 nm. A consistent picture of intrinsic defects in II-IV-P2 chalcopyrites emerges when the present CdGeP2 results are combined with earlier results from ZnGeP2, ZnSiP2, and CdSiP2. [ABSTRACT FROM AUTHOR]

Forward flux sampling (FFS) is a path sampling technique widely used in computer simulations of crystal nucleation from the melt. In such studies, the order parameter underpinning the progress of the FFS algorithm is often the size of the largest crystalline nucleus. In this work, we investigate the effects of two computational aspects of FFS simulations, using the prototypical Lennard-Jones liquid as our computational test bed. First, we quantify the impact of the positioning of the liquid basin and first interface in the space of the order parameter. In particular, we demonstrate that these choices are key to ensuring the consistency of the FFS results. Second, we focus on the frequently encountered scenario where the population of crystalline nuclei is such that there are multiple clusters of size comparable to the largest one. We demonstrate the contribution of clusters other than the largest cluster to the initial flux; however, we also show that they can be safely ignored for the purposes of converging a full FFS calculation. We also investigate the impact of different clusters merging, a process that appears to be facilitated by substantial spatial correlations—at least at the supercooling considered here. Importantly, all of our results have been obtained as a function of system size, thus contributing to the ongoing discussion on the impact of finite size effects on simulations of crystal nucleation. Overall, this work either provides or justifies several practical guidelines for performing FFS simulations that can also be applied to more complex and/or computationally expensive models. [ABSTRACT FROM AUTHOR]

The application of rare earth (RE) doped crystals in quantum information processing has attracted more and more attention in the past decade. How to change the clock transitions of RE ion in crystal and control their lifetime of maintaining coherent quantum state is a valuable question. In this work, the trigonal 171Yb3+ centers in lithium niobate (LN) crystal are investigated theoretically to obtain their accurate ground and excited hyperfine sublevels under external magnetic field B by a combined method of density functional theory-based geometric optimization and parametric effective Hamiltonian modeling. An optical clock transition at |B| = 45.73 mT along the c axis of the LN crystal is successfully found by calculation. To show the pressure-dependent behavior of optical clock transition, the variation of such transition under hydrostatic pressure up to 3 GPa is also obtained theoretically. The calculated results show that applying external pressure is an effective way to control these transitions of RE ion doped crystal. Moreover, the optical coherence time T2 at zero magnetic field for 171Yb3+ ion with C3 symmetry in the LN crystal is estimated by our calculations. The calculated results indicate that if the magnetic field noise is 33 μT in the LN crystal, it is possible to find an optical clock transition with long coherence time T2 (≈382 μs) at the zero magnetic field. The present methods of seeking optical clock transition and calculating its coherence time T2 caused by a fluctuating magnetic field noise in the host crystal can be applied to other Kramers RE ions doped materials. [ABSTRACT FROM AUTHOR]

The most accepted origin for the water anomalous behavior is the phase transition between two liquids (LLPT) in the supercooled regime connected to the glassy first order phase transition at lower temperatures. Two length scale potentials are an effective approach that has long been employed to understand the properties of fluids with waterlike anomalies and, more recently, the behavior of colloids and nanoparticles. These potentials can be parameterized to have distinct shapes, as a pure repulsive ramp, such as the model proposed by de Oliveira et al. [J. Chem. Phys. 124, 64901 (2006)]. This model has waterlike anomalies despite the absence of LLPT. To unravel how the waterlike anomalies are connected to the solid phases, we employ molecular dynamics simulations. We have analyzed the fluid–solid transition under cooling, with two solid crystalline phases, BCC and HCP, and two amorphous regions being observed. We show how the competition between the scales creates an amorphous cluster in the BCC crystal that leads to amorphization at low temperatures. A similar mechanism is found in the fluid phase, with the system changing from a BCC-like to an amorphous-like structure in the point where a maxima in kT is observed. With this, we can relate the competition between two fluid structures with the amorphous clusterization in the BCC phase. These findings help to understand the origins of waterlike behavior in systems without the liquid–liquid critical point. [ABSTRACT FROM AUTHOR]

Elastic stability criteria are widely employed to prove the being of the lattice. Sin'ko and Smirnov have reported the applicable criteria under isotropic pressure and given the equations between the elastic constants C ~ i j and C i j under pressure. On this basis, the closed forms of necessary and sufficient conditions for elastic stability in all crystal classes have been presented, which are popular in normal pressure. However, the forms of elastic stability criteria under pressure are still fragmented in various literature studies. Carbon is an element with a rich variety of allotropes, and because of its excellent mechanical and electronic properties, it gains enduring and intense attention, while its phase diagram is poorly known. In order to systematically study the response of various carbon stabilities to pressure and offer some valuable insights into experimental exploration, we derive the total forms of mechanical stability criteria under isotropic pressure and calculate the mechanical stability of 46 carbon allotropes involving seven crystal systems under pressure. [ABSTRACT FROM AUTHOR]

Calcium oxalate (CaOx) crystal deposition in acute kidney injury (AKI) patients is under recognized but impacts renal outcomes. This study investigates its determinants and effects. We studied 814 AKI patients with native kidney biopsies from 2011 to 2020, identifying CaOx crystal deposition severity (mild: <5, moderate: 5–10, severe: >10 crystals per section). We assessed factors like urinary oxalate, citrate, urate, electrolytes, pH, tubular calcification index, and SLC26A6 expression, comparing them with creatinine-matched AKI controls without oxalosis. We analyzed how these factors relate to CaOx severity and their impact on renal recovery (eGFR < 15 mL/min/1.73 m2 at 3-month follow-up). CaOx crystal deposition was found in 3.9% of the AKI cohort (32 cases), with 72% due to nephrotoxic medication-induced tubulointerstitial nephritis. Diuretic use, higher urinary oxalate-to-citrate ratio induced by hypocitraturia, and tubular calcification index were significant contributors to moderate and/or severe CaOx deposition. Poor baseline renal function, low urinary chloride, high uric acid and urea nitrogen, tubular SLC26A6 overexpression, and glomerular sclerosis were also associated with moderate-to-severe CaOx deposition. Kidney recovery was delayed, with 43.8%, 31.2%, and 18.8% of patients having eGFR < 15 mL/min/1.73 m2 at 4, 12, and 24-week post-injury. Poor outcomes were linked to high urinary α1-microglobulin-to-creatinine (α1-MG/C) ratios and active tubular injury scores. Univariate analysis showed a strong link between this ratio and poor renal outcomes, independent of oxalosis severity. In AKI, CaOx deposition is common despite declining GFR. Factors worsening tubular injury, not just oxalate-to-citrate ratios, are key to understanding impaired renal recovery. [ABSTRACT FROM AUTHOR]

Since the discovery of lasers, high-quality nonlinear optical (NLO) single crystals have served as the foundation for the creation of novel, cutting-edge devices that meet societal demands. Modern optoelectronic applications such as telecommunication lasers, optical fibers, photodiodes, solar cells, etc. favor high-performance nonlinear optical single crystals with improved optical nonlinearity. Organic crystals are extensively explored for these applications because of their high NLO coefficient. This paper deals with the problems and advancements of organic nonlinear optical single crystals. Here, we review the growth and characterizations of various tosylate family crystals from the vast realm of organic single crystals and their potential applications in the field of optoelectronic devices. Various properties like linear and nonlinear optical, thermal, mechanical, and laser damage threshold values for these samples have been summarized. The attempts are made for highlighting how these tosylate (p-Toluenesulfonic acid based) family crystals can be realized into efficient optoelectronic devices by summarizing variously reported cut-off wavelengths and their wide transmission ranges. [ABSTRACT FROM AUTHOR]

Domain randomness is inherent in the fabrication of periodically poled lithium niobate (PPLN). The main cause of such domain randomness in fabrication of PPLN is due to electric poling process. This domain randomness not only impacts the effectiveness of frequency conversion, but also enhances the effectiveness of nonphase matched parasitic processes, which in many cases limits the performance of the device. In this paper, we experimentally demonstrate a nondestructive characterization of domain randomness in PPLN by diffraction-noise pattern with uniform illumination. We measure the domain randomness of PPLN and provide an effective method for poling quality assessment either as good or poor quality of PPLN through this paper. [ABSTRACT FROM AUTHOR]

[Display omitted] • Rare-earth Tb doped Pd 49 Ag 30 Te 4 alloy facilitates selective exposure of (1 1 1) crystal plane. • The doping of Tb accelerates electron transfer, promotes CO 2 adsorption as well as activation, and suppress H 2 evolution. • The introduction of Tb regulates d-band center of Pd 49 Ag 30 Te 4 , weakens the Pd − C bonding ability, and promotes the production of CO. Employing electric energy to convert carbon dioxide (CO 2) into valuable small molecules is a potentially practical method in energy storage and greenhouse gas alleviation. A huge challenge for electrocatalytic CO 2 reduction is to reduce overpotential to improve energy efficiency. Herein, we demonstrate that doping alloy Pd 49 Ag 30 Te 4 (PAT) with rare-earth element Tb is beneficial for selective exposure of (1 1 1) crystal plane, which is a highly active crystal plane for producing carbon monoxide (CO). The as-prepared Tb 2.9 PAT exhibited high electrocatalytic performance with 95.7 % CO faradic efficiency at − 0.8 V (vs RHE), far exceeding that of PAT, and coupled with good durability. In situ spectral study and theoretical calculations disclose that the introduction of Tb regulates the d-band center of PAT alloy, weakens the Pd − C bonding ability, and promotes the desorption of *CO in the rate-determining step. This study provides a method for doping induced selective exposure of crystal face, which provides new idea for improving catalytic performance. [ABSTRACT FROM AUTHOR]

In this paper, we establish a connection between Sisyphus dynamics and the Liénard-II equation through branched Hamiltonians. Sisyphus dynamics stem from a higher-order Lagrangian. Surprisingly, when expressed in terms of velocity, the Sisyphus dynamical equations align closely with the Liénard-II equation. Sisyphus dynamics introduces velocity-dependent "mass functions", a departure from conventional position-dependent mass, potentially linked to cosmological time crystals. Additionally, we demonstrate that spontaneously broken time translational symmetry results in a deformed symplectic structure, resembling the classical counterpart of the Generalized Uncertainty Principle (GUP). [ABSTRACT FROM AUTHOR]

We show that there exists a unique crystal base of a parabolic Verma module over a quantum orthosymplectic superalgebra, which is induced from a q -analogue of a polynomial representation of a general linear Lie superalgebra. [ABSTRACT FROM AUTHOR]

We consider reduced imaginary Verma modules for the untwisted quantum affine algebras U q (g ˆ) and define a crystal-like base which we call imaginary crystal base using the Kashiwara algebra K q constructed in earlier work by Ben Cox and two of the authors. We prove the existence of the imaginary crystal base for any object in a suitable category O r e d , i m q containing the reduced imaginary Verma modules for U q (g ˆ). [ABSTRACT FROM AUTHOR]

With the help of path realization and affine energy function, we give a Young wall construction of level-1 highest weight crystals B (λ) over U q (G 2 (1)) and U q (D 4 (3)). Our construction is based on four different shapes of colored blocks, O -block, I -block, L -block and LL -block, obtained by cutting the unit cube in three different ways. [ABSTRACT FROM AUTHOR]

We construct an injection from the set of r -fans of Dyck paths (resp. vacillating tableaux) of length n into the set of chord diagrams on [ n ] that intertwines promotion and rotation. This is done in two different ways, namely as fillings of promotion matrices and in terms of Fomin growth diagrams. Our analysis uses the fact that r -fans of Dyck paths and vacillating tableaux can be viewed as highest weight elements of weight zero in crystals of type B r and C r , respectively, which in turn can be analyzed using virtual crystals. On the level of Fomin growth diagrams, the virtualization process corresponds to the Roby–Krattenthaler blow up construction. One of the motivations for finding rotation invariant diagrammatic bases such as chord diagrams is the cyclic sieving phenomenon. Indeed, we give a cyclic sieving phenomenon on r -fans of Dyck paths and vacillating tableaux using the promotion action. [ABSTRACT FROM AUTHOR]

The author presents a critical response to S. Pearl Brilmyer's essay "Queer Rigidity: Habit and the Limits of the Performativity Thesis" published in the Summer 2024 issue. Topics include the author's thoughts on the metaphors used by Brilmyer that she argued have undergirded and limited queer theory, his reference to Leslie Feinberg's novel "Stone Butch Blues," and the connection of Brilmyer's habit as rigidity to the crystal that appeared in a sentence of Félix Ravaisson's "Of Habit."

Using the CRYSTAL17 package at the coupled-perturbed Kohn–Sham (CPKS) level, periodic boundary conditions first-principles calculations are enacted to predict the second harmonic generation second-order nonlinear optical (NLO) susceptibility, χ(2), values of six historical NLO crystals. This selection allowed the comparison between state-of-the-art calculations and experiment. Several computational aspects are tackled to define conditions where the results are converged with respect to the range of lattice summations, to the number of k-points in the first Brillouin zone, to the order of the multipole expansions for evaluating the long-range part of the electrostatic interactions, as well as to the atomic basis set size. A valence triple zeta basis set supplemented with polarization functions has been selected. Then, χ(2) calculations have been performed using a range of exchange-correlation functionals (XCFs). Results show the large impact of the amount of Hartree–Fock (HF) exchange on the amplitude but also on the sign on the χ(2) tensor components. To a given extent, these amplitude effects are consistent with results on molecules, but the sign reversal effects and the non-monotonic behavior of the χ(2) tensor components as a function of the amount of HF exchange are scarcely found for molecules. Then, using the recommended range-separated hybrid XCFs, the CPKS scheme leads to good agreement with experimental data for potassium dihydrogenophosphate, urea, and χ ZXX (2) of LiNbO3. The agreement is more questionable for χ ZZZ (2) of LiNbO3 whereas it remains poor for ammonium dihydrogenophosphate and 2-methyl-4-nitroaniline, with large underestimations by about a factor of 3, opening a path to further fine-tuning of the ranges of inclusion of HF exchange. [ABSTRACT FROM AUTHOR]

The specific features of crystal nucleation widely determine the morphology of the evolving crystalline material. Crystal nucleation is, as a rule, not accessible by direct observation of the nuclei, which develop with time. This limitation is caused by the small size (nanometer scale) of the critical nuclei and the stochastic nature of their formation. We describe an experimental approach to the determination of specific features of the cluster size distribution employing fast scanning calorimetry at scanning rates up to 10 000 K s−1. The surviving cluster fraction is determined by selectively melting/dissolving clusters smaller than the critical size corresponding to the highest temperature of a short spike positioned between the nucleation and the development stage in Tammann's two-stage method. This approach allows for estimating the time evolution of the radius of the largest detectable clusters in the distribution. Knowing this radius as a function of nucleation time allows for determining a radial growth rate. In the example of poly(l-lactic acid) (PLLA), the order of magnitude estimate of radial growth rates of clusters of about 2–5 nm yields values between 10−5 and 10−3 nm s−1. The radial growth rate of micrometer-sized spherulites is available from optical microscopy. The corresponding values are about three orders of magnitude higher than the values for the nanometer-sized clusters. This difference is explainable by stochastic effects, transient features, and the size dependence of the growth processes on the nanometer scale. The experimental and (order of magnitude) classical nucleation theory estimates agree well. [ABSTRACT FROM AUTHOR]

Photochromic diarylethene is known to exhibit reversible photoisomerization under irradiation with ultraviolet (UV) and visible light. Besides reversible optical properties upon light irradiation, a variety of discontinuous morphological changes of the crystals are reported in the literature, such as sudden crystal bending, cracking, and photosalient effects, which are caused simply by UV and visible light irradiation. These morphological phenomena with discontinuities are micro-scale changes caused by photoisomerization of molecules at the nanoscale and lead to the realization of important functions for optical devices. However, the theoretical models behind these phenomena are not well understood. In this paper, we construct a mathematical model that can treat diverse phenomena in a unified model by using swallow-tail catastrophe, a higher-order catastrophe than cusp catastrophe, from the seven elementary catastrophes that can describe discontinuities in the phenomena. By introducing hyperbolic operating curves in the model, the intrinsic properties of the photochromic crystals are represented. The induced morphogenesis, such as bending, cracking, and photosalient effects, are systematically classified by the proposed catastrophe model, which even implies the possibility of unexplored operating conditions of the crystals and explains known phenomena. The proposed catastrophe-theory-based modeling provides a foundation for understanding and discovering the versatile morphogenesis in photochromic crystals. Furthermore, the proposed approach provides a basis for understanding and discovering various morphological changes in photochromic crystals and similar systems. [ABSTRACT FROM AUTHOR]

In this paper, novel nonlocal reformulations of the conventional continuum-based models for modeling the thermoelastic behavior of cubic crystals based on a recently developed lattice particle method are presented. Like molecular dynamics simulation, the lattice particle method decomposes the grain domain into discrete material particles that are regularly packed according to the underlying atomic lattice. Nonlocal interactions are introduced between material particles and top-down approaches are used to relate model parameters to the material physical constants. Three equivalency assumptions are used in the top-down approach, namely, energy equivalency for the mechanical model, heat transfer rate equivalency for the thermal model, and thermal strain equivalency for the thermal-mechanical coupling model. Different from coordinates transformation used in the conventional continuum-based models, lattice rotation is adopted in the lattice particle method to equivalently represent the material anisotropy while explicitly capturing the crystallographic orientation. Two most common Bravais cubic lattices are studied, i.e., the body-centered cubic lattice and the face-center cubic lattice. The validity and prediction accuracy of the developed models are established by comparing the predicted displacements and temperature results with solutions of conventional continuum theories using the finite element method. [ABSTRACT FROM AUTHOR]

Crystallization processes of the solid phase in supersaturated solutions of products of plant origin are used in processing technologies. The theory of diffusion (molecular) mass transfer of the target substance has become widespread when solving problems of technology improvement. The driving force of this process is the difference in the concentration of the solid phase in the solution towards the crystallization center, where the concentration of the solid phase is reduced. During the analytical and quantitative study of the process of solid phase deposition in the crystallization center, Fick's diffusion laws have been used. The influence of solution temperature, concentration of the solid phase, its geometry and dispersed composition on the course of this process have been considered. Based on a diffusion model of the process of crystal formation of sucrose in a vacuum apparatus, a numerical analysis of factors in sugar production technology not covered in the literature has been presented. The problem of quantitative analysis of the process of sucrose crystallization in the working volume of a vacuum apparatus for the production of sugar and other products of plant origin of high commercial standards requires further in-depth study.

We report the growth of bulk β-Ga2O3 crystals based on crystal pulling from a melt using a cold container without employing a precious-metal crucible. Our approach, named oxide crystal growth from cold crucible (OCCC), is a fusion between the skull-melting and Czochralski methods. The absence of an expensive precious-metal crucible makes this a cost-effective crystal growth method, which is a critical factor in the semiconductor industry. An original construction 0.4–0.5 MHz SiC MOSFET transistor generator with power up to 35 kW was used to successfully grow bulk β-Ga2O3 crystals with diameters up to 46 mm. Also, an original diameter control system by generator frequency change was applied. In this preliminary study, the full width at half maximum of the X-ray rocking curve from the obtained β-Ga2O3 crystals with diameters ≤ 46 mm was comparable to those of β-Ga2O3 produced by edge-defined film fed growth. Moreover, as expected, the purity of the obtained crystals was high because only raw material-derived impurities were detected, and contamination from the process, such as insulation and noble metals, was below the detection limit. Our results indicate that the OCCC technique can be used to produce high-purity bulk β-Ga2O3 single crystalline substrate. [ABSTRACT FROM AUTHOR]

Owing to its wide band gap, extreme mechanical hardness and high thermal conductivity, GaN has found widespread applications in optoelectronic devices and high-power/-frequency devices. However, the growth of high-quality and large-size GaN crystal substrates is still a great challenge, which hinders the development of power and radio frequency (RF) devices. The Na-flux method can emerge as an effective strategy to address these challenges. Nevertheless, the growth quality of GaN crystals is influenced by several factors during the growth process. This study focused on investigating the growth rate and quality of GaN in relation to the growth temperature and pressure. It also explains the difference in the solubility between N3− and GaN as a function of temperature in liquid phase melts. The intricacy of the Na-flux method and the opacity of the growth process present significant obstacles to the growth of GaN crystals. In order to accurately determine and optimise the growth conditions, the temperature distribution and material transport during the growth process are predicted by simulation. A series of validation experiments were conducted to investigate the influence of temperature and pressure on GaN crystallisation. Under optimised growth conditions, high-quality GaN crystals with a full width at half maximum of 433 arcsec (002) were obtained. This work provides an effective strategy for the liquid-phase growth of high-quality GaN crystals, facilitating the development of high-performance blue-green lasers, RF and power devices. [ABSTRACT FROM AUTHOR]

By adopting CVD-SiC recycled blocks as a SiC source, SiC crystals were successfully grown with a high growth rate of 1.46 mm h−1via the PVT method. The micropipe density and the dislocation density of the grown crystal suggested good crystal quality despite its high growth rate. [ABSTRACT FROM AUTHOR]

Porous frameworks constructed via noncovalent interactions show wide potential in molecular separation and gas adsorption. However, it remains a major challenge to prepare these materials from low-symmetry molecular building blocks. Herein, we report a facile strategy to fabricate noncovalent porous crystals through modular self-assembly of a low-symmetry helicene racemate. The P and M enantiomers in the racemate first stack into right- and left-handed triangular prisms, respectively, and subsequently the two types of prisms alternatively stack together into a hexagonal network with one-dimensional channels with a diameter of 14.5 Å. Remarkably, the framework reveals high stability upon heating to 275 °C, majorly due to the abundant π-interactions between the complementarily engaged helicene building blocks. Such porous framework can be readily prepared by fast rotary evaporation, and is easy to recycle and repeatedly reform. The refined porous structure and enriched π-conjugation also favor the selective adsorption of a series of small molecules. Porous frameworks constructed via noncovalent interactions show potential in molecular separation and gas adsorption but it is challenging to prepare these materials from low symmetry molecular building blocks. Herein, the authors report a strategy to fabricate noncovalent porous crystals through modular self-assembly. [ABSTRACT FROM AUTHOR]

The Raman spectra of ferrocene crystals were measured at pressures up to 20 GPa, and an abnormally large bandwidth of intermolecular phonons at ambient pressure was found. With an increase in the pressure, the bandwidth increased to a maximum at ~2 GPa and then decreased to a minimum at ~4 GPa, which was equal to the pressure‐independent bandwidth of intramolecular phonons. The unusual behavior of the bandwidth was related to the instability of a ferrocene molecule caused by jumps between its D5d and D5h conformations. A decrease in the time of jumps between the conformations to the period of crystal lattice vibrations led to a loss of coherence and broadening of intermolecular phonon bands. The energy barrier between the conformations was determined to be ~17.6 meV/molecule under ambient conditions and 80 meV/molecule at 4.9 GPa. An increase in the barrier with pressure was due to the enhancement of the crystal field, which resulted in the inhibition of the jumps and the stabilization of the molecule in the D5d conformation. [ABSTRACT FROM AUTHOR]

Manipulating thermal properties of materials can be interpreted as the control of how vibrations of atoms (known as phonons) scatter in a crystal lattice. Compared to a perfect crystal, crystalline solids with defects are expected to have shorter phonon mean free paths caused by point defect scattering, leading to lower lattice thermal conductivities than those without defects. While this is true in many cases, alloying can increase the phonon mean free path in the Cd‐doped AgSnSbSe3 system to increase the lattice thermal conductivity from 0.65 to 1.05 W m−1 K−1 by replacing 18% of the Sb sites with Cd. It is found that the presence of lone pair electrons leads to the off‐centering of cations from the centrosymmetric position of a cubic lattice. X‐ray pair distribution function analysis reveals that this structural distortion is relieved when the electronic configuration of the dopant element cannot produce lone pair electrons. Furthermore, a decrease in the Grüneisen parameter with doping is experimentally confirmed, establishing a relationship between the stereochemical activity of lone pair electrons and the lattice anharmonicity. The observed "harmonic" behavior with doping suggests that lone pair electrons must be preserved to effectively suppress phonon transport in these systems. [ABSTRACT FROM AUTHOR]

2D organic crystals play a unique role in photodetection owing to their tunable detection wavelength, low manufacturing cost, compatibility with lightweight, and controllable synthesis. However, their detection wavelength range mainly encompasses the visible (Vis) and near‐infrared (NIR) spectra. Herein, 2D erucamide crystals are synthesized using nitrogen gas and methanol as raw materials without catalysts at room temperature under atmospheric pressure via laser processing. The synthesized 2D erucamide is demonstrated to be a promising broad bandgap organic semiconductor material. A UV photodetector made of 2D erucamide exhibited a responsivity as high as 145 mA W−1, a millisecond‐level response speed, and an excellent detectivity of 4.96 × 109 Jones. Furthermore, the synthesized erucamide showed an excellent UV–vis suppression ratio (R254 nm/R532 nm) of 59. The synthesis mechanism of erucamide via laser bubbling in liquids is proposed. Thermodynamically, the high temperature of the bubbles is beneficial for nitrogen and methanol decomposition. Kinetically, rapid bubble quenching facilitates final product formation. This accomplishment represented the pioneering utilization of lasers in converting nitrogen gas into organic compounds while introducing 2D erucamide into the realm of organic UV photodetectors. [ABSTRACT FROM AUTHOR]

Organic planar groups have recently been used to construct nonlinear optical materials because of their large hyperpolarizability, and then most of the products have birefringence which is unfavorable to phase matching. Here, a new organic–inorganic hybrid nonlinear optical crystal (C8H6BrN2O)NO3 is synthesized by combining the π‐conjugated organic [C8H6BrN₂O]+ cation and inorganic [NO3]− anion as the fundamental building blocks. Surprisingly, it not only shows a large second‐harmonic generation response of 3.8 times that of the commercial K2HPO4 crystals, but also has a moderate birefringence of 0.08 at 550 nm. Furthermore, it demonstrates high thermal stability up to 220 °C despite its hybrid material characteristics. Single crystal structure analysis and theoretical calculations confirm that the specific arrangement of NLO‐active [C8H6BrN₂O]+ groups with halogen branch chains and strong hydrogen bonding between two π‐conjugated groups leads to moderate birefringence and large frequency‐doubling effect. These findings provide a method to explore hybrid nonlinear optical crystals. [ABSTRACT FROM AUTHOR]

This meta-analysis of 160 semiconductor crystals that were grown in microgravity on orbital vehicles between 1973 and 2016 is based on publicly available information documented in the literature. This analysis provides comparisons of crystal metrics including size, structure quality, uniformity, and improved performance between crystals grown in microgravity or terrestrially. Improvement in at least one of these metrics was observed for 86% of those materials that included data in their studies. [ABSTRACT FROM AUTHOR]

The long-range periodic atomic arrangement or the lack thereof in solids typically dictates the magnitude and temperature dependence of their lattice thermal conductivity (κlat). Compared to crystalline materials, glasses exhibit a much-suppressed κlat across all temperatures as the phonon mean free path reaches parity with the interatomic distances therein. While the occurrence of such glass-like thermal transport in crystalline solids captivates the scientific community with its fundamental inquiry, it also holds the potential for profoundly impacting the field of thermoelectric energy conversion. Therefore, efficient manipulation of thermal transport and comprehension of the microscopic mechanisms dictating phonon scattering in crystalline solids are paramount. As quantized lattice vibrations (i.e., phonons) drive κlat, atomistic insights into the chemical bonding characteristics are crucial to have informed knowledge about their origins. Recently, it has been observed that within the highly symmetric 'averaged' crystal structures, often there are hidden locally asymmetric atomic motifs (within a few Å), which exert far-reaching influence on phonon transport. Phenomena such as local atomic off-centering, atomic rattling or tunneling, liquid-like atomic motion, site splitting, local ordering, etc., which arise within a few Å scales, are generally found to drastically disrupt the passage of heat carrying phonons. Despite their profound implication(s) for phonon dynamics, they are often overlooked by traditional crystallographic techniques. In this review, we provide a brief overview of the fundamental aspects of heat transport and explore the status quo of innately low thermally conductive crystalline solids, wherein the phonon dynamics is majorly governed by local structural phenomena. We also discuss advanced techniques capable of characterizing the crystal structure at the sub-atomic level. Subsequently, we delve into the emergent new ideas with examples linked to local crystal structure and lattice dynamics. While discussing the implications of the local structure for thermal conductivity, we provide the state-of-the-art examples of high-performance thermoelectric materials. Finally, we offer our viewpoint on the experimental and theoretical challenges, potential new paths, and the integration of novel strategies with material synthesis to achieve low κlat and realize high thermoelectric performance in crystalline solids via local structure designing. [ABSTRACT FROM AUTHOR]

Nonlinear optical (NLO) crystals that can expand the spectral range of laser outputs have attracted significant attention for their optoelectronic applications. The research progress from the discovery of new single crystal structures to the realization of final device applications involves many key steps and is very time consuming and challenging. Consequently, exploring efficient design strategies to shorten the research period and accelerate the rational design of novel NLO materials has become imperative to address the pressing demand for advanced materials. The recent shift in paradigm toward exploring new NLO crystals involves significant progress from extensive "trial and error" methodologies to strategic approaches. This review proposes the concept of rational structure design for nonlinear optical crystals leveraging advantageous templates. It further discusses their optical characteristics, promising applications as second-order NLO materials, and the relationship between their structure and performance, and highlights urgent issues that need to be addressed in the field of NLO crystals in the future. The review aims to provide ideas and driving impetus to encourage researchers to achieve new breakthroughs in the next generation of NLO materials. [ABSTRACT FROM AUTHOR]

In this work, we experimentally investigate the potency of high pressure to drive a protein toward an excited state where an inhibitor targeted for this state can bind. Ras proteins are small GTPases cycling between active GTP‐bound and inactive GDP‐bound states. Various states of GTP‐bound Ras in active conformation coexist in solution, amongst them, state 2 which binds to effectors, and state 1, weakly populated at ambient conditions, which has a low affinity for effectors. Zn2+‐cyclen is an allosteric inhibitor of Ras protein, designed to bind specifically to the state 1. In H‐Ras(wt).Mg2+.GppNHp crystals soaked with Zn2+‐cyclen, no binding could be observed, as expected in the state 2 conformation which is the dominant state at ambient pressure. Interestingly, Zn2+‐cyclen binding is observed at 500 MPa pressure, close to the nucleotide, in Ras protein that is driven by pressure to a state 1 conformer. The unknown binding mode of Zn2+‐cyclen to H‐Ras can thus be fully characterized in atomic details. As a more general conjunction from our study, high pressure x‐ray crystallography turns out to be a powerful method to induce transitions allowing drug binding in proteins that are in low‐populated conformations at ambient conditions, enabling the design of specific inhibitors. [ABSTRACT FROM AUTHOR]

To the best of our knowledge, the spectroscopic and highly efficient tunable multi-wavelength laser properties of Er3+,Yb3+,Pr3+ triple-doped BaLaGa3O7 crystals are demonstrated for the first time in this study. The maximum output power of 0.81 W at ∼2.7 μm was obtained under the absorbed pump power of 3.53 W with an optical-to-optical conversion efficiency of 22.9%. The slope efficiency is 27.0%. The results demonstrate that the triple-doped crystals with the sensitizer Yb3+ and deactivator Pr3+ can not only enhance the pump efficiency effectively but also suppress the self-terminating "bottleneck" effect of Er3+ so that the laser threshold is reduced and the laser efficiency is improved. The Er3+,Yb3+,Pr3+ triple-doped BaLaGa3O7 crystal is a promising candidate for high-efficiency mid-infrared laser devices. [ABSTRACT FROM AUTHOR]

We demonstrate the structure, spectroscopy, and laser performance of an Er3+ and Pr3+ co-doped LuYSGG crystal grown by the Cz method. The XRD result shows that it belongs to the cubic system with the space group Ia3¯d. A refractive index curve in the range of 320–3000 nm is obtained by fitting the Sellmeier equation. The lifetimes of the 4I13/2 and 4I11/2 levels are 0.871 and 0.728 ms, and the ratio is reduced obviously from 3.4 to 1.2 due to the doping of deactivator Pr3+. In CW mode, a maximum output power of 1059 mW is achieved with a slope efficiency of 17.58% and laser center wavelength of ∼2.8 μm. Beam quality factors of 1.40/1.34 are achieved. The results suggest that the Er,Pr:LuYSGG crystal is a potential candidate for generating a high-power mid-infrared laser and can be applied in irradiation environments. [ABSTRACT FROM AUTHOR]

Er3+/Yb3+ codoped glass ceramics containing BaF2 crystals were obtained through a melt quenching process; the precipitation of BaF2 nanocrystals was confirmed by structural characterization. The effects of crystal quantity and size on the transmittance and upconversion fluorescence of the samples were analyzed. The precipitation of nanocrystals leads to a significant increase in upconversion luminescence intensity. The fluorescence spectra at different pump powers were measured. Er3+ and Yb3+ energy level diagrams and possible energy transfer routes during upconversion luminescence were explored. Furthermore, the functional relationship between temperature and the upconversion fluorescence intensity ratio of the samples was analyzed. When the temperature is 293 K, the relative sensitivity reaches the maximum of 1.38% K−1. [ABSTRACT FROM AUTHOR]

Isostructural crystals are crucial for the development of high-performance functional materials and precise control over physicochemical properties, whereas the design of isostructural crystals is extremely challenging. In this work single-component isostructural crystals were obtained with the substitution of side-chain groups. High-quality single crystals of isostructural crystals methyl 2-amino-5-methylbenzoate (MAMB) and methyl 2-amino-5-methoxybenzoate (MAMOB) were harvested through sublimation crystallization. Their crystal structures were determined by single-crystal X-ray diffraction (SCXRD). Similar intermolecular interactions and packing modes suggested that MAMB and MAMOB are 3D isostructural, and the quantitative similarity parameters were calculated via the XPac program. Furthermore, these two obtained isostructural crystals exhibited similar blue light emission behaviors and solvation effects. [ABSTRACT FROM AUTHOR]

Manufacturing two‐dimensional (2D) materials or nanosheets with desired crystal faces originating from an established intrinsic 3D structure is a significant challenge. Herein, an intrinsic t3D metal–organic frameworks (MOFs) can be exfoliated into ultrathin metal–organic nanosheets with (001) and (101) crystal faces, which is regulated by the solute's shard and soft acid−base and pH value in the exfoliating solution. The inorganic ligands (with different charges) possessing the similar hardness of Lewis acid‐base of metal center can replace some of the organic ligands along the established crystal faces of the 3D MOFs with different electrostatic potentials, resulting in the exfoliating of the 3D MOFs into metal–organic nanosheets with different crystal faces. Using the Knoevenagel reaction as the catalytic reaction model, the catalytic activity of (001) crystal faces is three times that of (101) crystal faces, which is determined by the different locations of open metal sits in the 3D lamellar structure, further confirming the occurrence of oriented exfoliation. [ABSTRACT FROM AUTHOR]

A method integrating machine learning with first-principles calculations is employed to forecast the formation energy of delafossite crystals, facilitating the rapid identification of stable crystals. This approach identifies several stable candidates and highlights the importance of atomic ionization energy and electron affinity in the formation of delafossite crystals. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) stand out as remarkable materials renowned for their exceptionally high surface area and large number of pores, making them invaluable for diverse sensing applications including gas, biomedical, chemical, and optical sensing. Traditional methods of molecule infusion and release often involve a large number of crystals with varying shapes and sizes, leading to averaged outcomes across a heterogeneous crystal population. In this study, we present continuous monitoring of the infusion and release dynamics of model drug molecules, specifically vitamin B12, within individual Tb-mesoMOF crystals. Our findings underscore the critical influence of crystal size and shape on the infusion and diffusion processes and corresponding color change, underscoring the necessity to account for these factors in the design of large-scale systems. Leveraging optical microscopy, we employed a histogram-based algorithm for image processing, enabling automated tracking of diffusion phenomena. This investigation offers crucial insights into the dynamics of these processes, laying the groundwork for optimizing parameters in future sensing systems. [ABSTRACT FROM AUTHOR]

Molecular crystals that exhibit photomechanical responses show great promise as photoactuators and other smart materials in various fields. Herein, we synthesized two new barbituric acid derivative crystals (crystals 1 and 2), which exhibit distinct photomechanical responses towards a laser irradiation of 532 nm and UV LED photoirradiation of 365 nm, respectively. Crystal 1 demonstrated photomechanical bending upon exposure to 532 nm laser, whereas crystal 2 exhibited dramatic bursting, followed by jumping of its fragments upon UV irradiation. The photomechanical responses of both crystals are attributed to the [2 + 2] photocycloaddition reaction. However, their different kinematic responses are related to different amounts of accumulated strain energy owing to photocycloaddition and its subsequent release in the crystal lattice. The accumulation of strain energy depended on various factors such as the structural arrangement of the crystals, packing modes and overall directionality of non-covalent interactions. Furthermore, the position of the olefinic bond and peripheral substituents played a key role in determining the development of strain energy. [ABSTRACT FROM AUTHOR]

Upon melting, the molecules in a crystal explore numerous configurations, reflecting an increase in disorder. The molar entropy of disorder can be defined by Boltzmann’s formula ΔSd = Rln(Wd), where Wd is the increase in the number of microscopic states, so far inaccessible experimentally. We found that the Arrhenius frequency factor A of the electron diffraction signal decay provides Wd through an experimental equation A = AINTWd, where AINT is an inelastic scattering cross section. The method connects Clausius and Boltzmann experimentally and supplements the Clausius approach, being applicable to a femtogram quantity of thermally unstable and biomolecular crystals. The data also showed that crystal disordering and crystallization of melt are reciprocal, both governed by the entropy change but manifesting in opposite directions. [ABSTRACT FROM AUTHOR]

By electric fields-based crystal polymorphism recognization, Form I, form II, and form IV INA crystals are screened and prepared with high success rate (>95%) under different electric fields. Massive preparation of high polymorphic purity INA crystal (>98.4%) is achieved through magnifying confined liquid volume by 5000 times from 1.0 μL to 5.0 mL. Meanwhile, 2 to 3 cm single crystal (form II) could be prepared with high throughput. [Display omitted] Active pharmaceutical ingredients (APIs) crystal preparation is a significant issue for the pharmaceutical development attributed to the effect on anti-inflammatory, anti-bacteria, and anti-viral, etc. While, the massive preparation of API crystal with high polymorphism selectivity is still a pendent challenge. Here, we firstly proposed a criterion according to the molecular aggregation, molecular orientation, and hydrogen bond energy between INA molecules from molecular dynamics (MD) simulations, which predicted the hydrogen bond architecture in crystal under different electric fields, hinting the recognition of crystal polymorphism. Then, an electric field governing confined liquid crystallization was constructed to achieve the INA crystal polymorphism screening relying on the criterion. Further, magnifying confined liquid volume by 5000 times from 1.0 μL to 5.0 mL realized the massive preparation of INA crystal with high polymorphic purity (>98.4%), giving a unique pathway for crystal engineering and pharmaceutical industry on the development of innovative and generic API based drugs. [ABSTRACT FROM AUTHOR]