Новые публикации

https://doi.org/10.1002/andp.202500089

The enhancement of surface plasmon polariton (SPP) gain and propagation length at optical frequencies on the interface between a metal film and a medium with Raman gain, in the presence of a coherent control field, is theoretically investigated. It is shown that the Raman interaction between the SPP excitation field and the control field can provide gain sufficient for lossless SPP propagation. This interaction reduces the requirement for the SPP excitation field. It is shown that a significant increase of the propagation length can be achieved in the case of lossy propagation. By varying the intensity or frequency of the control field it is possible to control the SPP. Optical control of the dynamics of SPP propagation by means of an external coherent field in the Raman interaction process holds promise for quantum control in the field of photonics.

DOI: 10.1063/5.0257482

The permittivity tensor of gold nanofilms of different orientations and thicknesses in the frequency range of 0-6 eV is theoretically studied, revealing significant differences from the bulk gold permittivity. Two models are proposed to calculate the longitudinal ɛ‖(h, ω) and transverse ɛ⊥(h, ω) parts of the permittivity tensor in the specified frequency range for gold nanofilms of different thicknesses and surface orientations (001), (110), and (111). These models explain intense peaks in the real and imaginary parts of permittivity at 0-2 eV. The model for calculating the transverse permittivity does not use the Drude model but uses the interband contribution of the bulk material determined through DFT calculations and the contribution of electron motion perpendicular to the nanoslab surface. This contribution takes into account the electron motion inside an infinitely deep one-dimensional potential well with a set of discrete electron levels and makes it possible to calculate the imaginary part of the permittivity using Fermi's golden rule. The model for calculating the longitudinal permittivity employs an interpolation scheme using the tabulated permittivity of bulk gold and that of several plates with different thicknesses. The difference between experimental permittivity values and those calculated using DFT and the proposed models is discussed. The proposed algorithms enabled a Python program for fast calculation of ɛ⊥(h, ω) and ɛ‖(h, ω) of gold nanofilms of any thickness and above-mentioned orientations in the 0-6 eV range without computationally expensive DFT calculations. This program is included in the supplementary material. The proposed approaches can be easily applied to nanofilms made of other metals.

Physical Review B, 111(21), art. no. 214507

https://doi.org/10.1016/j.vacuum.2025.114452

The authors regret the omission of supplementary information file in the aforementioned article. We hereby add the missing text file describing the experiment and calculation details.

https://doi.org/10.1134/S1062873825710906

The spectral properties of a one-dimensional phononic crystal bounded by a reflector in the form of an air layer are studied. A defect in a phononic crystal with a reflector at the edge results in coupling between the detect mode and acoustic Tamm state. This coupling between modes of different natures manifests as the hybridization of modes, and the repulsion of dips in the reflectance spectrum is explained by avoided crossing of the modes.

https://doi.org/10.1134/S0040577925050083

Based on the atomic representation for spin operators in the case of an arbitrary value of the spin �, we study the influence of quantum fluctuations on spin-wave renormalizations of the Néel temperature �N and on the magnetization of quasi-two-dimensional triangular-lattice antiferromagnet sublattices. The application of combined Green’s functions constructed using spin operators and their partial components allows easily obtaining a closed system of equations determining not only all branches of the spectrum of collective excitations but also the occupation numbers of states of an atom with different values of the spin projection. We show that the renormalization of �N is expressed in terms of the generalized Watson integral. Its nontrivial dependence on the degree of quasi-two-dimensionality and on the dynamical properties of three spectral branches determines the behavior of the critical temperature in the cases of different relations between the parameters of the quasi-two-dimensional antiferromagnet.

https://doi.org/10.26907/mrsej-24301

Temperature-dependence measurements specific heat, thermoelectric power, conductivity, and electron paramagnetic resonance measurements were performed on Mn_0.75Co_2.25BO₅ powder at temperatures above 290 K. Single crystals of Mn_0.75Co_2.25BO₅ were grown by the flux method using Bi₂Mo₃O₁₂-based solvent diluted with Na₂CO₃. To investigate EPR and specific heat capacity, the single crystals were ground to powder. The temperature dependencies of the resistance, specific heat, Seebeck constant, and EPR spectra in the range from 290K to 700K were obtained. The transition from the dielectric state to the semiconductor state was detected at 348 K, consistent with the change in the fine structure of the EPR spectrum associated with S = 5/2 for the manganese ion Mn²⁺.

https://doi.org/10.1039/D5TC00678C

Far-red (FR) light is involved in plant photomorphogenesis as a light signal. To realize the match between the absorption peak (730 nm) of a plant photosensitive pigment (Pfr) and the emission spectrum (708 nm) of a Y₃Ga_4.87O₁₂:0.13Cr³⁺ (YGO:0.13Cr³⁺) phosphor, in this study, we employed an ‘A site modification-B site response’ crystal-field-modulation strategy using the garnet structure Y₃Ga₅O₁₂, where doping large radius Gd³⁺ at the A site induced [YO₈] polyhedral expansion and triggered [GaO₆] octahedral distortion, thereby weakening the crystal field strength to achieve a red shift in the spectrum. The optimized Gd_1.2Y_1.8Ga_4.87O₁₂:0.13Cr³⁺ (GYGO:0.13Cr³⁺) phosphor exhibited high external quantum efficiency (34%) and excellent thermal stability (85.5% intensity at 423 K) under 450 nm excitation. Its emission peak at 726 nm was significantly close to 730 nm, while its luminescence intensity was improved by 141% that of the original system. It was successfully fabricated as an FR pc-LED device, achieving a 36.86 mW output power and 13.5% photoelectric efficiency at 100 mA current. Lettuce growth experiments showed that the device enhanced biomass production by 30% through precise spectral adaptation. The present work can promote the leap in plant lighting from rough supplementation to spectral customization through the whole chain of structural aberration–photoelectricity–biological effects.

DOI: https://doi.org/10.1103/PhysRevB.111.195150

In the intermetallic rare-earth tetragonal EuAl4 system, competing itinerant exchange mechanisms lead to a complex magnetic phase diagram, featuring a centrosymmetric skyrmion lattice. Previous inelastic x-ray scattering (IXS) experiments revealed that the incommensurate charge-density wave (CDW) transition in EuAl4 (𝑇CDW=142K) is driven by momentum-dependent electron-phonon coupling (EPC). We present the results of IXS under high hydrostatic pressure induced by diamond anvils and show how the EPC in EuAl4 is renormalized and suppressed in the material's temperature-pressure phase diagram. Our findings highlight the crucial role of momentum-dependent EPC in the formation of the CDW in EuAl4 and provide further insights into how external pressure can be used to tune charge ordering in quantum materials.

https://doi.org/10.1016/j.fmre.2025.02.007

Trivalent lanthanide Ce(III) with a typical allowed 4f – 5d transition generally exhibits short decay time in a nanosecond level, beneficial to fast X-ray imaging applications. Herein, we rationally design and synthesize two zero-dimensional Ce³⁺ based halide hybrids, namely [Emim]₃CeBr₆ and [Emmim]₃CeBr₆ (Emim = 1-ethyl-3-methylimidazolium; Emmim = 1-ethyl-2,3-dimethylimidazolium), both exhibiting intense broad-band violet-to-blue emission originated from Ce³⁺ with near-unity photoluminescence quantum yield. The short nanosecond decay time and the heavy atom effect further inspire us to explore their X-ray scintillation performance. Up to 48,000 photons MeV^-1 light yield is derived together with the low detection limit (around 626 nGy s^-1), and thus a composite film is fabricated to achieve dynamic fast X-ray imaging. This study enlarges the family of scintillators in Ce(III)-based halide hybrid with short decay time.

https://doi.org/10.1016/j.jre.2024.06.022

Er³⁺- and Tm³⁺-doped Ca_xSr_2‒xNb₂O₇ (C_xS_2‒xN, x = 0.6, 0.8, 1.0, 1.2, 1.4) phosphors with layered perovskite structure were designed. These phosphors exhibit a dominant emission peak at 549 nm under 980 nm laser excitation, attributed to the ⁴S_3/2 → ⁴I_15/2 transition. By increasing the content of Ca²⁺, the crystal field regulation of rare earth ions is realized and the luminescence enhancement is induced, which is manifested by the increase of ²H_11/2,⁴S_3/2 → ⁴I_15/2 emission. Furthermore, the temperature sensing sensitivities of C_0.6S_1.4N:Er,Tm and C_0.6S_1.4N:Er,Tm based on non-thermally coupled energy levels were studied. Finally, an anti-counterfeiting imprint was prepared using phosphors, which have high brightness and excellent photothermal stability. This work not only confirms that closer ionic radii substitution enables to increase the electronic density of states, improve the crystal field symmetry and enhance the luminescence, but also provides a promising phosphor system for temperature sensing and anti-counterfeiting applications, opening up new prospects in the optimization of the optical properties of phosphors.

https://doi.org/10.1016/j.jallcom.2025.181052

Fe³⁺ activator is a NIR candidate due to its non-toxicity and low cost. Herein, a NIR phosphor BaZnAl₁₀O₁₇: Fe³⁺ (BZA: Fe³⁺) with high external quantum efficiency (EQE = 54.1 %) and excellent thermal stability is synthesized. Various emission spectra can be observed under three different excitation wavelengths, which is attributed to the occupation of Fe³⁺ on two octahedral sites and a tetrahedral site. The anti-thermal quenching phenomenon under the excitation wavelength of 340 nm can be attributed to trap-assisted energy compensation, weak electron-phonon coupling and energy transfer between different Fe³⁺ sites. These sparkling properties indicate application potential in the field of plant lighting.

https://doi.org/10.1016/j.vacuum.2025.114398

High-vacuum carbosilicothermic reduction of MnO_x thin films on Si(100) substrates was investigated in the temperature range of 200–700 °C using in-situ Auger electron spectroscopy along with mass spectroscopy and ex-situ X-ray photoelectron spectroscopy. Carbothermic reduction of manganese, accompanied by the CO evolution, occurs over the entire temperature range. When heated above 500 °C, silicothermic reduction and formation of manganese silicides are observed. The efficiency of carbothermic reduction of Mn in thin films turned out to be higher at C:Mn = 1:10 than at C:Mn = 1:5. Carbon in the samples is assumed to be present in two forms: as amorphous carbon in a mixture with oxygen and manganese, and as individual, larger particles with a graphite structure. The particle size depends on the power of the magnetron source and influences the carbon coalescence activity, which competes with the carbothermic reduction process. The efficiency of silicothermic reduction on the film surface depends on the initial carbon concentration.

https://doi.org/10.1016/j.optmat.2025.117150

Polarized absorption spectra of the Ho_0.75Nd_0.25Fe₃(BO₃)₄ crystal in the region of ⁵I₈→⁵F₅, ⁵S₂ + ⁵F₄, ⁵F₃ and ⁵F₂ absorption bands of Ho ions were studied as a function of temperature in the range of 5–20 K. The absorption spectra were decomposed into Lorentzian or Gaussian components. Below 203 K, the local symmetry of the holmium ion is C₂. However, an analysis of the polarization of the absorption lines from the point of view of the selection rules showed that in the easy-axis state of the crystal (T < T_R = 6.9 K), the local symmetry of the holmium ion is close to D₃. At T > T_R, a distortion of the local symmetry appears, which increases with increasing temperature. Shifts in the positions of absorption lines are observed at the spin-reorientation transition. The shifts are different for different lines. This means that the local magnetic anisotropy of the holmium ion, the Ho–Fe exchange energy, and the local crystal field are different in different excited states of holmium. Significant and different changes in the intensity of absorption lines depending on temperature were observed both during the reorientation transition and above it, which is a consequence of changes of the local crystal field in excited states with temperature.

https://doi.org/10.1007/s11182-025-03448-6

The phase transformations, taking place in α−Fe₂O₃ during its mechanical grinding in an AGO-2C planetary ball mill with an aim to manufacture a Fe₃O₄-based magnetic powder, are studied. The grinding is performed using steel vials and balls under different modes, grinding times (up to 120 min), mill rotation frequencies (1290, 1820, 2220 rpm), processing media (water, isopropyl alcohol, dry grinding in air), degree of filling vials with balls and powder (from 1/12 to 2/3 of vial volume), and ball-to-powder mass ratios (from 2.5:1 to 20:1). It is shown that different grinding modes strongly affect the−Fe₂O₃→Fe₃O₄ phase transition, resulting in different phase concentration ratios in the milled powder. It is noted that the magnetite concentration increases with the grinding energy density, which depends on the rotation frequency and grinding time. The most effective modes of the Fe₃O₄-based nanostructured powder manufacture are established, which involve the maximum rotation frequency, the grinding time up to 120 min, and the ball-to-powder ratio 10:1. The magnetic powder thus produced has the Curie temperature of 556 °C and the saturation magnetization of 65 emu/g.

DOI:10.21046/2070-7401-2025-22-2-154-162

https://doi.org/10.1016/j.matlet.2025.138728

The effect of cyclic loading/unloading on high-temperature superelasticity and the (B2 + γ/γ’)-microstructure was studied in quenched Co₃₅Ni₃₅Al₂₈Fe₂ single crystals oriented along the [001]_B2-direction. They displayed excellent superelastic response in compression over 100 loading/unloading cycles at 423 K. This superelasticity response is attributed to the high-strength crystallographic [001]_B2 orientation of the B2-matrix and strengthening of the γ-phase due to nanosized γ’-particles. The stress-induced B2-L1₀ martensitic transformation during loading/unloading cycles was accompanied by plastic deformation via twinning of the secondary γ/γ’-phase and dislocation accumulations in B2-matrix around the γ/γ’-phase. This results in a reduction in the critical stress for the martensite formation, stress hysteresis and reversible strain during cycling.

https://doi.org/10.48550/arXiv.2503.03246

We use time-dependent density functional theory-based approaches, TD-DFT and TD-DFTB, to investigate the optical absorption of B800 part of Rhodoblastus acidophilus light-harvesting complex 2 (LH2). Both methods are shown to give qualitative agreement with experimental spectra for a single BChl a molecule and for the optimized structure of B800 complex containing nine of such molecules. We proved the absence of any sizable effects originating from the interaction between adjacent molecules, thus optical features of B800 LH2 part should not be attributed to the structural organization of pigments. In addition, time-dependent procedure itself was found to be crucial for the correct description of BChl a absorption spectrum.

https://doi.org/10.1134/S1063784225700057

Using electrodynamic analysis of the 3D model of a plane-parallel ideal dielectric plate, the propagation of plane linearly polarized electromagnetic waves is investigated in the case when their angle of incidence φ deviates from the normal to the plane of the plate. It is found that in the case of parallel polarization, when the electric field vector lies in the plane of incidence and magnetic field vector is parallel to the plane of plate, the Q factor of the observed half-wave resonance first decreases to its minimal value with increasing φ as the Brewster angle is approached, and then increases, tending to infinity as φ → 90°. In the case of perpendicular polarization, when the magnetic field vector lies in the plane of incidence and the electric field vector is parallel to the plane of the plate, the Q factor of the half-wave resonance gradually increases with increasing φ, also tending to infinity as φ → 90°. However, the dependences of the observed monotonic increase in the resonance frequencies with the angle of incidence are identical for both polarizations. The results of experiment with a plane-parallel plate made of ultrahigh molecular weight polyethylene with a dielectric constant of 2.5, which has been performed using broadband horn antennas, are in good agreement with the results of the electrodynamic calculation based on the 3D model.

https://doi.org/10.1016/j.jallcom.2025.180642

Since catalytically active materials require special synthesis conditions, which cause difficulty in scaling, it is necessary to develop new lightweight scalable approaches for industrial applications. The most obvious way is to use elementary components to fabricate complex structures. In our work, we used a fundamental ampoule synthesis method to produce MSSe (M = Mo, W) powders with a homogeneous random distribution of chalcogen atoms. The synthesized samples exhibit P6₃/mmc space group indicating the existence of 2 H phase which was proved by comprehensive experimental and theoretical analysis and demonstrates rational characteristics in the hydrogen evolution reaction. The Tafel slopes for synthesized MoSSe and WSSe are 93 and 86 mV/dec, respectively. Moreover, the MSSe samples demonstrate the same catalytic activity in the hydrogen evolution reaction as the samples subjected to ultrasonic treatment in N-Methyl-2-pyrrolidone, with Tafel slopes of 92 and 88 mV/dec for MoSSe and WSSe, respectively.

https://doi.org/10.1016/j.optlastec.2025.113012

The spectral and polarisation characteristics of a Fabry–Pérot cavity filled with photo-controlled chiral nematic are investigated. The chiral nematic under planar-tangential boundary conditions is used, enabling the structure to change in the twist angle continuously under the action of the controlling blue or UV light. An increase in the structure twist angle leads to a rise in the geometric phase of the eigenmodes accompanied by a red spectral shift of ��-modes and a blue spectral shift of ��-modes. The spectral shift of the modes is studied experimentally, through numerical simulation and by analytical treatment. A generalised resonance diagram of the chiral nematic cavity is obtained. Measurements of the geometric phase values as a function of the structure twist angle are made. The proposed chiral nematic cavity with a variable geometric phase can be promising to develop photonic devices with photo-controlled features.

Ferrites are a type of magnetic oxide that have garnered a lot of attention due to their versatile properties and numerous applications in various technological domains. The morphological and structural aspects of ferrites are explained in this chapter, with special attention to the finer points of their crystallography and surface features. The atomic and nanoscale structural configurations that are inherent to matter through analytical techniques such as spectroscopy, electron microscopy, and X-ray diffraction (XRD) are discussed. The first section of the chapter examines the crystallography of ferrites, outlining their different crystal forms and phases, including the ubiquitous spinel structure and hexagonal phases. Extensive investigation of XRD patterns provide insight into lattice properties, crystal symmetry, and phase purity. Techniques including transmission electron microscopy (TEM), atomic force microscopy (AFM), and scanning electron microscopy (SEM) used to examine the surface characteristics, particle size distribution, and agglomeration tendencies are described. We also discuss how the synthesis setting affects the morphological features, which sheds light on the specifics of ferrite creation. In addition to catalysis, the chapter also demonstrates the role of ferrite morphology in a range of applications, including electronics, biomedical, and environmental remediation. The relationship between structural-morphological properties offers insights that could help improve the development and application of ferrite-based materials. The knowledge gained from this chapter should spur advancements in the design, production, and application of ferrite in numerous industries, resulting in advances in electronics, magnetic materials, catalysis, and other domains.

DOI:10.18083/LCAppl.2025.1.52

https://doi.org/10.1364/JOSAA.546862

The scattering problem for anisotropic layered systems is solved by modification of Rumpf’s scattering matrix method [Prog. Electromagn. Res B 35, 241 (2011)
Crossref   ; “Computational electromagnetics. Topic 2” (2024)]. The modified method allows one to calculate the scattering coefficients as well as the electromagnetic field distribution along the layered structure. The method is verified in application to the scattering problem for a cholesteric liquid crystal layer, a magneto-optic structure, a photonic crystal covered by metal, and a slab made of left-handed material.

DOI 10.1088/1361-6668/adc8dd

To study the thermodynamic properties of the disorder-induced transition between �± and �++ superconducting gap functions, we calculate the grand thermodynamic potential Ω in the normal and the superconducting states. An expression for the difference between the two, ΔΩ, is derived for a two-band model for Fe-based systems with nonmagnetic impurities. The disorder is considered in a �-matrix approximation within the multiband Eliashberg theory. In the vicinity of the Born limit near the �±-to-�++ transition, we find two solutions obtained for opposite directions of the system's evolution with respect to the impurity scattering rate. By calculating the change in entropy ΔS and the change in the electronic specific heat ΔC from ΔΩ, we show that such a hysteresis is not due to the time-reversal symmetry breaking state, but that it instead points to the first order phase transition (PT) induced by the nonmagnetic disorder. Based on the ΔΩ calculations, a phase diagram is plotted representing the energetically favorable �± and �++ states and the transition between them. At finite temperature, a first order PT line there is limited by a critical end point. Above that point, the sharp �±→�++ transition transforms into a crossover between �± and �++ states.

https://doi.org/10.1007/s11144-025-02852-w

In this work, spray-dried poly(3-hydroxybutyrate-co-3-hydroxyvalerate) microparticles (P(3HB-co-3HV) MPs) containing conventional antibacterial drug rifampicin (RIF), as well as novel cytostatic ozonide (OZ) were obtained and characterized. The effect of drug chemical structure on its encapsulation and release profile, as well as MPs characteristics (mean size, polydispersity index, zeta potential) was investigated. The obtained RIF-MPs and OZ-MPs revealed the mean diameter of 3.14 ± 0.08 μm and 1.94 ± 0.05 μm, respectively, spherical shape, smooth surface and uniform size distribution. The release of RIF and OZ from the P(3HB-co-3HV) microparticulate matrix had a two-stage pattern with the burst effect and followed the Fickian diffusion-controlled mechanism.

https://doi.org/10.1016/j.materresbull.2025.113485

New noncentrosymmetric molybdate Tm₂Zr(MoO₄)₅ was synthesized. The crystal structure variation with temperature was determined by Rietveld analysis. At 303 K, the monoclinic structure was determined in space group P2₁. A reversible phase transition P2₁↔Cmc2₁ was found at 390 K. From 423 to 520 K, nearly a ZTE (α = 0.7 × 10⁻⁶ K⁻¹) behavior was revealed. In the range of 520–720 K, the negative thermal expansion (NTE) effect (α = -2.3 × 10⁻⁶ K⁻¹) is evident for the cell volume. Tm₂Zr(MoO₄)₅ is stable up to 1100 K. Electronic structures of monoclinic and orthorhombic Tm₂Zr(MoO₄)₅ were evaluated by DFT methods. The bandgap values determined for monoclinic Tm₂Zr(MoO₄)₅ are E_{g direct} = 3.83 eV and E_{g indirect} = 3.43 eV. The vibrational properties of monoclinic phase were characterized by Raman spectroscopy. The photoluminescence emission in monoclinic Tm₂Zr(MoO₄)₅ at 303 K is dominated by a narrower band at 650 nm due to the ¹G₄ - ³F₄ transition.

https://doi.org/10.1016/j.ceramint.2025.04.041

In this study, lanthanum (La) modified 0.85(0.9Na_0.5Bi_0.5TiO₃–0.1Na_0.8Sr_0.1NbO₃) −0.15Sr_0.85Er_0.1TiO₃ ceramics, abbreviated as (NBT–NSN)–SET–xLa, ceramics were synthesised. The best 0.020 La ceramic specimens were selected and improved by viscous polymer processing (VPP) to further enhance their energy storage densities. It ultimately reached a high breakdown field strength of 460 kV/cm, at which the recoverable energy density and efficiency of 6.87 J/cm³ and 74.7 % were attained. At present, although many studies on La doping have shown that La elements can effectively refine grains, thereby increasing electrical breakdown strength and ultimately improving energy storage performance. However, there is no clear explanation at the mechanism layer. In this article we try to make this clearer in terms of structural evolution and modelling. We use XRD and Raman spectroscopy to elucidate the effect of La doping on structural evolution and explain the relationship between structure and properties. In addition, this study combined with comsol software to simulate the electrical breakdown process after La doping, which can help readers to fully understand the mechanism and lay a theoretical foundation for future industrial applications.

https://doi.org/10.1080/1536383X.2025.2485241

Our present study aims to obtain and examine the fullerenols (water-soluble derivatives of fullerenes) with various amounts of hydroxyl groups. The work presents the results of obtaining fullerenols by boiling in nitric acid with subsequent hydrolysis of polynitro intermediates with water at different treatment durations. The obtained samples were certified by X-ray photoelectron and IR spectroscopy methods and it was found that 10-h treatment allowed obtaining fullerenol with the composition C₆₀O_x(OH)_y, where x + y = 12−14, 15-h treatment yielded C₆₀O_x(OH)_y, where x + y = 16−18, and 20-h boiling in acid yielded C₆₀O_x(OH)_y, where x + y = 24−26. The reproducibility of the obtained results allowed the addition of a predictable number of functional groups.

https://doi.org/10.48550/arXiv.2502.01483

The dependence of the energies and orbital structure of local states in the CuO monolayer on intra- and interatomic Coulomb interactions on copper and oxygen orbitals is studied. The electronic system is described within the eight-band p-d model in the hole representation with the on-site energies and hopping integrals obtained using density functional theory. CuO cluster multiparticle eigenstates are calculated using exact diagonalization. The difference between the energy dependencies on the Coulomb parameters for the states with the predominant probability density on the d-orbital and the states in which hole occupies p-orbitals leads to crossover of d- and p-states. The ground single-hole and two-hole states which determine the electronic structure of the low-energy excitations have the character of d- or p-orbitals in the different regions of the Coulomb parameters space. The gap between the energies of the dispersionless quasiparticles forming the top of the valence band and conductivity band also have different values in these two regions. The magnitude of this gap and the orbital character of the local multiparticle states change sharply even with an insignificant change in the Coulomb interactions within the boundary region of parameters between the regions in which the local states are formed by the d- or p-orbitals.