250 results about "Electron energy" patented technology

The invention discloses a method for exploring a heterogeneous catalytic reaction network based on a deep potential energy surface model, and the method comprises the steps: carrying out the accurate prediction of the free energy change of all possible element reactions on a catalyst through the combination of transfer learning and a density functional theory, and constructing a reaction network diagram based on a graph theory method; an improved Dijkstra method is used for searching a reaction network diagram to determine a reaction mechanism, and the selectivity of the catalyst is explored based on a Markov chain method. According to the technical scheme provided by the invention, when the CO2 reduction reaction mechanism on the monatomic alloy is explored, the prediction error MAE of the electron energy of each intermediate is only 0.16 eV, the calculated amount is reduced by 90%, the dominant path of the CO2 reduction reaction is visually displayed, and a new normal form is provided for complex mechanism exploration and catalyst screening.

The invention relates to the technical field of electron energy measurement, and discloses an electron spectrometer and an electron energy spectrum measurement method and system.The electron spectrometer comprises a magnetic deflection unit used for receiving an incident to-be-measured electron beam, generating a magnetic field and applying the magnetic field to all to-be-measured electrons in the to-be-measured electron beam; the scintillator fluorescent screen is arranged at the downstream of the magnetic deflection unit and used for receiving the deflected electrons to be detected, and the electrons bombard the scintillator fluorescent screen and generate light spots; the optical acquisition unit is used for acquiring a light spot image on the scintillator fluorescent screen; and the signal processing unit is used for processing the light spot image so as to identify the spatial position information of the light spot in the light spot image and convert the spatial position information into electronic energy data. The method has the beneficial effects that the unification of high resolution and high measurement efficiency is realized, and the problem of signal accumulation under a high counting rate of a traditional direct measurement method and the inherent defect of low efficiency of a scanning type magnetic spectrometer are overcome.

The invention belongs to the technical field of organic dye synthesis and application, and discloses a conjugated compound containing a benzothiophenazine structure as well as a preparation method and application thereof, and the conjugated compound containing the benzothiophenazine structure has excellent photophysical properties, singlet oxygen yield and superoxide anion generation capacity. The novel conjugated compounds ENBO-NI and ENBS-NI containing benzothiophenazine structures are successfully prepared by replacing a benzene ring of Nile blue with a cycloalkane structure and adjusting the electron donating ability of an R1 group. The two compounds have near infrared fluorescence emission, good solubility and relatively high ROS yield. Compared with a classical photosensitizer NB, the singlet oxygen yield of ENBO-NI is increased by about 117.65%, and the singlet oxygen yield of ENBS-NI is as high as 70%. The absorption wavelength of the conjugated compound is in a red light wave band. The preparation process is simple and efficient, large-scale production is easy, and the preparation method has a wide clinical application prospect.

The utility model relates to a diagnostic imaging system and a radiation detector thereof. The radiation detector comprises an anode assembly, a cathode assembly, a conversion assembly and an irradiation assembly. In the diagnostic imaging system, radiation penetrates through the cathode assembly and reaches the conversion assembly, visible light and / or infrared light are / is emitted through the irradiation assembly to irradiate the conversion assembly, so that the radiation can be converted into electrons and holes in the conversion assembly, the electrons can be collected by the anode assembly, and the electrons are collected through the anode assembly. Therefore, the number change of electrons can be detected at the contact position of the signal generator and the anode assembly, the electrons can be converted into radiation site signals, radiation penetrating through a to-be-imaged object is detected, the transparent electrode is transparent to infrared light and / or visible light, the photoinduced quantum yield is increased, and the imaging quality is improved. The above effects improve the stability of the radiation detector in a radiation use environment.

The invention discloses a compound and a preparation method thereof and an electronic device, the molecular structure general formula of the compound is shown in the specification, R is selected from one of the following structures, X1-X2 are respectively and independently selected from one of oxygen atoms, sulfur atoms, selenium atoms and nitrogen atoms, and X is a positive integer. X < 3 > to X < 4 > are respectively and independently selected from one of the following structures; and X < 5 > to X < 6 > are respectively and independently selected from any one of alkyl groups. According to the compound provided by the invention, the electron pushing and pulling capability in the compound is adjusted by changing the structures of a donor and an acceptor, so that the purpose of regulating and controlling molecular electron cloud distribution and energy level is achieved, and key physical properties such as emission wavelength, radiative transition rate (kr) and backlash crossing rate (kRISC) of a material are systematically regulated and controlled. The compound as a guest material of a luminescent layer has good comprehensive performance when being applied to organic electroluminescent devices for solution processing and vacuum evaporation.

The invention provides a Se anion-doped ferric phosphate pyrophosphate / carbon positive electrode active material and a preparation method and application thereof, and relates to the technical field of electrochemical energy storage device positive electrode active materials, the positive electrode active material comprises a ferric phosphate pyrophosphate base material and a carbon coating layer, in the crystal structure of the base material, part of O is partially replaced by Se, and the general formula of the base material is Na4Fe3 (PO4) 2 (P2O7-xSex), x is less than or equal to 1.0; o < 2-> is partially replaced by Se < 2-> in a crystal structure of a matrix material to construct a Se-doped solid solution, so that an electron energy band structure of the material is regulated and controlled; due to introduction of Se, the band gap of the material can be remarkably reduced, the electron conductivity can be improved, local lattice distortion can be caused, a Na < + > diffusion channel can be widened, and the ion migration capability can be improved; the material keeps a complete main phase structure, electron and ion transmission is synergistically optimized, and the rate capability is remarkably improved.

The invention relates to the technical field of polymer synthesis, in particular to a dynamic response type polymer with aggregation-induced emission characteristics and a preparation method and application thereof. The dynamic response type polymer is formed by polymerizing raw materials including a compound containing a diphenylmethane structure and a derivative thereof and a sulfur-containing side chain or a directly connected sulfur-containing group compound. The dynamic response type polymer disclosed by the invention realizes a dynamic luminescence process, and solves the problems that the original AIE polymer is simple in luminescence process, low in information encryption degree and unobvious in environmental response signal; the total visible light emission can be conveniently and accurately adjusted by changing the electron supply and absorption capacity of the core group structure, the real-time emission adjustment capacity of the same material is achieved, industrial-grade raw materials and a mature synthesis process are adopted, the cost is low, synthesis is convenient, and the 4D dynamic anti-counterfeiting encryption material has wide application prospects in the field of 4D dynamic anti-counterfeiting encryption.

The application discloses a method for producing formaldehyde at low temperature, and belongs to the technical field of formaldehyde production. The method comprises the following steps: preparing a high-efficiency catalyst by taking iron nitrate nonahydrate, ammonium molybdate tetrahydrate and lithium hydride as raw materials; feeding mixed gas of methanol and air into a reactor filled with the high-efficiency catalyst under the condition that the temperature is 250-280 DEG C; and collecting gas at the outlet of the reactor to complete the method for producing formaldehyde at low temperature. The embedding of lithium can expand the crystal lattices of the catalytic products, thereby generating a large number of oxygen vacancies, enhancing the electron-donating capacity, and enabling the adsorption of p-formaldehyde to be quickly dissociated and the active sites to be quickly reduced at a relatively low temperature, so that the activity of subsequent catalysis is ensured. The plasma treatment can increase the surface area and the number of active sites of the high-efficiency catalyst, and further improve the catalytic activity. The method for producing formaldehyde at low temperature can improve the conversion rate of methanol and the yield of formaldehyde at a relatively low temperature, and is helpful to reduce energy consumption and reduce the volatilization of Mo.

The application discloses a pressure sensor based on friction nanogenerator, which can be deployed in a wearable device for monitoring pulse fluctuation, or deployed in an electronic device with a touch screen for detecting touch action. The sensor comprises two friction layers and at least one electrode layer. The two friction layers are respectively made of materials with different electron loss and gain abilities. The surface of at least one friction layer comprises a multi-stage micro-nano structure for inducing equal and opposite net charges corresponding to the applied pressure on the two friction layers under pressure. The multi-stage micro-nano structure comprises at least two kinds of micro-nano columnar structures with different heights. The electrode layer is used for generating current based on the net charges. The application can make the pressure sensor maintain high sensitivity to large static force through the designed multi-stage structure with different heights, and can expand the measurement range of the pressure sensor, so that the sensor maintains the same or similar sensitivity under various static forces.

The application discloses a method for realizing ionosphere aircraft stealth based on regulating and controlling electron distribution of tail area, first, evolution time scales under different non-extended parameters are calculated; and according to the superhot electron energy and particle flux per unit time required by different non-extended parameters, a radio frequency discharge plasma generator is controlled to generate plasma corresponding to the non-extended parameters; then, in the grid electric field, electrons enter the acceleration field area, and ions are directly discharged to the tail area of the aircraft without acceleration; the regulation and control duration under different non-extended parameters is determined by the evolution time scale corresponding to the non-extended parameter. The application changes the electron distribution of the ionosphere aircraft tail area by randomly injecting high-energy electrons into the tail area of the aircraft, regulates and controls the evolution law and characteristic scale of the non-linear local cavity in the tail area which cannot be eliminated, makes the anti-stealth method of monitoring the motion of the density cavity to detect the ionosphere stealth aircraft invalid, and thus realizes the stealth of the ionosphere stealth aircraft.

Disclosed in the present application are a solar cell, a manufacturing method, an electrical device and a power generation device. The solar cell comprises a light-absorbing layer, the light-absorbing layer comprising a light-absorbing material and a passivation material, and the passivation material containing at least one of an organic amine or a derivative thereof. The passivation material provided by the embodiments of the present application contains nitrogen, nitrogen possess a lone pair of electrons, and the lone pair of electrons can enhance the binding capability between the passivation material and the light-absorbing material, so that the stability of the crystal structure of the light-absorbing material is improved, which helps the passivation material to passivate defects of the light-absorbing material and improve the film quality of the light-absorbing layer, thus improving the photoelectric conversion efficiency of solar cells.

The invention discloses an acupuncture anesthesia system which comprises a grounding device, a wire and an acupuncture needle, one end of the grounding device is used for being conductively connected with the ground, the other end of the grounding device is conductively connected with one end of the wire, and the other end of the wire is conductively connected with the acupuncture needle; negative electrons in the ground can sequentially flow through the grounding device, the wire and the acupuncture needle to enter acupuncture points and blood of a human body or an animal body. The grounding device is directly communicated with the ground, and a ground super-large capacitor is used as a stable electron source; efficient and stable electron transmission is realized through a conductive path constructed by a wire; by means of an automatic electronic conduction path formed by the grounding device, the wire and the acupuncture needle, negative electron injection and analgesia can be continuously carried out for a long time without continuous manual operation, and therefore the analgesia effect of needle anesthesia is comprehensively improved.

The present application relates to a kind of 2-phenyl substituted triarylethene photochromic material and preparation method and application, the prepared photochromic material can be by adjusting the steric hindrance and electron-withdrawing ability of 2-substituent group to the photochromic performance of triarylethene Realize significant regulation.This material has low raw material price, simple synthesis step, fast response and excellent fatigue resistance, so that the triarylethene material of original stimulus response single and between structure and photochromic property has no obvious rule is improved, is expected to have wide application prospect in high-speed information storage and fast biological imaging etc.In addition, the present application is suitable for anti-fake, photosensitive decoration, optical information storage, single-molecule logic gate, super-resolution fluorescence imaging, green printing and additive manufacturing etc. by different steric hindrance and electron-withdrawing substituent group to adjust photochromic color saturation.

The invention provides an improved camera for electron diffraction pattern analysis, and particularly relates to a device for detecting a Kikuchi diffraction pattern. The apparatus comprises: an electron column adapted to provide, in use, an electron beam directed toward the sample, the electron beam having an energy in the range of 2 keV to 50 keV, and; an imaging detector for receiving and counting electrons from the sample due to the interaction of the electron beam with the sample, the detector comprising an array of pixels and having a count rate capability of at least 2000 electrons per second for each pixel wherein: the imaging detector is adapted to provide electron energy filtering of the received electrons, the particle detector has an active region and a diffraction pattern for counting received electrons representing said diffraction pattern, and the particle detector has an inert layer on a surface on which electrons enter towards the active region of the detector, where the inert layer disperses the detection energy of 20 keV incident electrons having an energy dispersion of a full width at half maximum of less than 3.2 keV. The invention also provides a method for detecting the Kikuchi diffraction pattern.

The invention discloses a thin-film photovoltaic module and a method for improving the photoelectric conversion efficiency of the thin-film photovoltaic module, and the thin-film photovoltaic module comprises a glass layer, a front electrode layer, a power generation layer and a back electrode layer which are sequentially stacked together. The method for improving the photoelectric conversion efficiency of the thin-film photovoltaic module comprises the following steps: sequentially performing P1 and P2 scribing on a front electrode layer and a power generation layer of the thin-film photovoltaic module, and dividing the front electrode layer and the power generation layer into a plurality of independent sub-battery blocks; light emitted by a light source is controlled to penetrate through a plurality of independent sub-battery blocks obtained through the P1 scribed line and the P2 scribed line, so that the light is absorbed and converted into electron energy, and current is generated; respectively testing the current of the plurality of independent sub-battery blocks, and comparing the current of each sub-battery block with a current threshold to screen out abnormal sub-battery blocks of which the current is smaller than the current threshold; and controlling the back electrode layer of the thin film photovoltaic module to carry out P3 scribing, and skipping the screened abnormal sub-cell blocks during P3 scribing.

The application provides an ion source upper cover assembly and an ion source device. The fixed shielding cage in the ion source upper cover assembly can prevent the annular filament from being directly in contact with external structures to cause deformation or damage. The structure of the annular filament can effectively push the hot electrons emitted by the annular filament towards the ionization chamber, improve the ionization effect, and the ion source device is provided with the annular filament. The annular filament, the ionization cylinder and the shielding cage are coaxial, so that the electrons emitted by the annular filament can move in a more uniform electric field, thereby improving the probability of electron bombardment on the sample gas and improving the ionization efficiency and stability of the ion source device. Meanwhile, the ion source device has a wide range of emission current dynamic interval, strong anti-interference ability and wide range of sensitivity linear plateau area. The total pressure focusing electrode structure in the ion source device can also monitor the vacuum value in the detected space in real time, thereby playing a role in protecting the filament and the vacuum system.

This invention relates to the fields of organic synthesis and organic electronics, particularly to cyanobutadiene derivatives and their preparation methods and applications, and polymer semiconductor materials and their preparation methods and applications. The cyanobutadiene derivatives have the following general structural formula (1) or (2): This invention develops a series of cyanobutadiene derivative-based electron-deficient building blocks with simple structures, strong electron-withdrawing capabilities, and easy synthesis. These electron-deficient building blocks can be used as acceptor units in the development of organic photovoltaic, organic thermoelectric, and organic field-effect transistor materials.

This invention discloses a method and system for screening high-performance layered nitride thermoelectric materials, comprising: obtaining a series of crystal structures of initial layered nitrides; performing magnetic tests on the materials using first-principles calculations to select non-magnetic materials; optimizing the structure of non-magnetic materials, and after calculation convergence, performing static calculations and electronic band structure calculations to select materials with a band gap range of 0.1~3 eV and high band structure degeneracy; calculating the partial charge density of the materials to determine whether there is a two-dimensional electron gas, i.e., alternating conductive and insulating layers; determining stability by performing phonon spectrum and molecular dynamics simulations on the materials to select materials with no imaginary frequencies in the phonon spectrum and stable dynamics; calculating the thermal transport properties of the materials, obtaining the lattice thermal conductivity and Green'sson parameters, and searching for materials with strong anharmonicity; and finally performing electrical transport calculations to obtain the ZT value of the materials.

The invention discloses a method for estimating potential track microstructure damage of a GaN device under an electron energy loss mechanism. The method comprises the following steps: establishing a GaN device structure model; simulating the motion trail of the high-energy heavy ion incidence device through numerical calculation; calculating energy deposition space-time distribution of the high-energy heavy ions along the incident trajectory under the leading of the electron energy loss mechanism; solving the coupling dual-temperature heat conduction equation of the electronic system and the lattice atomic system to obtain the temperature space-time distribution of the lattice atomic system; according to the temperature space-time distribution of the lattice atomic system, whether latent track microstructure damage is generated or not is judged by comparing the highest temperature of the lattice atomic system with the melting point of a device crystal material; and under the condition of judging that the latent track damage is generated, drawing a temperature change curve chart of lattice atoms at different positions, and determining the position of the crystal atom of which the highest temperature is equal to the melting point of the crystal material as the radius size of the latent track microstructure damage. According to the method, the latent track microstructure damage characteristics of the device can be quantitatively and quickly obtained at low cost.

This invention discloses a polycyclic compound and an organic electroluminescent device containing the same. The invention introduces a bridged ring structure to reduce the electron-donating ability of nitrogen atoms, and further weakens this ability through a bridged ring and benzene ring structure, avoiding a redshift in the material's emission. Compared to the benzene ring, the twisted structure of the bridged ring weakens the intermolecular interactions caused by this planar configuration, which is more conducive to the dispersion of dopants in the host material, effectively avoiding fluorescence quenching and improving luminescence efficiency. Simultaneously, the use of a double boron framework allows the material to maintain a narrow half-width at half-maximum (WHM), resulting in devices fabricated using the compound of this invention exhibiting excellent performance in terms of efficiency and lifetime.

A DRAM device, including: a substrate; a plurality of bit lines located on the substrate, and disposed parallel to each other in a first horizontal direction; a plurality of word lines located on the bit line, and disposed parallel to each other in a second horizontal direction substantially perpendicular to the first horizontal direction; a plurality of channel patterns arranged in a honeycomb structure on the bit line, the plurality of channel patterns; a gate insulating pattern located between the plurality of channel patterns and the plurality of word lines; a plurality of switching insulating layers each formed on an upper surface of each of the plurality of channel patterns, at least a portion of which has a thickness that an electron can penetrate upon application of a voltage; and a plurality of control electrodes disposed parallel to each other to connect the plurality of switching insulating layers.

The application provides a gallium nitride-based semiconductor blue laser, which comprises, from bottom to top, a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer and an upper limiting layer, wherein a topological interface state layer is arranged between the upper waveguide layer and the upper limiting layer, and the topological interface state layer has breakdown field strength distribution characteristics and electron affinity energy distribution characteristics. Through the specific breakdown field strength distribution and electron affinity energy distribution of the topological interface state layer, a new body boundary energy band is formed, a strong spin center is formed at the interface, the coupling between adjacent interface states and the spin-splitting asymmetry of the electron band structure are enhanced, the spin-orbit torque effect is enhanced, the piezoelectric polarization and the thermal stress mismatch of the laser element are relieved, the valence band step is reduced, the uniformity of the valence band step is improved, the uniformity of the carrier injection into the active layer is improved, and the gain uniformity is improved.

This invention discloses a method for calculating the breakdown field strength of cable insulation of different thicknesses at different temperatures. The method includes the following steps: conducting surface potential decay experiments on XLPE samples of different thicknesses to obtain surface potential decay curves; obtaining trap parameters for XLPE samples of different thicknesses based on the surface potential decay curves; substituting the trap parameters into a bipolar carrier model to calculate the change in electron energy inside the XLPE sample with the applied pressure time; determining that the XLPE sample has broken down when the electron energy is greater than the trap energy level calculated from the surface potential decay experiment; recording the DC breakdown field strength of XLPE samples of different thicknesses at different temperatures to construct a DC breakdown field strength prediction model for XLPE samples. This invention can accurately evaluate the DC breakdown field strength of various types of XLPE samples, has the advantages of convenient operation and high universality, and shows high accuracy compared with actual experiments.

The invention belongs to the technical field of organic light-emitting materials and semiconductors, and particularly relates to a condensed ring organic compound containing boron and nitrogen heteroatoms and an electroluminescent device. According to the invention, a rigid condensed ring containing boron and nitrogen heteroatoms is taken as a parent nucleus, and a multi-element heterocyclic structure is introduced, so that the rigidity and steric hindrance of the parent nucleus are enhanced, the stability of the steric configuration of the compound is improved, and the electron donating capability of the parent nucleus is enhanced through a conjugation effect. Different electron donating / withdrawing groups are connected to specific positions on a rigid condensed ring containing boron and nitrogen heteroatoms for modification, and the constructed condensed ring organic compound containing boron and nitrogen heteroatoms has proper orbital energy level and triplet state energy, so that the efficiency of an organic light-emitting device is improved, and the service life of the organic light-emitting device is prolonged; the organic light-emitting material can be used as a high-performance light-emitting layer material or a hole transport layer or an electron transport layer to be applied to organic light-emitting devices.

The invention discloses a Micro-LED chip based on a passivation layer and a side wall metal layer and a preparation method, the Micro-LED chip comprises an LED structure and an electrode structure which are arranged on a substrate, and a first passivation layer and a dielectric layer which are sequentially arranged on the surface of the LED structure, and one side of the dielectric layer is provided with a metal layer; the LED structure sequentially comprises a first semiconductor layer, a light-emitting layer and a second semiconductor layer, and the first semiconductor layer and the second semiconductor layer are opposite in conduction type. According to the invention, low interface trap density and fixed charge density are realized through the first passivation layer on the surface of the LED structure, the non-radiative recombination of side wall carriers is significantly reduced, and the EQE of the Micro-LED chip is improved; forward bias voltage is applied through the dielectric layer / metal layer side wall structure, the energy difference between a surface defect state and an electron energy state is reduced, surface non-radiative recombination is reduced, EQE is improved, and the method is suitable for low-current-density operation.

The invention provides a multi-polar binary structure regulator and a preparation method and application thereof, sulfonic acid groups contained in the multi-polar binary structure regulator can give full play to the polar effect of polyamido and epoxy groups in the anionic polymerization process of conjugated diene (1, 3-butadiene), on one hand, the electron donating ability is greatly improved, and on the other hand, the polar effect of the polyamido and epoxy groups can be fully played; on one hand, the reaction is promoted to move towards a pi-lithium allyl structure, on the other hand, the association degree of the initiator is improved, and under the synergistic effect of the two aspects, the content of the 1, 2-structure can be efficiently regulated and controlled, so that the high-vinyl low-gel-content polybutadiene liquid rubber can be prepared.

According to the electron transport material provided by the invention, functional groups with strong electron withdrawing capability, such as triazine, pyridine and pyrimidine, are introduced to a parent nucleus, so that the electron mobility of the electron transport material can be effectively improved; the sp3 hybrid carbon at the 9 position of the fluorene ring can maintain the spatial configuration of the compound, the poor film-forming property and the short device life caused by molecular stacking are avoided, the specific functional group of the cyano group is introduced, the electron mobility of the electron transport material is further improved, the problem of electron-hole imbalance in the organic electroluminescent device is solved, and the organic electroluminescent device has good application prospects. Meanwhile, the high triplet state energy level (ET) and the wide band gap of the material are ensured, the luminous efficiency is further improved, the energy level matching degree of each layer of a device is improved, the driving voltage is reduced, the service life of the device is prolonged, and compared with the prior art, the material has excellent device performance.

The invention belongs to the technical field of electrochemistry and materials, and particularly relates to a device and a method for quantitatively detecting biochar electron transfer. The invention provides a device for quantitatively detecting biochar electron transfer. The device comprises an electrolytic reaction tank, a sulfuric acid electrolyte, a carbon-containing film working electrode, a counter electrode, a reference electrode and an electrochemical workstation, the carbon-film-containing working electrode comprises a working electrode and a carbon film loaded on the surface of the working electrode; the preparation raw material of the carbon film comprises biochar. According to the device for quantitatively detecting biochar electron transfer, sulfuric acid serves as electrolyte, the surface of the working electrode is coated with the carbon film containing biochar, and the obtained device is stable in system and has good anti-interference capacity; by constructing a hydrogen / oxygen evolution reaction kinetic model, a quantitative relationship between biochar electron transfer and reaction kinetic parameters is established, so that the problems that the existing biochar electron gaining and losing capability test mode and technical operation are complicated, and the detection sensitivity and the detection accuracy are low are solved.

This invention discloses a tetraazaisoindigo derivative and its preparation method. The structural formula of the tetraazaisoindigo derivative is shown in formula (I): where X and Y are both selected from H or N. This invention improves the core structure of isoindigo by introducing a more electron-deficient pyrazine or pyrimidine ring to replace the original benzene ring in isoindigo, thereby enhancing its electron-withdrawing ability, lowering the HOMO / LUMO energy levels, and obtaining an organic semiconductor material with better electron transport performance.

A method for determining electronic band structure includes partitioning, based on a location of each of a plurality of atoms forming a crystalline structure, a volume of the crystalline structure to obtain Voronoi tessellations. The method also includes constructing, based on the Voronoi tessellations, a plurality of crystal graphs and deriving, based on the plurality of crystal graphs, one or more local structural features of the crystalline structure. The method also includes feeding, into a trained machine-learning model, the one or more local structural features, one or more global structural features of the crystalline structure, and one or more species-based features of the crystalline structure. The trained machine-learning model, in response to said feeding, returns a plurality of energy values that sample a Brillouin zone of the crystalline structure.