Outer-shell Electrons Research Articles

Te L-subshell x-ray emission induced by lower energy H2+ ions

The L-shell x-ray emission of tellurium induced by H2+ ions impact is investigated in an energy range of 150–300 keV. The blue shifts of various L-subshell x rays and the enhancement of the relative intensity ratios of Lι, Lβ to Lα x ray are observed and interpreted by the multiple ionization of outer-shell electrons. The new experimental x-ray production cross sections, which almost correspond to those of protons with half of the original energy, are extracted and compared with various theoretical estimations. The correction effects of the united atom approximation and the multiple ionization atomic parameters are compared, and the influence of atomic parameters from different databases on the simulations is discussed. Overall, the ECUSAR-MI calculations using theoretical atomic parameters present the best agreement with the experiment results.

ALTERNATIVE EXPLANATION OF FILLING THE ELECTRONIC LAYERS OF ATOMS OF CHEMICAL ELEMENTS

The article provides a new approach to the formation of periods in Mendeleev's periodic system. Reconfiguration of the periods in the Mendeleev table using the newly proposed formula and the newly proposed quantum states for the outer electron shells of atoms of chemical elements is proposed. Purpose of work: Further development of the alternative theory of creation of electronic shells of atoms of chemical elements in D.I.Mendeleev's table. Results and discussions. The following order of formation of electron layers is proposed: principle quantum number (n), then the quantum state of the electrons forming the electronic configuration of the subperiods (first and second), and only then the remaining quantum orbitals (s, d, f and p). First and second new quantum states and a new formula for calculating the number of electrons in the outer electron shell of element periods and subperiods were proposed. The new level of electronic counting (II) and the new quantum number proposed by us allow to change the understanding of the internal structure of chemical elements without changing the general appearance and order of arrangement of chemical elements in D.I.Mendeleev's table itself, and therefore its contents. An important advantage of the proposed alternative model is that it takes into account and relies on already known, classical data for most of its main operational characteristics and is an extension of this important topic for classical chemistry theory. Therefore, the change in the number of periods, the introduction of a new quantum number in the form of D.I.Mendeleev's table, outwardly it does not differ much, but requires the necessary additional explanation. Concept. The proposed alternative approach to the structure and electronic structure of atomic shells of chemical elements in the periods and groups of D.I.Mendeleev's periodic system was recently developed by the authors and has good prospects for development primarily in the following directions: - identification of possible patterns of changes in the characteristics of chemical and physical properties of elements; - development of an accompanying model of the electronic structure of electronic shells of atoms of chemical elements of the proposed alternative model.

Liquid water radiolysis induced by secondary electrons generated from MeV-energy carbon ions.

Fast ion beams induce damage to deoxyribonucleic acid (DNA) by chemical products, including secondary electrons, produced from interaction with liquid water in living cells. However, the production process of these chemical products in the Bragg peak region used in particle therapy is not fully understood. To investigate this process, we conducted experiments to evaluate the radiolytic yields produced when a liquid water jet in vacuum is irradiated with MeV-energy carbon beams. We used secondary ion mass spectrometry to measure the products, such as hydronium cations (H3O+) and hydroxyl anions (OH-), produced along with ·OH radicals, which are significant inducers of DNA damage formation. In addition, we simulated the ionization process in liquid water by incident ions and secondary electrons using a Monte Carlo code for radiation transport. Our results showed that secondary electrons, rather than incident ions, are the primary cause of ionization in water. We found that the production yield of H3O+ or OH- was linked to the frequency of ionization by secondary electrons in water, with these electrons having energies between 10.9 and 550eV. These electrons are responsible for ionizing the outer-shell electrons of water molecules. Finally, we present that the elementary processes contribute to advancing radiation biophysics and biochemistry, which study the formation mechanism of DNA damage.

Encapsulation of Pd Single-Atom Sites in Zeolite for Highly Efficient Semihydrogenation of Alkynes.

Palladium (Pd)-based single-atom catalysts (SACs) have shown outstanding selectivity for semihydrogenation of alkynes, but most Pd single sites coordinated with highly electronegative atoms (such as N, O, and S) of supports will result in a decrease in the electron density of Pd sites, thereby weakening the adsorption of reactants and reducing catalytic performance. Constructing a rich outer-shell electron environment of Pd single-atom sites by changing the coordination structure offers a novel opportunity to enhance the catalytic efficiency with excellent alkene selectivity. Therefore, in this work, we first propose the in situ preparation of isolated Pd sites encapsulated within Al/Si-rich ZSM-5 structure using the one-pot seed-assisted growth method. Pd1@ZSM-5 features Pd-O-Al/Si bonds, which can boost the domination of d-electron near the Fermi level, thereby promoting the adsorption of substrates on Pd sites and reducing the energy barrier for the semihydrogenation of alkynes. In semihydrogenation of phenylacetylene, Pd1@ZSM-5 catalyst performs the highest turnover frequency (TOF) value of 33582 molC═C/molPd/h with 96% selectivity of styrene among the reported heterogeneous catalysts and nearly 17-fold higher than that of the commercial Lindlar catalyst (1992 molC═C/molPd/h). This remarkable catalytic performance can be retained even after 6 cycles of usage. Particularly, the zeolitic confinement structure of Pd1@ZSM-5 enables precise shape-selective catalysis for alkyne reactants with a size less than 4.3 Å.

Role of outer shell electron-nuclear distant of transition metal atoms (TMA) on band gap reduction and optical properties of TiO2 semiconductor

The reduction of the band gap of titanium dioxide (TiO2) via transition metal atoms (TMAs) is the focus of many research groups to increase its absorption to visible region of electromagnetic (EM) radiation. In this modeling it was shown that atoms having near outer electron shells affect strongly on the band gap of TiO2. The TiO2 has exceptional photoactivity, high stability, and cost-effectiveness. The results of the current study emphasized that adjustable TiO2 photocatalyst material can be produced through band gap reduction by Pt, Pd, and Ni dopants. The electronic configurations and optical properties of both undoped and (Ni, Pd and Pt)-doped TiO2 have been studied using first-principles calculations within the framework of Density Functional Theory (DFT) with the aid of the Vienna Ab initio Simulation Package (VASP). The role of electronegativity of TMAs on band gap drop was discussed for the first time. The band gap of clean TiO2 was found to be 3.2 eV using the band structure (BS) and Tauq model. The results indicate that Ni TMA with lowest electronegativity reduces the band gap of TiO2 to the lowest value (0.86 eV). The results of BS and density of state revealed the fact that small outer shell electron-nuclear distant TMA more affected the band gap of TiO2. The band gap determined from the imaginary part of the optical dielectric function closely aligns with those determined from the BS diagram. The increase in the refractive index (n) was observed with the increase of Ni, Pd, and Pt into the TiO2 structure, which indicates an increase in charge density within the TiO2 structure. The reflectance, absorbance, and transmittance results suggest that Pd and Pt-doped TiO2 are responsive to the visible region of electromagnetic radiation, whereas Ni-doped TiO2 exhibits responsiveness in the IR region. In its pure state; TiO2 was found almost transparent in the visible and IR regions of EM radiation.

Construction of spinel (Fe0.2Co0.2Ni0.2Cr0.2M0.2)3O4 (M = Mg, Mn, Zn, and Cu) high-entropy oxides with tunable valance states for oxygen evolution reaction

High-entropy oxides (HEOs) exhibit excellent structural stability, and the synergistic effects among their constituent elements contribute to performance enhancement, providing vast opportunities for designing novel and efficient electrocatalysts. Utilizing four common transition metals such as Fe, Co, Ni, and Cr as the base and introducing a fifth metal, M (M = Mg, Mn, Zn, and Cu), with different outer electron shells, relevant high-entropy oxides with varying sizes were successfully synthesized via the hydrothermal method. Among all considered samples, FCNCMg, with the smallest particle size, possessed a much larger specific surface area, leading to the exposure of more active sites and thus favoring an improvement of the OER performance. The introduction of the fifth metal induced a redistribution of charges among Fe, Co, Ni, and Cr within the catalyst, resulting in different oxidation states for these metals. Mg addition led the XPS peaks of Fe/Ni and Cr/Co elements to shift towards lower and higher binding energies, respectively. This dynamic compensation effect between metal ions synergistically promoted their OER performance. In alkaline environments, FCNCMg exhibited the best OER performance, with an overpotential of 278 mV at 10 mA cm−2 and a Tafel slope of 49.90 mV dec−1. Moreover, it demonstrated excellent stability, achieving 50 h at 10 mA cm−2 and 20 h at 50 mA cm−2. This study, by controlling the composition of HEOs, explored the impact of particle size and synergistic effects on their performance, offering new insights for design and optimization of relevant high-performance HEOs.

Regulating Chemisorption and Electrosorption Activity for Efficient Uptake of Rare Earth Elements in Low Concentration on Oxygen-Doped Molybdenum Disulfide.

Recovery of rare earth elements (REEs) with trace amount in environmental applications and nuclear energy is becoming an increasingly urgent issue due to their genotoxicity and important role in society. Here, highly efficient recovery of low-concentration REEs from aqueous solutions by an enhanced chemisorption and electrosorption process of oxygen-doped molybdenum disulfide (O-doped MoS2) electrodes is performed. All REEs could be extremely recovered through a chemisorption and electrosorption coupling (CEC) method, and sorption behaviors were related with their outer-shell electrons. Light, medium, and heavy ((La(III), Gd(III), and Y(III)) rare earth elements were chosen for further investigating the adsorption and recovery performances under low-concentration conditions. Recovery of REEs could approach 100% under a low initial concentration condition where different recovery behaviors occurred with variable chemisorption interactions between REEs and O-doped MoS2. Experimental and theoretical results proved that doping O in MoS2 not only reduced the transfer resistance and improved the electrical double layer thickness of ion storage but also enhanced the chemical interaction of REEs and MoS2. Various outer-shell electrons of REEs performed different surficial chemisorption interactions with exposed sulfur and oxygen atoms of O-doped MoS2. Effects of variants including environmental conditions and operating parameters, such as applied voltage, initial concentration, pH condition, and electrode distance on adsorption capacity and recovery of REEs were examined to optimize the recovery process in order to achieve an ideal selective recovery of REEs. The total desorption of REEs from the O-doped MoS2 electrode was realized within 120 min while the electrode demonstrated a good cycling performance. This work presented a prospective way in establishing a CEC process with a two-dimensional metal sulfide electrode through structure engineering for efficient recovery of REEs within a low concentration range.

Modulating Hydroxyl Adsorption on Transition Metal Nitrides by Magnetic Moments toward Fast Alkaline Hydrogen Evolution

Water dissociation is a critical step limiting the kinetics of electrocatalytic hydrogen evolution reaction (HER) in the alkaline. However, the effect of hydroxyl groups (OH*) on the electrocatalyst surface during the HER process has not been clarified yet. Here, three typical transition metal (TM) nitrides (i.e., Fe2N, Co3N and Ni3N) were investigated by combing theoretical calculation and experiments toward alkaline HER. The results show binding energy of OH* (∆EOH*) and magnetic moment of three nitrides follow the same trend of Fe2N > Co3N > Ni3N, showing a positive correlation. The as-synthesized Ni3N with the smallest magnetic moment shows the best alkaline HER activity due to its lowest water-dissociation barrier and weakest ∆EOH*. Weak adsorption to OH* could promote the fast release of OH* and thus enhance reaction kinetics. A small bond order corresponding to weak interaction between Ni3N and OH* is found to be favorable to the release of OH* and subsequent reaction steps, which originates from the orbital interaction of outer-shell electrons in TM and OH*. This work provides new insights into the design of advanced electrocatalysts using magnetic matrix toward alkaline HER.

Değişen Sıcaklık Koşullarının LiNi2Sn Malzemesinin Elektronik Seviyeleri Üzerine Etkilerinin Araştırılması: Bir Ab-Initio Çalışması

In this study, the electronic and crystal structures of the LiNi2Sn material—reported to have a stable crystal structure but not yet thoroughly studied—were examined at various temperatures, and traces of the thermoelectric property were looked for in light of the results. A test research was carried out with a fresh perspective on the thermoelectric property traces on the electrical and crystal structures in order to promote the studies of thermoelectric materials, and the results were provided with complete analysis. Theoretical investigations using X-ray absorption fine structure (XAFS) spectroscopic calculations were made into the electronic structural characteristics of the LiNi2Sn material. Calculations were made with XAFS code FEFF 8.20 under increasing temperature conditions of 300 K, 323 K, 373 K, and 423 K. Findings from the study included the quantity and potency of the atoms' outer shell electrons, which are where the photoelectrons are directed. The results of the study are compatible with the literature data.

Super weak Electromagnetic Radiation in Bio and Inorganic Systems

This article provides a comparative analysis of data on ultra-weak electromagnetic radiation (WEEM) obtained at different times from bio and inorganic systems. The unifying physical principle was the presence of hybrid orbitals in the outer electron shells in the systems under study and the generation of coherent radiation in them. The data of a model experiment on ultra weak radiation of metals and semiconductors in the long-wavelength region of the optical spectrum are presented, indirectly confirming this hypothesis.

Energy reemission and possible radiosensitizing effect caused by the cascade decay of single vacancies in the K, L, M, and N shells of atomic silver

Cascade decays of single vacancies in the K, L, M, and N shells of the silver atom are studied using the method of straightforward construction and analysis of the cascade de-excitation trees with inclusion of additional shake-off ejections of outer-shell electrons caused by the change of atomic core potential due to cascade transitions. The spectra of the cascade-produced electrons and photons emitted upon the decay of single vacancies in 1s1/2 to 4p3/2 subshells are calculated. For each initial vacancy, the energies absorbed by the silver atom itself, and those carried away by cascade electrons and photons, are calculated. Absorption of energy by the silver atom itself is only significant upon N- and M-shell ionization (49–66% and 18–36%, respectively), i.e. in the UV to soft X-ray range. After L- to N-ionization, most of the acquired energy is reemitted with cascade electrons, respective portions making 81–85% during L-ionization, 62–82% during M-ionization, and 34–51% during N-ionization. Reemission of energy with cascade photons is dominant after K-ionization (76%). When silver atoms are used as radiosensitizing agents in radiotherapy, cascade electrons play the principal role in the energy transfer to organism tissues. Due to small free paths in the organic medium, they give their energy to the environment in rather small volumes inside a particular cell where they are placed. As for the photons emitted after K-ionization, they transfer energy to the medium in much larger volumes, and with much smaller absorbed doses.

Giant NLO response and ultraviolet transparency of superalakalis decorated C6O6Li6 complexes; a DFT perspective

Materials having nonlinear optical (NLO) properties are the demand of optics and optoelectronics fields because of their widespread applications. Keeping in view the applications of NLO materials, some new superalkalis doped C6O6Li6 complexes are introduced in this study having remarkable NLO response. Thermodynamic stability of nonlinear optical materials (NLO) is prime requirement of experimentalists for practical applications. All the considered complexes have high thermodynamic stability. Furthermore, these superalkali doped complexes reveal fabulous electronic properties. Superalkalis shift their outer shell electrons towards the C6O6Li6 nanocluster, which act as diffuse excess electrons. The HOMO-LUMO gaps (H-L Egap) of superalkali doped complexes are effectively reduced due to shifting of electrons that reveals their conducting properties. NBO charge analysis confirmed electron charge transfer from superalkalis to C6O6Li6 surface. Linear and NLO properties of these complexes are estimated from first order polarizability (α o) and hyperpolarizability (β o) parameters. Among all complexes, C6O6Li6.K3O has the highest first hyperpolarizability (β o = 6.02 × 105 au). TD-DFT analysis confirmed the ultraviolet transparency of doped complexes. Two level model is used to rationalize the trend of first hyperpolarizability and the internal factors responsible for the enhancement of NLO response.

Au L-shell x-ray emission induced by 154.3–423.9 MeV/u C6+ ions

The L-shell x-ray emissions of gold are investigated for the bombardment of high energy C6+ ions in the high energy region of 154.3–423.9 MeV/u. Due to the multiple ionization of outer-shell electrons at the movement of L x-ray emission, the blue shift of the experimental x-ray energy and an enhancement of the relative intensity ratios of Lι, Lβ–Lα x rays are observed. Using the improved thin target formula and considering the effect of multiple ionization on atomic parameters, the L-subshell x-ray production cross sections are extracted from the counts and compared with the theoretical estimations of BEA, PWBA and ECPSSR. It is found that the relative corrections of ECPSSR on PWBA can be ignored in the present experimental energy region. The calculations of PWBA and ECPSSR are almost identical and both are larger than the experimental results. The BEA is in better agreement with the experiment as a whole.

Correlation between the activity of Fe@ (N, S, and P) doped graphene catalysts and the coordination environment: A density functional theory study

Transition metal-doped graphene single-atom catalysts exhibit great application prospects for catalyzing hydrogen evolution applications. However, the precise timing and control of the activity of central atoms is a key problem to ensure the further development of catalysts. Revealing the correlation between the catalytic activity of the central atom and the coordination environment (atomic species, coordination number, and geometric configuration) is regarded as quite crucial for solving this key problem. Along these lines, in this work, Fe as the central atom and N, S, and P doped porous graphene (DPG) as the matrix material were used to systematically study the correlation between the coordination environment and the stability, catalytic activity of the catalyst. From the acquired results, it was demonstrated that: (1) The binding strength between the Fe atom and the N-atom DPG is the highest, and the anchoring strength of the Fe atom on two-element doping doped graphene is relatively low. Under the tetrad coordination condition, the catalyst doped with S and P atoms showed excellent performance in hydrogen evolution and water activation. A moderate correlation between the hydrogen evolution performance (ΔGH∗, EA, and ΔGOH∗) and d-band electronic properties (d-CU and d-SE) under single element doping (four and three coordination) was also detected. In addition, a certain correlation between the Fe atom outer-shell electron (3d 4s) and the hydrogen evolution performance was found. A weak correlation between the electronic properties of the double element doped graphene and the hydrogen evolution performance was also confirmed from our simulations. The results are of great significance for the regulation of the single-atom catalyst activity.

Stability and bonding of carbon(0)-iron-N2 complexes relevant to nitrogenase co-factor: EDA-NOCV analyses.

The factors/structural features which are responsible for the binding, activation and reduction of N2 to NH3 by FeMoco of nitrogenase have not been completely understood well. Several relevant model complexes by Holland et al. and Peters et al. have been synthesized, characterized and studied by theoretical calculations. For a matter of fact, those complexes are much different than real active N2 -binding Fe-sites of FeMoco, which possesses a central C(4-) ion having an eight valence electrons as an μ6 -bridge. Here, a series of [(S3 C(0))Fe(II/I/0)-N2 ]n- complexes in different charged/spin states containing a coordinated σ- and π-donor C(0)-atom which possesses eight outer shell electrons [carbone, (Ph3 P)2 C(0); Ph3 P→C(0)←PPh3 ] and three S-donor sites (i.e. - S-Ar), have been studied by DFT, QTAIM, and EDA-NOCV calculations. The effect of the weak field ligand on Fe-centres and the subsequent N2 -binding has been studied by EDA-NOCV analysis. The role of the oxidation state of Fe and N2 -binding in different charged and spin states of the complex have been investigated by EDA-NOCV analyses. The intrinsic interaction energies of the Fe-N2 bond are in the range from -42/-35 to -67 kcal/mol in their corresponding ground states. The S3 C(0) donor set is argued here to be closer to the actual coordination environment of one of the six Fe-centres of nitrogenase. In comparison, the captivating model complexes reported by Holland et al. and Peter et al. possess a stronger π-acceptor C-ring (S2 Cring donor, π-C donor) and stronger donor set like CP3 (σ-C donor) ligands, respectively.

Bethe stopping-power formula and its corrections

The classical and quantum theories leading to the asymptotic Bethe formula of the stopping power of matter for charged particles heavier than the electron are briefly reviewed. Models and approximations for the practical calculation of various corrections that extend the validity range of the formula are described. The asymptotic formula and the associated shell correction were determined previously from an extensive database of atomic generalized oscillator strengths, calculated for an independent-electron model with the Dirac-Hartree-Fock-Slater (DHFS) self-consistent potential, with due account for relativistic departures from the Bethe sum rule. The nonrelativistic Bloch correction is extended to the relativistic domain by means of the Lindhard-S\o{}rensen formulation, and an accurate parametrization for point projectiles with small charges is proposed. The density-effect correction and the Barkas correction are obtained from a semiempirical model of the optical oscillator strength (OOS), built from the calculated DHFS contributions of inner electron subshells plus the OOS of outer-shell electrons represented by an analytical expression, which is determined by the composition, mass density, and empirical mean excitation energy, or $I$ value of the material. Inclusion of the shell, density-effect, Lindhard-S\o{}rensen, and Barkas corrections into the asymptotic formula leads to the corrected Bethe formula. A general strategy is proposed to determine the stopping power in terms of only the $I$ value of the material. It is shown that, with the empirical $I$ values recommended in Report 37 of the International Commission on Radiation Units and Measurements, the stopping powers calculated numerically from the corrected formula are in close agreement with available measurements of the stopping power of elemental materials for protons and alpha particles with energies higher than 0.75 and 5 MeV, respectively.

Voltammetric Analysis of the Ferrocenium/Ferrocene Redox Couple in Litfsi-Acetonitrile Highly Concentrated Electrolyte

Research on electrolytes have a defining role for the progression of current energy storage device and electrocatalysis. For instance, the electrolyte is often a limiting factor in the life span of Li-ions batteries due to slow decomposition at electrodes. Intensive research is therefore ongoing to increase the stability of the electrolyte. One example of such research is on highly concentrated electrolyte (HCE) which are obtained when the number of ions of a salt nears or equals that of the solvent molecules, while maintaining a liquid state. These highly concentrated electrolytes (HCE) or "solvent-in-salt" solutions differ in properties from conventional ones because all solvent molecules are occupying the ion solvation sphere where they are strongly coordinated to the cation. While on the application side, the attention is directed towards their use in batteries or supercapacitors, current research on HCE aims at increasing the fundamental understanding of their properties mostly the transport properties of the Li+ or the formation of the solid electrolyte interface (SEI). Interestingly, there are no reports on the study of heterogeneous electron transfer (ET) in HCE, yet the absence of "free" solvent molecule suggests that ET in HCE might be different from conventional electrolytes because of the importance of solvent reorganization during ET. We therefore investigate the mass transport and ET of dissolved ferrocene (Fc) and with ferrocene terminated self-assemble monolayer, (Fc-SAM). Ferrocene was selected as the redox center for its "ideal" outer shell electron transfer mechanism and well-defined electrochemical properties. To establish the effect of salt concentration, the electrochemical measurements were done in a series of electrolytes composed of Lithium bis(trifluoromethanesulfonyl)imide in acetonitrile with concentrations spanning from diluted (0.3 M) to highly concentrated (4.1 M) solutions. The diffusivity of Fc (Shoup-Szabo) is found to follow the trend with viscosity (η) expected from the Stokes-Einstein relation over the entire concentration range. The ET rate constant k0 variation with η on the other hand diverges from what is expected from a purely adiabatic ET. Possible explanations for deviation involve different dielectric properties, strong coordination of the solvent and particular double-layer structure of HCE, properties that are not fully established. This lack of knowledge highlights the importance of increasing fundamental research on the topic of electrochemistry in HCE.

Effects of preliminary ion beam treatment of carbon nanotubes on structures of interfaces in МОх/multi-walled carbon nanotube (M =Ti,Sn) composites: Experimental and theoretical study

In this study, ion beam treatment was investigated as a method for functionalizing the surfaces of multi-walled carbon nanotubes (MWCNTs) employed in the production of composites with titanium and tin oxides using magnetron sputtering. Preliminary ion irradiation of MWCNTs obtained a uniform distribution of metal oxides over their surfaces. According to the experimental results, interfacial adhesion in the composites was increased due to the interactions between metal oxides and oxygen-containing functional groups on the surfaces of the MWCNTs. Quantum chemical calculations demonstrated the possibility of M-O-C bonds (M = Ti, Sn) forming with the participation of CO groups fixed on the graphene plane near vacancy-type defects. The features of Ti–O–C and Sn–O–C bonds were investigated based on electron density difference analysis and the density of states of the outer electron shells.

Photon Emission from Hollow Ions Near Surfaces

Ions with multiple inner-shell vacancies frequently arise due to their interaction with different targets, such as (intense) light pulses, atoms, clusters or bulk material. They are formed, in addition, if highly charged ions approach surfaces and capture electrons at rather large distances. To explore the interaction of such hollow ions and their subsequent relaxation, photon spectra in different frequency regions have been measured and compared to calculations. To support these and related measurements, we here show within the framework of the Jena Atomic Calculator (Jac) how (additional) electrons in outer shells modify photon emission and lead to characteristic shifts in the observed spectra. Further, for highly charged Ar ions in KLm(m=1…8) configurations, we analyze the mean relaxation time for their stabilization into the different ground configurations. These examples demonstrate how a powerful and flexible toolbox such as Jac will be useful (and necessary) in order to model the photon and electron emission of ions as they occur not only near surfaces but also in astro-, atomic and plasma physics.

Arsenene nanotubes adsorbed with various non-metallic atoms: Chemical bonding, odd-even effect, and electronic transport

The recently experimental fabricated arsenene has attracted extensive research interest due to its excellent physical and chemical properties. To further explore new physics and extend its realistic applications, we here theoretically study the chemical bonding and electronic properties for its 1D derivatives, zigzag arsenene nanotubes, adsorbed with various non-metal atoms in main groups. The calculated adsorption energy and molecular dynamics simulation suggest that these hybrid tubes are very stable with different adsorption sites. Importantly, our investigations reveal many novel interesting physical regularities. For example, for the atom adsorption from the same main-group, the higher the atomic number is, the lower (shorter/less) the corresponding adsorption energy (minimum bond length/charge transfer) is, and the amount of charge transfer closely related to the electronegativity of the adsorbent atoms relative to As atom. More interestingly, we find that the electronic phase (a metal or semiconductor) of the hybrid tubes changes alternately with the elemental group order, that is, the electron phase holds a significant odd-even effect with non-metal atomic outer-shell electron number, closely related to the unpaired electronic state. The mechano-electronic coupling effect can tune the indirect band gap to a smaller direct band gap under higher tensile strain for these hybrid tubes, more beneficially for light absorption and developing photoelectric devices, and the different non-metal atom adsorptions can regulate the carrier mobility and the carrier polarity to two and one orders of magnitude difference, respectively.