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A comprehensive investigation of the unexplored mechanical, electronic, Mulliken bond population, vibrational, optical and thermophysical properties of the synthesized compounds NbInX2 (X = S, Se) have been made for the first time using the density functional theory. The chemical, mechanical and dynamical stabilities of the compounds are established in our calculations. Both compounds are soft, machinable and brittle. The anisotropic nature of the studied compounds is shown by 3D representations of elastic moduli. The density of states and electronic band structure demonstrate that the compounds are metallic. Fermi surfaces of both compounds are almost similar and contain both hole- and electron-like topologies. The characteristics of chemical bonding among different atoms of the compounds are studied via a charge density distribution map and bond population analysis. Both the compounds possess optical anisotropy. Reflectivity is high (above 44%) in the IR–visible–UV region indicating that the phases may be effective in reducing solar heat. Minimum thermal conductivity, kmin (used to select appropriate material for thermal barrier coating) and its anisotropy are calculated for the first time. The results show that both compounds have kmin much smaller than the reference value of 1.25Wm−1K−1. [ABSTRACT FROM AUTHOR]

Combined with the genetic algorithm and CALYPSO software, the geometrical and electronic structures of the ground states of Mon(n=2-13) and MonC (n=1-12) clusters were studied in detail by density functional theory. The average bond length, average binding energy, second-order difference energy, splitting energy and Highest Occupied Molecular Orbital - Lowest Unoccupied Molecular Orbital (HOMO-LUMO) of the ground state structure were calculated to investigate the stability of the ground state structure with respect to the total atomic number. The calculated results showed that the stability of the ground-state structures of Mo, clusters could be improved by doping with individual C atoms. The second-order differential energy and splitting energy of the clusters were combined to show that the stability of Mo, clusters is higher at n = 6 and 9, and that of Mon C clusters is higher at n =4, 7 and 10. [ABSTRACT FROM AUTHOR]

Ripples on graphene play a crucial role in manipulating its physical and chemical properties. However, producing ripples, especially at the nanoscale, remains challenging with current experimental methods. In this study, we report that tiny ripples in graphene can be generated by the adsorption of a single metal cation (Na+, K+, Mg2+, Ca2+, Cu2+, Fe3+) onto a graphene sheet, based on the density functional theory calculations. We attribute this to the cation–π interaction between the metal cation and the aromatic rings on the graphene surface, which makes the carbon atoms closer to metal ions, causing deformation of the graphene sheet, especially in the out-of-plane direction, thereby creating ripples. The equivalent pressures applied to graphene sheets in out-of-plane direction, generated by metal cation–π interactions, reach magnitudes on the order of gigapascals (GPa). More importantly, the electronic and mechanical properties of graphene sheets are modified by the adsorption of various metal cations, resulting in opened bandgaps and enhanced rigidity characterized by a higher elastic modulus. These findings show great potential for applications for producing ripples at the nanoscale in graphene through the regulation of metal cation adsorption. [ABSTRACT FROM AUTHOR]

The effects of different Mn concentrations on the generalized stacking fault energies (GSFE) and elastic properties of MnxCoCrFeNi high-entropy alloys (HEAs) have been studied via first-principles, which are based on density functional theory. The relationship of different Mn concentrations with the chemical bond and surface activity of MnxCoCrFeNi HEAs are discussed from the perspectives of electronic structure and work function. The results show that the plastic deformation of MnxCoCrFeNi HEAs can be controlled via dislocation-mediated slip. But with the increase in Mn concentration, mechanical micro twinning can still be formed. The deformation resistance, shear resistance, and stiffness of MnxCoCrFeNi HEAs increase with the enhancement of Mn content. Accordingly, in the case of increased Mn concentration, the weakening of atomic bonds in MnxCoCrFeNi HEAs leads to the increase in alloy instability, which improves the possibility of dislocation. [ABSTRACT FROM AUTHOR]

Recently, bulk Mg3X2 (X=As, Sb) have been intensively studied for their unique properties for thermoelectric use. However, studies on their two-dimensional counterparts are not sufficient. In this work, we systematically investigated the electronic, mechanical, vibrational, and piezoelectric properties of Mg3X2 (X = As, Sb) monolayers. The results indicate that both monolayers have negative formation energies with dynamical and mechanical stability. Mg3As2 monolayer is a narrow band gap semiconductor, while Mg3Sb2 monolayer is an indirect one. The origin of the band structure was revealed by the calculated partial density of states. The bonding property of both monolayers was analyzed by different methods. Elastic constants were obtained by density functional perturbation theory, and the related physical quantities were derived and analyzed. In-plane strengths along the zigzag and armchair directions of both materials were calculated, and the fracture mechanisms were uncovered. The vibrational modes at the Brillouin center were classified through group theory analysis, and the corresponding eigenvectors and frequencies were calculated and presented. Infrared vibrational spectra were simulated, and the reason for the vanishment of some infrared peaks was disclosed. Piezoelectric and dielectric coefficients were also computed and discussed. [ABSTRACT FROM AUTHOR]

In this work, we have studied the electronic properties of SnO2 by employing the density functional theory. The aim of the work is to study the comparative effect of Te doping in SnO2 in Sn and O sites. The CASTEP module is used for the simulation. 2 × 2 × 2 lattice of SnO2 was used for the study of the band structure and density of state. The electronic properties change significantly on doping the sample with Te. Also, when Te is doped in different quantities and at different sites in SnO2, the bandgap is overlapped in 0.75% Te doping at O site and the maximum is found to be 0.587 eV in 0.75% Te doping at Sn site. For pure SnO2, the bandgap is 1.064. Hence SnO2 when doped with Te influences the conductivity. [ABSTRACT FROM AUTHOR]

This paper systematically investigates the structure, stability, and electronic properties of niobium carbide clusters, NbmCn (m = 5, 6; n = 1–7), using density functional theory. Nb5C2 and Nb5C6 possess higher dissociation energies and second-order difference energies, indicating that they have higher thermodynamic stability. Moreover, ab initio molecular dynamics (AIMD) simulations are used to demonstrate the thermal stability of these structures. The analysis of the density of states indicates that the molecular orbitals of NbmCn (m = 5, 6; n = 1–7) are primarily contributed by niobium atoms, with carbon atoms having a smaller contribution. The composition of the frontier molecular orbitals reveals that niobium atoms contribute approximately 73.1% to 99.8% to NbmCn clusters, while carbon atoms contribute about 0.2% to 26.9%. [ABSTRACT FROM AUTHOR]

Double traditional metal (TM) Janus MXenes have more superior properties when compared with MXenes. The electronic and optical properties, Bader charge and quantum capacitance of ZrMCO 2 (M = Sc, Ti, V, Cr, Mn, Fe, Y, Zr, Nb, Mo, Hf, Ta, W) are explored by density functional theory (DFT). The stability of these systems is confirmed by cohesive energy. The substitution of Ti/Hf atoms results in the decrease of bandgap of ZrTiCO 2 /ZrHfCO 2 , which is induced by the redshift of conduction band minimum (CBM). ZrMCO 2 (M = Cr, Mn) are magnetic semiconductors and ZrMCO 2 (M = Sc, V, Y, Fe) are magnetic metals. All doping atoms except Hf improve the maximum quantum capacitance of ZrMCO 2 at positive bias. Wide voltage makes ZrMCO 2 (M = Nb, Ta, W) change into anode material and ZrFeCO 2 into cathode material. ZrMCO 2 (M = Sc, Mn, Y, Hf, Zr) and ZrMCO 2 (M = V, Cr) can serve as cathode and anode materials in whole voltage, respectively. Much charge accumulating between Fe and C atoms results in the smallest Fe–C bond among all M − C bonds, which indicates the strongest interaction between Fe and C atoms. Optical properties and work function are further explored. [ABSTRACT FROM AUTHOR]

Making products that are affordable, environmentally friendly, and energy‐efficient is the main objective of modern production. The objective of this research is to discover compounds that meet these parameters. The full‐potential, linearized augmented plane wave program (FP LAPW) offered by Wien2K was used to examine the structural, optical, electrical, and transport aspects of SrCaGe and SrCaSn Half‐Heusler (HHs) compounds. Generalized gradient approximation (GGA) was considered for the structural optimization and computation of elastic properties signifies inherent ductility and mechanical stability of the examined SrCaGe and SrCaSn compounds. Additionally, both materials were found to possess a direct bandgap and exhibit semiconducting behavior. The bandgap magnitudes obtained utilizing the modified Becke‐Johnson (mBJ) approximation are 0.78 and 0.52 eV for SrCaGe and SrCaSn, respectively. According to their optical characteristics, SrCaGe and SrCaSn show potential for application in optoelectronic components. Furthermore, the transport properties are evaluated by BoltzTrap program, revealing that both SrCaGe and SrCaSn exhibit figures of merit (ZT) values nearly equal to one at room temperature. This suggests their potential use in creating thermoelectric devices with highly efficient performance. The simulation study demonstrates the promising attributes of SrCaGe and SrCaSn HHs materials, positioning them as viable candidates for various applications, aligned with the goals of sustainable and efficient manufacturing. [ABSTRACT FROM AUTHOR]

Two-dimensional van der Waals heterostructures (vdW-HSs) have emerged as a promising method for designing high-performance nanoscale optoelectronic devices such as solar cells. Herein, we propose the vdW-HS BAs/MoSi2P4 within the context of density functional theory (DFT). The results demonstrate that the BAs/MoSi2P4 heterostructure showcases a direct band gap and exhibits a notable type II band alignment feature that enables the efficient charge separation of photoinduced electron–hole pairs. The optical absorption intensity of the individual monolayers (BAs and MoSi2P4) is significantly enhanced upon the formation of a vdW-HS. The carrier mobility of the vdW-HS is significantly high compared to that of the MoSi2P4 monolayer. The findings of our study demonstrate the potential of BAs/MoSi2P4 vdW-HS as a desirable candidate for next-generation optoelectronic devices. [ABSTRACT FROM AUTHOR]

First principles calculations based on density functional theory (DFT) were performed to investigate the structural, electronic, optical and mechanical properties of pristine GaAs compound and its alloy; Ga0.75Al0.25As, Ga0.75In0.25As, Ga0.75Sn0.25As, Ga0.75Ti0.25As. WIEN2K and Quantum expresso (QE) codes were adopted for calculations using generalized gradient approximation (GGA) in Perdew-Burke Erzenhoff (PBE) as exchange correlation function for both codes. Full potential linear augmented plane wave (FPLAPW) with the local orbital method was adopted as implement in WIEN2K code. In QE code, norm-conserving pseudopotentials were employed on a plane-wave expansion of the wave functions. Structural and electronic properties were elaborated since their result gives information about the optical and mechanical performance. Electronic band structure and optical parameters were performed using WIEN2K code. Underestimation of band gap observed from DFT calculations were corrected by using Modified Becke and Johnson (mBJ). Mechanical components were determined using QE with thermo_pw package. Lattice constant, volume, bulk modulus and other physical parameters were calculated for structural properties. Discrepancy in these parameters as observed in crystal structure is associated to difference in ionic radius of host and substituted atom. The results of band structure and density of states were calculated for electronic properties. All the studied compounds were semiconductors in nature except Ga0.75Sn0.25As which displayed metallic character. Optical parameters including extinction coefficient, absorption coefficient, refractive index, optical conductivity, optical reflectivity and energy loss function have been computed from the dielectric function at energy range of 0 to 25 eV using the Kramers-Kronig transformations. Calculated elastic function were used to compute the mechanical properties such as anisotropic, brittle characteristics, stiffness and many others. All the results were compared with available theoretical and experimental records.

This paper systematically investigates the structure, stability, and electronic properties of niobium carbide clusters, NbmCn (m = 5, 6; n = 1–7), using density functional theory. Nb5C2 and Nb5C6 possess higher dissociation energies and second-order difference energies, indicating that they have higher thermodynamic stability. Moreover, ab initio molecular dynamics (AIMD) simulations are used to demonstrate the thermal stability of these structures. The analysis of the density of states indicates that the molecular orbitals of NbmCn (m = 5, 6; n = 1–7) are primarily contributed by niobium atoms, with carbon atoms having a smaller contribution. The composition of the frontier molecular orbitals reveals that niobium atoms contribute approximately 73.1% to 99.8% to NbmCn clusters, while carbon atoms contribute about 0.2% to 26.9%.

This research presents within the full potential linearized augmented plane wave (FP-LAPW) technique with the first-principles calculations to investigate the structural, electronic, elastic and optical properties of ternary cubic perovskites of the form TlXF3 (X= Ag and Pd) compounds. All these calculation is done by WIEN2k code within the density functional theory (DFT). The modified Becke-Johnson potential (TBmBJ) is used for the optical and electronic properties. TDOS and PDOS analysis shows that both TlAgF3 and TlPdF3 are structurally stable and the main contribution of the states in TlAgF3 compound is due to the Tl (d-orbitals) atoms and that in TlPdF3 compound, F (p-states) contributes the more. The electronic-band structure analysis shows the metallic properties having no band gaps. Optical properties are also discussed using dielectric function. Elastic calculation revealed that both compounds are anisotropic, brittle and ionic. [ABSTRACT FROM AUTHOR]

The growth behavior, stability, electronic and magnetic properties of the Gd2Sin− (n = 3–12) clusters are reported, which are investigated using density functional theory calculations combined with the Saunders 'Kick' and the Artificial Bee Colony algorithm. The lowest-lying structures of Gd2Sin− (n = 3–12) are all exohedral structures with two Gd atoms face-capping the Sin frameworks. Results show that the pentagonal bipyramid (PB) shape is the basic framework for the nascent growth process of the present clusters, and forming the PB structure begins with n = 5. The Gd2Si5− is the potential magic cluster due to significantly higher average binding energies and second order difference energies, which can also be further verified by localized orbital locator and adaptive natural density partitioning methods. Moreover, the localized f-electron can be observed by natural atomic orbital analysis, implying that these electrons are not affected by the pure silicon atoms and scarcely participate in bonding. Hence, the implantation of these elements into a silicon substrate could present a potential alternative strategy for designing and synthesizing rare earth magnetic silicon-based materials. [ABSTRACT FROM AUTHOR]

Pyrophyllite is an important layered phyllosilicate material that is used in many fields due to its beneficial physicochemical and mechanical properties. Due to the presence of multiple defects in pyrophyllite, an in-depth investigation was conducted using density functional theory to explore the effects of Na(I), K(I), Mg(II), Ca(II) and Fe(II) doping on the atomic structure, electronic properties and mechanical characteristics of pyrophyllite. The results demonstrated that, among the studied defects, K(I) doping had the most pronounced effects on the lattice constants and bonding lengths of pyrophyllite, while the least significant effects were observed in the case of Fe(II) doping. Moreover, the partial and total densities of states and band structures of the five kinds of doped pyrophyllite also changed significantly due to the redistribution of electrons. Finally, the elastic constants of the doped pyrophyllite were lower than that of the undoped pyrophyllite. Doping with Na(I), K(I), Mg(II), Ca(II) and Fe(II) reduced the deformation resistance, stiffness and elastic wave velocity but increased the degree of anisotropy in pyrophyllite. The observed effects on the mechanical properties of pyrophyllite followed the order: Mg(II) > Fe(II) > Ca(II) >K(I) > Na(I). [ABSTRACT FROM AUTHOR]

In this paper, the electronic and piezoelectric properties of two-dimensional Janus CrXY (X/ Y = S, Se,Te) systems were investigated. The results show that the Janus CrXY systems are excellent semiconductor materials and the band gap widths of Janus CrXY range from 0. 27 eV to 0. 83 eV. The strain regulation in the x-axis direction has a great influence on the band gap, while the strain regulation in the z-axis direction has little influence on the band gap, indicating that the electronic properties of the system have good stability in the z-axis direction. The piezoelectric properties of the system were studied by density generalized perturbation method, the results show that all three materials have large out-of-plane piezoelectric coefficients d33, especially, the d33 of CrSeTe reaches 56. 89 pm/ V, which is about ten times that of the common piezoelectric material AlN (d33 = 5. 60 pm/ V). This research provides theoretical support for the practical application of two-dimensional Janus CrXY systems in the field of flexible and intelligent nanomaterials. [ABSTRACT FROM AUTHOR]

Ca-SiO2 compounds compromise one of the most common series of oxide particles in liquid steels, which could significantly affect the service performance of the steels as crack initiation sites. However, the structural, electronic, and mechanical properties of the compounds in Ca-SiO2 system are still not fully clarified due to the difficulties in the experiments. In this study, a thorough investigation of these properties of Ca-SiO2 compound particles in steels was conducted based on first-principles density functional theory. Corresponding phases were determined by thermodynamic calculation, including gamma dicalcium silicate (γ-C2S), alpha-prime (L) dicalcium silicate (α′L-C2S), alpha-prime (H) dicalcium silicate (α′L-C2S), alpha dicalcium silicate (α-C2S), rankinite (C3S2), hatrurite (C3S), wollastonite (CS), and pseudowollastonite (Ps-CS). The results showed that the calculated crystal structures of the eight phases agree well with the experimental results. All the eight phases are stable according to the calculated formation energies, and γ-C2S is the most stable. O atom contributes the most to the reactivity of these phases. The Young's modulus of the eight phases is in the range of 100.63–132.04 GPa. Poisson's ratio is in the range of 0.249–0.281. This study provided further understanding concerning the Ca-SiO2 compound particles in steels and fulfilled the corresponding property database, paving the way for inclusion engineering and design in terms of fracture-resistant steels. [ABSTRACT FROM AUTHOR]

The electronic and optical properties of three types of aluminum phosphide bilayers are examined using density functional theory. The results indicate that they all possess proper direct gaps, which exhibit a rich variety of behaviors depending on the strain. The band gaps of these aluminum phosphide bilayers could be easily tuned in the energy range from 0 eV to 1.9 eV under a wide range of biaxial strain. Additionally, band gap transitions between direct and indirect types are found when the external strain applied on them is changed from −12% to 12%. In addition, it was found that these AlP bilayers show strong light-harvesting ability for the ultraviolet light range of the solar spectrum (400–100 nm). The results obtained here indicate that these aluminum phosphide bilayers may have significant potential applications in future nanoelectric fields. [ABSTRACT FROM AUTHOR]

The structural evolution, electronic property and spectral analysis of YGenq (n = 4–20, q = 0, −1) has been examined under the framework of density functional theory combined with the Artificial Bees Colony and the Saunders 'Kick' algorithm. The global minimum structure of the YGen- cluster is recognised by contrasting the simulated and measured photoelectron spectra (PES). Average binding energies, second difference energies, highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gaps are shown as size change and display abnormal stability at n = 16. Natural population analysis (NPA) shows the charge transfer from Ge to Y atom is 4.62 e in YGe16-, forming ionic bonds. HOMO–LUMO orbitals are mainly composed of Ge atoms. Electron localisation function (ELF) reveals the electrostatic force between Y and Ge atoms and the covalent interaction between each two Ge atoms, which is in accordance with the bond analysis. The current work shows that YGe16- is viewed as a promising building block for rare earth-doped semiconductor materials. [ABSTRACT FROM AUTHOR]

The growth behavior, stability, electronic and magnetic properties of the Gd2Sin− (n = 3–12) clusters are reported, which are investigated using density functional theory calculations combined with the Saunders ‘Kick’ and the Artificial Bee Colony algorithm. The lowest-lying structures of Gd2Sin− (n = 3–12) are all exohedral structures with two Gd atoms face-capping the Sin frameworks. Results show that the pentagonal bipyramid (PB) shape is the basic framework for the nascent growth process of the present clusters, and forming the PB structure begins with n = 5. The Gd2Si5− is the potential magic cluster due to significantly higher average binding energies and second order difference energies, which can also be further verified by localized orbital locator and adaptive natural density partitioning methods. Moreover, the localized f-electron can be observed by natural atomic orbital analysis, implying that these electrons are not affected by the pure silicon atoms and scarcely participate in bonding. Hence, the implantation of these elements into a silicon substrate could present a potential alternative strategy for designing and synthesizing rare earth magnetic silicon-based materials.

• The M 12 Li− nanoclusters exhibit significant absorption capabilities in the ultraviolet and near-ultraviolet regions. • Li atom significantly modifies electron transfer and distribution within the host structures, thereby enhancing their symmetry and stability. • There exists a weak interaction between dopant and host atoms, while significant attractive effects and spatial hindrance exist among the host atoms. This paper investigates the stable configurations, electronic structures, and optical absorption properties of exohedral doped clusters M 12 Li− (M = Al, Ga, In) using first-principles calculation method. Doping with one Li atom enhances the stability of the bare clusters by positioning them on the outer surface of the ground-state structures. The analysis of ultraviolet-visible absorption spectra demonstrates enhanced absorption of ultraviolet light, providing theoretical insights into optical properties. The natural population analysis reveals that Li atom and the central host atom are the primary donors and acceptors of electron transfer, respectively. Furthermore, the results of the atoms-in-molecules theory and the interaction region indicator suggest there is a significant van der Waals interaction between Li and the central atom in the ground-state isomer, while there exists significant attractive effects and steric hindrance among host atoms. [Display omitted] The stable configurations, BCPs distribution, regional distribution of interatomic interactions and UV–vis absorption spectra of M 12 Li− (M = Al, Ga and In) clusters. [ABSTRACT FROM AUTHOR]

Introducing Sn atoms induces structural transformation of ZnIn 2 S 4 (ZIS) from 3D microspheres to 2D ultrathin nanosheets. This process leads to reduction in band gap, elevation in carrier concentration, and activation of inert basal plane. Such an ingenious triple-benefit approach involving microstructure optimization, electronic property modulation and active site modification, brings about significant enhancement in photocatalytic H 2 evolution activity of ZIS. [Display omitted] • Ultrathin Sn-ZIS nanosheets are prepared via a facile one-step hydrothermal process without surfactant. • DFT calculations and XAFS studies demonstrate the substitution of Zn atoms on ZIS surface layer by Sn atoms. • The morphology, electronic structure, and active site of ZIS can be simultaneously modulated through Sn atom doping. • The photocatalytic HER activity of Sn-ZIS is 6.7 and 3.5 times that of pure ZIS and Pt@ZIS, respectively. To overcome the high cost and complex preparation of cocatalysts in photocatalytic H₂ production, this study pioneers a triple-benefit strategy in visible-light-absorbing semiconductors through microstructure optimization, electronic property modulation, and active site modification in two-dimensional (2D) hexagonal ZnIn₂S₄ (ZIS) via Sn atom doping. Facilely synthesized through a one-step hydrothermal method without surfactants, 4–6 nm thick Sn-doped ZIS nanosheets exhibit reduced charge recombination by preventing excessive self-assembly and aggregation. Density Functional Theory (DFT) and X-ray Absorption Fine Structure (XAFS) confirm Sn's substitution for Zn on (0 0 1) surface, shifting the Fermi level into the conduction band to facilitate electron migration and charge separation. This adjustment also modulates the electronic properties of adjacent S atoms, triggering the inert basal plane for an enhanced H₂ evolution reaction kinetics. Consequently, Sn-ZIS achieves a H₂ evolution rate of 62.18 μmol h−1 under visible light, significantly outperforming pure ZIS and Pt@ZIS by 6.7 and 3.5 times, respectively. [ABSTRACT FROM AUTHOR]

• The ground state structure of MSn 9 − clusters (M = Sc , Y, La) is determined. • Ab initio molecular dynamics explain the thermal stability of the ScSn 9 − cluster. • Various bonding analyses are used to explain the reasons for stability. • The gauge-including magnetically induced currents visualizes the aromaticity. Doping rare earth elements into clusters can significantly improve the performance and application value of the materials. The structure, bonding properties, stability, and aromaticity of MSn 9 − (M = Sc , Y, La) have been investigated using density-functional theory. The global minimum structure of these clusters is determined to be the addition of a triangle to the vertex position of a pentagonal bipyramid. Ab initio molecular dynamics simulations are used to demonstrate the thermal stability of the structure. Bonding analyses indicate the presence of ionic bonding and covalent bonding. Iso-chemical shielding surfaces and the gauge-including magnetically induced currents indicate that MSn 9 − clusters are significantly aromatic. This study provides a comprehensive understanding of tin-based nanomaterials, which is important for their design and synthesis. Integrating AIMD simulations with diverse bonding analyses elucidates the stability of ScSn 9 − clusters, while revealing their aromaticity through visualization using GIMIC. [Display omitted] [ABSTRACT FROM AUTHOR]

Graphyne is a new carbon material with excellent electrical conductivity. It is a research hotspot that using graphyne as polymer filler to enhance the thermal conductivity of composite materials. In this study, the structure, electronic properties, and thermal conductivity of graphyne (GY), polypyrrole (PPy), and graphyne/polypyrrole (GY/PPy) composite materials are studied using density functional theory (DFT), molecular dynamics simulation (MD), and nonequilibrium molecular dynamics simulation (NEMD). It is found that graphyne with approximate aspect ratio has better electronic conductivity. The thermal conductivity of GY/PPy composites with different mass fractions is studied by NEMD. The results show that when 7‐GY‐2 is 20%, the thermal conductivity of GY/PPy composite is about 90% higher than that of pure PPy. In order to further study the interaction of GY/PPy, the electronic properties of the local configuration (GY‐PPy) of the composite are studied. The results show that the strong interaction between graphyne and polypyrrole improves the conductivity of GY‐PPy. This study provides some research ideas and theoretical exploration for improving the electrical conductivity and thermal conductivity of polymer doped with graphyne. [ABSTRACT FROM AUTHOR]

We use first‐principles‐based density functional theory (DFT) calculations to investigate the structural, elastic, and electronic properties of various pristine and oxygen (O)‐functionalized double transition metal (DTM) MXenes with general formulas of M2′M′′C2 and M2′M′′C2O2, where M′ = Mo, Cr and M′′ = Ti, V, Nb, Ta. The dynamic stability of the DTM MXenes are assessed and elastic stiffness constants (Cij) are used to investigate the mechanical stability and properties of the compositions. The calculated elastic properties of the pristine Mo‐based MXenes are found to be superior compared to Cr‐based compounds. Furthermore, the O‐functionalized MXenes exhibit improved in‐plane elastic constants, Young's moduli, and shear moduli compared to their pristine counterpart. We observe that the hybridization of the energy states results in stronger covalent interactions as such increased elastic properties for the M2′M′′C2O2 MXenes. Ashby plot clearly demonstrates superior materials properties of O‐functionalized Mo‐based DTM MXenes compared to other commonly known two‐dimensional materials. All the MXenes exhibit metallic character evident from the density of states (DOS) calculations. Additionally, the work functions are studied and the calculated values are higher in the case of O‐functionalized MXenes. Overall, this work will be a guide for future investigations on the mechanical properties of DTM MXenes for their targeted applications in structural nanocomposites. [ABSTRACT FROM AUTHOR]

Doping is known as an effective approach to extend the knowledge of structures and properties of clusters. Herein, Ge-doped boron clusters and their anions GeBn0/− with n = 6–20 are systematically investigated by using a spin-polarized density functional theory method to understand their structural evolution and electronic properties. The lowest-energy structures of GeBn and GeBn− clusters are globally searched with genetic algorithm. The doping of a Ge atom has significantly affected the growth behaviors of GeBn0/− clusters, leading to a structural evolution from three-dimensional configuration with a hypercoordinated Ge atom to planar or qusi-planar geometry and finally endohedral cage, in which Ge atom prefers the peripheral site or off-center position. Relative stability analysis identifies that GeB8, GeB10, GeB18, GeB7−, GeB9−, and GeB17− are magic clusters. The magnetic moments of GeBn and GeBn− clusters exhibit an evident odd–even oscillation behavior with cluster size, which is closely related to the interaction between the electronic states of Ge and B atoms. The simulated photoelectron spectra for GeBn− clusters can provide a valuable guidance for further experimental and theoretical research. [ABSTRACT FROM AUTHOR]

The electromagnetic and electronic properties of six atomic terminations CrCr-ScFe-T, ZrSb-ScSn-T, CrCr-ScSn-B, ZrSb-ScFe-B, CrCr-ScFe-V, and ZrSb-ScSn-V in complete Heusler alloy Cr2 ZrSb/Sc2 FeSn (100) heterojunction were systematically studied by first-principles calculation based on density functional theory. The results show that the interactions between the interface atoms causes the unevenness of the interface atomic layer, which leads to the increase of the mechanical mismatch rate of the interface layer. Compared with the high spin polarization in the bulk, the spin polarization of the heterojunction is destroyed to varying degrees. Fortunately, the termination ZrSb-ScFe-B retains a high spin polarization value and has a tunnel magnetoresistance of 429.29% at low temperature according to the Julliere model, indicating its potential application prospects in spintronic devices. [ABSTRACT FROM AUTHOR]

Defect and doping are effective methods to modulate the physical and chemical properties of materials. In this report, the structural stability, electronic properties, and quantum capacitance (Cdiff) of Zr2CO2 MXene are investigated by the introduction of Si, Ge, Sn, N, B, S, and F atoms. The doping of F, N, and S atoms makes the system undergo the semiconductor‐to‐conductor transition, while the doping of Si, Ge, and Sn atoms maintains the semiconductor characteristics. The B‐doped system can be used as cathode materials, while the systems doped by S, F, N, Sn atoms are promising anode materials of asymmetric supercapacitors, especially for the S‐doped system. The effect of temperature on Cdiff is further explored. The result indicates that the maximum Cdiff of the studied systems gradually decreases with the increasing temperature. Our investigation can provide useful theoretical basis for designing and developing the ideal electrode materials for supercapacitors. [ABSTRACT FROM AUTHOR]

The electronic, magnetic, and optical properties of PtcoBi half-Heusler compound [001] surfaces and its bulk state have been investigated in the framework of density functional theory using GGa approximation. the half-metallic behaviors of CoBiterm, CoPt-term and PtBi-term decrease with respect to its bulk state. the spin polarization at the Fermi level is 73.2% for the bulk state, and it is -64.4% and -64.1% for the coBi-term and PtBi-term, respectively while less polarization has been observed for the coPt-term. all terminations have given almost similar optical responses to light. Plasmon oscillations for the terminations occur in the range of 12.5 to 14.5 eV (21 to 22 eV) along xx (zz), and it occurs at 23 eV for the bulk state. the refractive index for the bulk and all three terminations is very high in the infrared and visible areas, meaning a very strong metallic trend in these compounds. the phenomenon of super-luminance occurs for the incident light with energy exceeding 5.5 eV for all three terminations, and it occurs in the range of 10 eV for the bulk mode. these terminations show transparent behavior after the energy of 10 eV. [ABSTRACT FROM AUTHOR]

The structural, electronic and optical properties of Mg single doped, N single doped and different concentrations Mg-N co-doped β-Ga2O3 were studied via the first-principles calculation based on density function theory. This work aims to improve the effect of p-type β-Ga2O3 doping. Five models were built including Mg single doped, N-single doped, 1 Mg-N doped, 2 Mg-N doped and 3 Mg-N doped β-Ga2 O3 . Among them, the model of 3 Mg-N doped β-Ga2O3 shows the most stable structure than other doped systems. In attention to, the bandgap of 3 Mg-N doped β-Ga2 O3 material is the smallest. And occupied states contributed by N 2p and Mg 3s inhibit the formation of oxygen vacancies, which increases the concentration of holes. Thus, 3 Mg-N doped β-Ga2 O3 system displays excellent p-type feature. Adsorption peak is obvious red-shift in 3 Mg-N doped system, and the adsorption coefficient is bigger at solar-blind region, which is ascribed to the interband electron transition from the Ga 4s, Ga 4p, Mg 3s of conduct band to O 2p, N 2p of valence band. This work will provide a theoretical guide for the study and application of p-type β-Ga2 O3 materials. [ABSTRACT FROM AUTHOR]

The structural, electronic and optical properties of Mg single doped, N single doped and different concentrations Mg-N co-doped β-Ga2O3 were studied via the first-principles calculation based on density function theory. This work aims to improve the effect of p-type β-Ga2O3 doping. Five models were built including Mg single doped, N-single doped, 1 Mg-N doped, 2 Mg-N doped and 3 Mg-N doped β-Ga2 O3 . Among them, the model of 3 Mg-N doped β-Ga2O3 shows the most stable structure than other doped systems. In attention to, the bandgap of 3 Mg-N doped β-Ga2 O3 material is the smallest. And occupied states contributed by N 2p and Mg 3s inhibit the formation of oxygen vacancies, which increases the concentration of holes. Thus, 3 Mg-N doped β-Ga2 O3 system displays excellent p-type feature. Adsorption peak is obvious red-shift in 3 Mg-N doped system, and the adsorption coefficient is bigger at solar-blind region, which is ascribed to the interband electron transition from the Ga 4s, Ga 4p, Mg 3s of conduct band to O 2p, N 2p of valence band. This work will provide a theoretical guide for the study and application of p-type β-Ga2 O3 materials. [ABSTRACT FROM AUTHOR]

On the basis of known structures of β-GeTe bulk and the derived monolayer, we proposed a series of structural analogues MXs (M = Ge, Sn; X = S, Se, Te) with an intrinsic built-in electric field via a substitution strategy. Using first-principles calculations, we demonstrated that these MX monolayers and bulks are thermodynamically, dynamically and mechanically stable, and the stabilities of bulks are more robust than the monolayer counterparts. Electronic calculations showed that the monolayers have large band gaps ranging from 2.38 to 3.27 eV while the bulks have pronounced small band gaps ranging from 0.06 to 0.78 eV. The calculated piezoelectric coefficients d11 for the MX monolayers are in the range from 6.6 to 10.9 pm/V. Strikingly, the calculated d33 for the MX bulks are as high as 40.3–213.7 pm/V. By correlating atomic polarizability, atomic mass, relative ion motion, Bader charge and lattice parameters, we proposed an empirical model to estimate the piezoelectric coefficients for the two-dimensional (2D) MXs, where a nice match between the estimated ones and the calculated ones was found. The versatile electronic properties and large piezoelectric coefficients endow MXs a broad prospect of application in optoelectronic and piezoelectric devices, and the revealed underlying mechanisms offer valuable guidelines for seeking novel piezoelectrics. [ABSTRACT FROM AUTHOR]

Abstract To improve the photocatalytic performance of pristine photocatalysts, element doping, construction of composites and fabrication of novel nanostructures are recognized as universal modification methods. These methods have been experimentally verified to be effective in manifold photocatalytic application over various photocatalysts. Density functional theory (DFT) calculation is a powerful and fundamental tool to pinpoint the intrinsic mechanism of the enhanced photocatalytic activity. And it holds the degree of precision ranging from atoms, molecules to unit cells. Herein, recent DFT calculation research progress of modified s‐triazine‐based graphitic carbon nitride (g–C3N4) systems as photocatalysts is summarized. To specify, we collected information of doping site, formation energy, geometric, and electronic properties. We also discussed the synergistic effect of work function, Fermi level and band edge position on the built‐in electric field, transfer route of photogenerated charge carriers and photocatalytic mechanism (traditional type II or direct Z‐scheme heterostructure). Moreover, we analyzed the geometric configuration, band structure, and stability of g–C3N4 nanocluster, nanoribbon, and nanotube. Finally, future perspective in the further theoretical revelation of g–C3N4‐based photocatalysts is proposed.

Density functional theory (DFT) studies were performed to evaluate the adsorption behavior and electronic response of (4,4) carbon nanotubes (CNTs) to the organophosphorus nerve agents 3,3-dimethylbutan-2-yl methyl phosphono fluoridate (Soman), pinacolyl methyl phosphonate (SOS), diethyl fluorophosphates (SAS-F) and diethyl chlorophosphate (SAS-Cl). The calculations were performed using the triple numerical plus polarization (TNP) as the basis set with an orbital cutoff of 4.5 Å. The electronic exchange and correlation effects were analyzed by generalized gradient approximation (GGA) with the BLYP parameterization. The studied systems were fully optimized and adsorption energy (Ead), interaction distances, geometric and electronic structures were investigated. According to the obtained relatively high Ead, it was shown that Soman, SOS, SAS-Cl and SAS-F more likely to be absorbed on the CNTs surfaces, introducing an interesting candidate for chemisorption of the nerve agent gas molecules. As a result, the order of increasing of the Ead values of the studied systems were |Ead SAS-F/CNT| > |Ead SAS-Cl/CNT| > |Ead SOS/CNT| > |Ead Soman/CNT| systems. The calculated partial density of states (PDOS) of the adsorption systems confirmed the strong electrons interaction between the nerve agent molecules and the CNTs surfaces. The obtained results indicated the potential application of CNTs in the design and fabrication of protective low-cost gas filters against toxic odorless nerve agent gases. [ABSTRACT FROM AUTHOR]

The electronic and optical properties of Ni-doped Bi4O5I2 systems were investigated via first-principle calculations. For the pristine Bi4O5I2, the band gap was calculated to be 2.17 eV, which was close to the experimental report. When the concentration of Ni increased, the band gap obviously decreased, which was ascribed to the introduction of Ni 3d doping states in the forbidden band gap. Based on the dielectric function analysis, the variations of the optical properties mainly took place in the visible light range, and the additional peak in the visible light range originated from the electron transition between the Ni 3d and Bi 6p states. Accordingly, the light absorption in the visible light range obviously increased, which was favorable for photocatalytic applications.

The structural, electronic and optical properties of BexZn1−xO alloys were studied using the density functional theory and Hubbard-U method. Uo;p = 10.2 eV for O 2p and UZn;d = 1.4 eV for Zn 3d were adopted as the Hubbard U values. For BexZn1−xO alloys, the lattice constants a and c decrease linearly as Be concentration increases, the bandgap increases with a large bowing parameter of 6.95 eV, the formation enthalpies have the maximum value with Be concentration at 0.625, corresponding to the possible Be concentration to form phase separation. These calculations comply well with the experimental and other theoretical results. Furthermore, optical properties, such as dielectric function ∈(ω), reflectivity R(ω), absorption coefficient α(ω), were calculated and discussed for BexZn1−xO alloys with the incident photon energy ranging from 0 eV to 30 eV. [ABSTRACT FROM AUTHOR]

The geometrical structures, stability and electronic properties of PtmIrn and PtmIrnNO (m + n = 8 − 1 0) clusters have been studied by using density functional theory (DFT). Simple cube evolution pattern is revealed for Ir 8 − 1 0 and Ir-rich clusters. The curve of the second-order energy difference of PtnIr (9 − n) clusters shows the evident even–odd oscillations, indicating that PtIr8, Pt3Ir6, Pt5Ir4 and Pt7Ir2 clusters are more stable than their neighbors. The minimum excess energies values are seen for Pt7Ir, PtIr8 and Pt2Ir8, which means that these clusters show the stronger mixing tendency. Analysis of magnetic properties shows that the total magnetic moment contributed from Ir and Pt atoms, and the magnetic moment mainly comes from localization of the d orbit electron. All ground-state structures show an adsorption of NO at the top site of the bare cluster via the N atom. In all of the alloy clusters, NO molecule prefers to be adsorbed near the Ir atom site. Fukui function is an accurate predictor of the reactivity on a specific adsorption site in Pt–Ir alloy clusters. [ABSTRACT FROM AUTHOR]

The stable configurations, electronic structures and catalytic activities of single-atom metal catalyst anchored silicon-doped graphene sheets (3Si-graphene-M, M = Ni and Pd) are investigated by using density functional theory calculations. Firstly, the adsorption stability and electronic property of different gas reactants (O2, CO, 2CO, CO/O2) on 3Si-graphene-M substrates are comparably analysed. It is found that the coadsorption of O2/CO or 2CO molecules is more stable than that of the isolated O2 or CO molecule. Meanwhile, the adsorbed species on 3Si-graphene-Ni sheet are more stable than those on the 3Si-graphene-Pd sheet. Secondly, the possible CO oxidation reactions on the 3Si-graphene-M are investigated through Eley–Rideal (ER), Langmuir–Hinshelwood (LH) and new termolecular Eley–Rideal (TER) mechanisms. Compared with the LH and TER mechanisms, the interaction between 2CO and O2 molecules (O2 + CO → CO3, CO3 + CO → 2CO2) through ER reactions (< 0.2 eV) are an energetically more favourable. These results provide important reference for understanding the catalytic mechanism for CO oxidation on graphene-based catalyst. [ABSTRACT FROM AUTHOR]

Structural, electronic and magnetic properties of the neutral and ionic Nin−1X (X = C, Si, Ge, Sn, Pb; n = 19–23) clusters have been investigated using the density functional theory calculations with the PBE exchange–correlation energy functional. The calculations have shown that for the most stable structures of all Nin−1X clusters, only Si atom prefers to locate in the center position, while for the other atoms, the impurity usually adopts the surface position. Based on the most stable Nin−1X clusters, the properties including binding energy per atom, embedding energy, charge transfer, ionization potentials, electron affinities and especially magnetic properties have been discussed. [ABSTRACT FROM AUTHOR]

Hematite (Fe 2 O 3) is a prevalent mineral known for its utility as an optoelectronic and photocatalytic material. It boasts abundant reserves, cost-effectiveness, and widespread use in optoelectronic and photocatalytic applications. Recently, the discovery of Fe 2 O 3 monolayers has expanded its potential as a promising material in the same domains. The foundational attributes for its applications are rooted in its electronic and optical properties. In this study, we used density functional theory, specifically the Meta -GGA + U approach, to explore the electronic and optical properties of monolayer Fe 2 O 3 doped with Mn and subject to Mn adsorption. Additionally, we examine the properties of Mn-doped Fe 2 O 3 monolayers containing intrinsic vacancies. Our computational analysis reveals that the incorporation of Mn as a dopant, along with adsorption configuration, leads to a reduction in the band gap of the Fe 2 O 3 monolayer. This effect is further observed in Mn-doped Fe 2 O 3 monolayers containing intrinsic vacancies. Notably, the introduction of intrinsic vacancies involving both Fe and O contributes to a decrease in the band gap, concurrently enhancing the optical characteristics of the Fe 2 O 3 monolayer. Remarkably, these alterations induce energy bands and intrinsic vacancies that improve optical properties within the visible and near-UV regions. Our investigation also proposes a potential application (water splitting) for the Fe 2 O 3 monolayer. Through our comprehensive exploration, we not only underscore the promising prospects of Mn-doped and -adsorbed Fe 2 O 3 monolayers in future applications but also catalyze further research endeavors in this domain. • SCAN Meta -GGA plus U method was used to guarantee the accuracy and efficiency of this study. • Mn and intrinsic vacancy were used to modulate the electronic and optical properties in Fe 2 O 3 monolayer. • Mn-adsorbed Fe 2 O 3 and (Fe,Mn) 2 O 3 monolayer with O vacancy performs better in the solar energy region. • Mn modified Fe 2 O 3 monolayer can serve as a potential platform for photoelectric devices, photocatalyst. [ABSTRACT FROM AUTHOR]

Layered crystal Bi2O2Te has recently been found to have high electron mobility and excellent thermoelectric properties for technical applications; however, its other properties are not well studied yet. In this work, the electronic, elastic and optical properties of Bi2O2Te are systematically studied using the density functional method. The results indicate that Bi2O2Te is a narrow band gap semiconductor. The gap is formed by the Te 5p orbital at the top of the valence band and the Bi 6p orbital at the bottom of the conduction band. There are both ionic and covalent interactions within the Bi–O layers, and these layers are linked by the ionic Bi–Te bonds forming the crystal. Bi2O2Te is mechanically stable but anisotropic. It is easy to fracture along the c axis under shear stress. Its shear modulus is far smaller than its bulk modulus, so shape deformation is easier to occur than pure volume change. Its melting point is predicted to be 1284.0 K based on an empirical formula. The calculated refractive index at zero frequency reveals that Bi2O2Te is a negative uniaxial crystal with a birefringence of 0.51, making it a potential tuning material for optical application. The characteristics and origins of other optical properties are also discussed. [ABSTRACT FROM AUTHOR]

Low-dimensional materials cleaved from their high performance topological-insulators-property bulk counterparts are attractive to be investigated. Here, the researched X 2 Te 3 (X = Sb, Bi) single layer materials and their thermodynamical stabilities are proved through our calculations. The indirect band gaps pulse with the high carrier mobilities are also discussed based on first-principle calculations. On basis of the calculation, the low cleavage energies are about 0.34 J m−2 that is comparable with that of graphite, which imply a high possibility to obtain the single layer from exfoliating bulk counterpart. Band gaps are simulated as between 0.65 and 1.31 eV using different functionals, moreover, the band structures with and without SOC effect are all considered. The SOC effect results certify that X 2 Te 3 monolayers are different from their bulk counterparts, they are not topological insulators. The largest electron mobility selected in their impressive carrier mobilites is 27.91×103 cm2V−1S−1 that bears comparison to that of silicene. Moreover, the mechanical properties include Young's moduli and Poisson's ratio are studied too. Meanwhile, the biaxial strain can effectively modify the band gaps. Finally, outstanding visible and near-infrared light absorption abilities mainly from ~400 to around 1400 nm may guide single layer X 2 Te 3 to a promises applications in photovoltaics. The works based on density functional theory to predict a new kind of two dimensional material that called X 2 Te 3 (X = Sb, Bi). • The new 2D materials possess impressive charge mobilities that is comparable with that of silicone, as well as suitable cleavage energies. • The suitable band gaps give it a bright future for micro-electronic device applications. • Different calculation functionals and SOC effect are considered to ensure the correction of our research. • The mechanical property and optical property are also researched while the modification of electronic property under external applied strain for 2D X 2 Te 3 (X = Sb, Bi) is carefully studied. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) materials exhibit unique electronic properties compared with their bulks. A systematical study of new type 2D tetragonal materials of MPn (M = Sc and Y; Pn = P, As and Sb) nanosheets and the corresponding nanoribbons are proposed by density functional theory calculations. Several thermodynamically stable 2D tetragonal structures were firstly determined, and such novel tetragonal structures bilayer MPn(100) exhibit extraordinary Weyl semimetal electronic structures, while monolayer MPn(110) are semiconductors. Moreover, bilayer MPn(100) nanoribbons with zigzag edges show metallic behavior, whereas those with linear edges show semiconducting properties. The band gaps for bilayer MPn(100) nanoribbons with linear edges can be significantly tuned by their widths. The zero-gap semiconducting behaviors of 2D tetragonal MPn nanosheets and the tunable band gaps of 1D MPn nanoribbons provide these MPn nanosheets and nanoribbons with promising applications in nanoscale electronic devices. • Novel 2D tetragonal Group-IIIB Pnictides discovered by DFT calculations. • Bilayer MPn(100) exhibits Weyl semimetal electronic structures. • Bandgaps of MPn nanoribbons can be significantly tuned by widths. [ABSTRACT FROM AUTHOR]

Geometric and electronic properties of nitric oxide adsorption on WmMon (m + n ≤ 6) clusters have been systematically calculated by density functional theory (DFT) at the generalized gradient approximation (GGA) level for ground-state structures. NO molecule prefers top site with nitrogen-end bridging a tungsten atom for W 1 , 2 Mo 1 , 2 , 3 and W3Mo2 clusters. While NO tends to locate on the hollow site for WMo5, W2Mo4 and W3Mo3 clusters, and dissociation of NO molecule happens on W3Mo, N–O bond lengths expand in accordance with the variation of adsorption energy with the increasing number of tungsten atoms, originating from metal → π ∗ back-donation. Electron transfer occurs among 4d state of Mo, 5d state of W, 2p state of N and 2p state of O. [ABSTRACT FROM AUTHOR]

Enhanced optical absorption, generated charge separation and improved carrier mobility suggest that construction of MoSi 2 N 4 /WO 2 vdWH is a good strategy to boost 2D MoSi 2 N 4 ′s nanoelectronic and optoelectronic applications. [Display omitted] • MoSi 2 N 4 /WO 2 vdWH not only is built on primitive cells and but also exhibits small lattice mismatch. • MoSi 2 N 4 /WO 2 vdWH represents a typical type-II band alignment. • In particular, type-II band alignment is rather solid. • MoSi 2 N 4 /WO 2 vdWH can display enhanced absorption abilities. • MoSi 2 N 4 /WO 2 vdWH also can exhibit high electron mobility of 2370 cm2 V−1 s−1. Recently, MoSi 2 N 4 layer, a new species of two-dimensional (2D) materials, has attracted considerable attention. Nanoelectronic and optoelectronic applications are two of the most promising applications of 2D materials. Herein, via density functional theory (DFT) calculations, we proposed a MoSi 2 N 4 /WO 2 van der Waals heterostructure (vdWH) to boost 2D MoSi 2 N 4 ′s nanoelectronic and optoelectronic applications. Primary results are listed below. (a) The MoSi 2 N 4 /WO 2 vdWH has a good dynamical stability, and its formation is an exothermic process. (b) Interestingly, MoSi 2 N 4 /WO 2 vdWH displays a typical type-II band alignment, which is beneficial for the separation of photogenerated electron-hole pairs, but it was missed in MoSi 2 N 4 layer. (c) In particular, its type-II band alignment is independent of its stacking model. (d) In contrast with the electron mobility of 1330 cm2 V−1 s−1 of MoSi 2 N 4 layer, the value of MoSi 2 N 4 /WO 2 vdWH can reach up to 2370 cm2 V−1 s−1. (e) In addition, we also observed that, compared with MoSi 2 N 4 layer, MoSi 2 N 4 /WO 2 vdWH can display enhanced absorption abilities for both visible and ultraviolet lights. These findings manifest that construction of MoSi 2 N 4 /WO 2 vdWH is an effective method to improve MoSi 2 N 4 layer's nanoelectronic and optoelectronic applications. [ABSTRACT FROM AUTHOR]

The adjustable magnetic moments of REGe 6 − clusters increase monotonically. [Display omitted] • The dopant atoms are basically located at the top (or side) of pentagonal bipyramid. • The results of the theoretical study provide theoretical guidance for future experiments in anion photoelectron spectroscopy. • The adjustable magnetic moments of REGe 6 − (RE = Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu) clusters increase monotonically from 0 to 8µ B. • Most regions of the REGe 6 − clusters exhibit strong aromaticity. The geometries, electronic, and magnetic properties in a series of rare-earth (RE) metal atoms (Sc, Y, La, Ce, Pr, Nd, Pm, Sm, and Eu) doped Ge clusters, REGe 6 −, are investigated using density functional theory calculations and the results are compared with experimental literature data. It was found that all REGe 6 − clusters have similar pentagonal bipyramid structures, where the RE atom is located at the top (or side) of the pentagonal bipyramid. Natural population analysis reveals that the electrons always transfer from the RE atom to parent germanium atoms. The spin density and the density of states diagrams visually showed that the magnetic moments increase monotonically from Sc to Eu, which mainly derive from the contribution of the RE atoms. Isochemical shielding surfaces analyses indicate that the most regions of the REGe 6 − clusters (i.e., the pentagonal and the tetragonal ring in REGe 6 −) exhibit strong aromaticity compared with the benzene ring. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Au or Cl adsorption on the 1I-terminated BiOI (0 0 1) surface is investigated. • Au/BiOI and Cl/BiOI systems possess the better utilization of the visible light. • Au-H system shows the best photocatalytic performance and structural stability. Abstract First-principles calculation based on DFT is performed to explore the structural, electronic and optical properties of monatomic Au or Cl adsorption on the bridge and fourfold hollow site of the 1I-terminated BiOI (0 0 1) surface. The results indicate that Au/BiOI and Cl/BiOI adsorption systems not only possess the better structural stability but also exhibit the perfect utilization of the visible light. The range of visible light utilization is broadened after Au or Cl adsorption at the B and H sites thus the photocatalytic performance can be improved. Au adsorption at H site shows the best photocatalytic performance and structural stability. [ABSTRACT FROM AUTHOR]