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In this work, we will investigate structural, electronic, magnetic, and thermodynamic properties using density functional theory (DFT) and the quasi-harmonic Debye model. We consider ferromagnetic (FM) and non-magnetic (NM) states for L2₁ and Hg₂CuTi-type crystal structures. The best stability is obtained for ferromagnetic Rh₂MnGa in a Cu₂MnAl structure with a lattice parameter of 6.07 Å and a total magnetic moment of 4.11${\mu }_B$. The compressive strain range from $-6$% to $+4$% tensile strain maintains the ferromagnetic nature and enhances the magnetic moment up to 4.39${\mu }_B$. The formation energy confirms the inherent stability of Rh₂MnGa. Other important thermodynamic parameters such as the expansion coefficient ($\alpha$), heat capacity ($C_V$), Debye temperature (${\theta }_D$) and Grüneisen constant ($\gamma$) are also estimated in this work.

DFT is used for making first-principles calculations of electronic and optical properties of V₂O₅ in its orthorhombic phase, by employing Augmented Plane Waves$+$local orbital method with Generalized Gradient Approximation and Perdew–Burke–Ernzerhof potential to account for exchange–correlation interactions. The stability of the material is checked through the calculation of cohesive energy and Bader charge analysis is done to find out the electronic charges on different atoms in the unit cell. A DOS gap of about 2.1eV and a direct band gap of about 1.85eV just above the Fermi level is found to occur on using DFT, which is lower than the experimental value of 2.77eV. On using the DFT$+$U method, with $U=4.0$eV for Vanadium, a DOS gap of about 2.8eV and an indirect band gap of about 3.0eV are found to occur, which are closer to the experimental result, showing that the DFT+U method better accounts for electronic properties of V₂O₅. The optical properties, such as dielectric function, reflectivity, absorption coefficient, optical conductivity, refractive index, extinction coefficient and electron energy loss function also investigated for V₂O₅ by using DFT.

In this work, we delve into the investigation of the structural, electronic, and optical properties of Ba₂NbBiS₆ and Ba₂TaSbS₆ chalcogenide-based double perovskites, which are structured in the cubic space group $Fm\bar{3}m$ form. We have performed first-principles calculations using density functional theory (DFT) to study the above properties. The electronic band structure and density of states of this compound have been investigated, and their results show that Ba₂NbBiS₆ and Ba₂TaSbS₆ exhibit a semiconducting nature with an indirect energy gap of 1.680eV and 1.529eV, respectively. Furthermore, an investigation was conducted on the optical properties of the compounds throughout the energy range spanning from 0eV to 55eV. This investigation focused on many parameters, including dielectric functions, optical reflectivity, refractive index, extinction coefficient, optical conductivity, and electron energy loss. The optical data obtained from the calculations reveals that all compounds demonstrate isotropy in optical polarization. Furthermore, it has been noted that our compounds exhibit absorption properties inside the ultraviolet (UV) region. Consequently, these materials hold promise as potential candidates for various applications, such as UV photodetectors, UV light emitters, and power electronics. This is primarily attributed to their inherent absorption limits and the presence of prominent absorption peaks in this spectral range. In brief, chemical mutation techniques have been employed to manipulate the characteristics of double-sulfide perovskites to develop durable and environmentally friendly perovskite materials suitable for solar purposes.

This study provides a thorough analysis of magnesium oxynitride (MgON), employing first-principles calculations to investigate its potential for electronic, thermoelectric, and optical applications. The main objective was to comprehend the fundamental electronic, thermoelectric, and optical parameters of MgON using density functional theory (DFT) calculations. In electronic properties, the density of states (DOS) spectra revealed the significant contribution of Mg-s and O-p states for pristine MgO, while N-p states provide the maximum contributions with overlapping at the Fermi level in nitrogen-containing compositions. The band structure depicted a direct nature for undoped and doped MgO, and the bandgap of compositions was observed to decrease with the increment in nitrogen concentration. The thermoelectric properties of pure and N-doped MgO compositions were evaluated, which showed significant variations with an increase in temperature and doping. Furthermore, the optical properties of MgON were inspected and found to enhance optical conductivity, and absorption coefficient, whereas the refractive index and dielectric constant decrease at specific energy regions for elevated dopant content, which suggests its suitability for optoelectronic applications. Overall, this study reveals the versatility of MgON, making it a potential candidate for advanced electronic, thermoelectric, and optical applications.

This paper presents a simulation of the structural and optoelectronic properties of Scandium Arsenide (ScAs) and Aluminum Arsenide (AlAs) compounds. Theoretical modeling was performed using ab initio first-principles calculations, specifically the density functional theory (DFT), and the Mindlab numerical software. The software used two methods: the full-potential muffin-tin orbital method (FP-LMTO) and the full-potential plane-wave method (FP-LAPW). These two methods are employed to solve the Schrödinger equation. The exchange correlation effects have been computed using two different approximations: the generalized gradient approximation (GGA) and the local density approximation (LDA). Our findings indicate that the zinc blende structure (B3) is the stable phase, while the Wurtzite phase (B4) is metastable for the AlAs compound. On the other hand, the ScAs compound crystallizes in the NaCl phase (B1). The AlAs compounds undergo three phase transitions: $\mathrm{\text{B3}}\to \mathrm{\text{B4}}$, $\mathrm{\text{B3}}\to \mathrm{\text{B2}}$ and $\mathrm{\text{B3}}\to \mathrm{\text{B1}}$. In contrast, ScAs does not undergo any transition. The obtained results for equilibrium energies, lattice parameters and gap energies are in closer agreement with the experimental and theoretical data. The AlAs compound exhibits a semiconducting character, while ScAs exhibits a semi-metallic character. Additionally, the refractive index of these two compounds is similar to that of silicon, which is crucial for their application in photovoltaic cells.

In this paper, we present the implementation of the Density Functional Theory (DFT) method using the Geant4-DNA framework in the Single Instruction Single Data (SISD) mode. Furthermore, this implementation is improved in terms of execution time within the GeantV project with vectorization techniques such as Single Instruction Multiple Data (SIMD). Within this framework, a set of SIMD strategies in molecular calculation algorithms such as one-electron operators, two-electron operator, quadrature grids, and functionals, was implemented using the VecCore library. The applications developed in this work implement two DFT functionals, the Local Density Approximation (LDA) and the General Gradient Approximation (GGA), to approximate the molecular ground-state energies of small molecules and amino acids. To assess the performance of the implementations, a standard test simulation was performed in multiple CPU platforms. The SIMD vectorization strategy significantly accelerates DFT calculations, leading to time ratios ranging from 1.6 to 5.4 in either individual steps or entire implementations when compared with the scalar process within Geant4.

The influence of incorporating iron on the electronic structure, magnetic and optical properties of zigzag (10,0) boron nitride nanotubes (BNNTs) was investigated using first-principles calculations. The structures were incorporated with Fe according to B1$-x$Fe xN at various (x) contents (0.10, 0.20 and 0.30). Our calculations exhibited that adding additional Fe atoms reduced the energy gap of the structure. Incorporating more iron atoms creates additional sharp peaks within Fermi levels that come from the contribution of Fe-3d states. Doping with (Fe) also introduced magnetic moments in the BNNT structure. The optical parameters of the Fe-incorporated boron nitride nanotube are calculated. The real part of the dielectric function of pristine BNNT started to increase up to the middle of the UV region and then rapidly decreased between the wavelength range of 310–390 nm. Also, the pure boron nitride nanotube has no absorption in the visible light range and only detects UV radiation. The optical calculations showed that incorporating Fe shifted the absorption peaks of BNNTs into risky UV radiations, which helps researchers develop a vision for controlling and developing advanced materials for various electronic applications.

Investigation electron transport via molecular nanoscale junctions is one of the fundamental steps in developing improved high-performance thermoelectric materials for cooling and converting waste heat into electricity. Density functional theory (DFT) and non-equivalent Green’s function are applied to investigate the electric and thermoelectric properties of Fullerene $({\text{C}}_{60})$ doped with three metalloid ions from the periodic table. The M@C${}_{60}$ (M = P, As and Se) systems have two types of electrodes (gold and graphene). The results show that the electric conductance of G with gold leads is higher than the conductance attached to the graphene leads. Also, ${\text{C}}_{60}$ doped by Se is the best compared with P and as for both gold and graphene electrodes. Moreover, the calculations of HOMO-LUMO resonance shifted toward the high energy (low wavelength) in order $\mathrm{\text{Se}}>\mathrm{\text{P}}>\mathrm{\text{As}}$ due to the electronegativity, which is ordering $\mathrm{\text{Se}}>\mathrm{\text{P}}>\mathrm{\text{As}}$, with the Fano-resonance fixed around E–E${}_F=0$. Meanwhile, the value of Seebeck coefficient S for graphene leads is higher than S linked to the gold lead. Also, the merit figure for ZT and thermal electricity has been investigated.

We carry out a computational investigation of the alkaline-earth (Ba)-based silicon and carbon oxide perovskites (BaSiO₃ and ${\text{BaCO}}_3)$ with the aim of their potential in wide-ranged applications. Exploiting the density functional theory (DFT) coded within Wien2K, we study the structural, electronic, and optical properties of these compounds. Modified Becke–Johnson (mBJ) potential, the established approach for obtaining accurate results, is employed to carry out the electronic investigation. With a simple cubic structure, we find that these materials exhibit metallic properties, as revealed by their mutually consistent band structure profiles and density of states. The valence band minima and conduction band maxima overlap at the $\mathrm{\Gamma }$ point in the band structure. We analyze the total and partial density of states to determine the proportional contributions of each atom, both in total and within individual subshells, such as the $p$- and $d$-subshells in the case of the partial density of states. In our investigation of the optical properties of these materials over the energy range of 0–14eV, we find that they effectively absorb ultraviolet and visible (UV–Vis) light. This shows that the studied compounds have potential applications in luminescence and devices requiring absorption in the UV range. BaCO₃ demonstrates more absorption spectra than the BaSiO₃ versus photon energy ranging from 1.7 to 3.1eV (visible range), suggesting that the BaCO₃ is more suitable than BaSiO₃ for applications that require UV absorption such as sunscreen, UV-blocking films, photodetectors and UV sensors and medical applications. We also find that BaCO₃ with a higher refractive index (11) compared to BaSiO₃ (4.2), is denser than BaSiO₃, resulting in a lower speed of light within the material. This suggests that BaCO₃ is more promising than BaSiO₃ for applications in eyewear. We infer that this study will guide and stimulate experimental investigations into these materials, given their potential for various applications.

Heme-type porphyrins can become distorted depending on their environment, altering their chemical and electronic properties. While trends have been established for several ruffle-distorted porphyrins, their research on synthetic models of heme-type porphyrins is limited. We identified a dynamic process on the ruffled porphyrin bis(2-methylpyridinato)iron(III)-Protoporphyrin-IX (2) that does not exist in bis(pyridinato)iron(III)-Protoporphyrin-IX (1). We modeled these molecules as {OMP(2-CH₃Py)₂Fe}${}^{+}$ and {[OMP](Py)₂Fe}${}^{+}$ respectively. Geometry optimization using density functional theory (DFT) suggests the ruffled conformation of 2 (angle x̄ of $-29.7^{\circ }$) and the planar conformation of 1. The calculated electron affinity and ionization potential vary depending upon ruffling. The calculated 0.253 eV difference in electron affinity and the 0.223 eV in ionization potential indicate that the reduction of the planar structure has a higher energy requirement than the ruffled-distorted structure but has a lower energy requirement for its oxidation. We found that these energy differences are not solely attributed to the distortion of the macrocycle. The difference is linked to the interaction between the d${}_{\text{x}\text{y}}$ orbital and the HOMO-1 3a${}_{2\text{u}}$, allowed by symmetry when a porphyrin ring has a ruffled conformation stabilizing the frontier orbitals, thus making the oxidation process have a higher energy barrier. On the other hand, the reduction process is facilitated by the interaction of metal d_π orbitals with the porphyrin 4e. These highlight the distinct differences between the ruffled and the planar conformations.

The advancement of science and technology is essential for the progress of nanotechnology, which plays a pivotal role in the development of miniaturized and energy-efficient devices. This investigation delves into the As-doped structures within one-dimensional germanene nanoribbons. Utilizing Density Functional Theory (DFT) in conjunction with the Vienna Ab initio Simulation Package (VASP), the study explores the electro-optical properties of the material influenced by As doping, examining both the doping position and density’s effects. Results indicate As significantly alters the electro-optical characteristics, with the semiconductor structure transitioning to metals in top and valley configurations, while meta and para configurations retain semiconductor properties with an indirect band gap. Analysis of bond length, bond angle, magnetism, formation energy and charge density difference elucidates As’ impact on hexagonal structure stability and electromagnetism properties of the system. Furthermore, a comprehensive investigation of optical properties not only offers insights into material systems but also highlights potential applications in optical communications and sensing technologies.

In this paper, we investigated the structural, elastic, topological-electronic properties as well as optical properties of two half-Heusler (HH) heavy fermions-based compounds: HoPtBi and HoPdBi. We accomplished our calculations in the framework of density functional theory (DFT), based on the full potential linearized augmented plane wave (FP-LAPW). Both compounds are antiferromagnetic (AFM) type-II as reported by experimental data so we carried out our study in the AFM type-II configuration. Considering the spin-orbit coupling, we found that the hydrostatic pressure leads to a phase transition from the trivial semimetal to the topological semimetal (TSM) because of band inversion for HoPdBi with no apparent effect of hydrostatic pressure on the topological phase for HoPtBi. We also studied their optical properties, without and with hydrostatic pressure. The first peak in reflectivity, absorption, optical conductivity spectra and energy loss factor are strongly influenced by the hydrostatic pressure. Both compounds exhibit a considerable first absorption peak in the visible and ultraviolet ranges and they are best candidates for solar cells considered essential in renewable energy.

The ground state geometry of the nickel derivative [Daiquiris(nicotinamide-jN1) nickel(II)]-fumarato-K2O1:O4 has been optimized and is being led toward its quantum chemical analysis in this paper. For more accuracy, we used the 6-311$++$G (d, p) basis set for C, H, N, and O atoms and the LAN2DZ basis set for Ni. The calculated and experimental infrared (IR) spectra for the title molecule are well correlated, and the correlation factor $R^2=0.9947$ shows that the method effectively interprets the molecule’s IR spectra. The electronic properties such as highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies and associated energy gap have been calculated by Time-Dependent Density Functional Theory (TD-DFT) approach. The natural bond orbital (NBO) analysis of the molecule describes how interatomic charge transfer results in the formation of bonding–nonbonding interactions. The experimental and calculated Ultraviolet visible (UV-Vis) spectra are compared. We anticipate our work will inspire fresh approaches to the title molecule’s ongoing research.

Monolayer Molybdenum disulfide (ML-MoS₂) has emerged as a promising two-dimensional (2D) material with unique electronic, optical and mechanical properties. In this paper, with the aid of first-principles calculations, we explain the optimization of the structural and computational parameters and discuss the electrical properties of ML-MoS₂. The electronic properties were studied comparatively with and without considering the spin-orbit coupling (SOC) effect that shows, ML-MoS₂ has a direct bandgap. A decrease in bandgap energy by 100 meV and a $k$-valley splitting of 100 mV were observed with the inclusion of SOC. The electronic properties were further analyzed using fat band structures and projected density of states (PDOS), which depict the predominant contribution of Mo $d$${}_x$²${}_{-}$${}_y$², $d$${}_{xy}$ and Mo $d$${}_z$² orbital to the valence band maximum (VBM) and conduction band minimum (CBM), respectively. Strain-induced bandgap variation was also observed due to the deformation of the crystal structures by shifting and splitting of the energy levels.

For quite a long time, the scientific community has been searching for a material that surpasses the existing material systems in terms of energy conversion efficiency for photovoltaic applications. In this study, the optoelectronic properties of pure and Al-doped boron arsenide B${{}_{1-}}_x$Al${}_x$As $(x=0,0.125\mathrm{\text{and}}0.25)$ in the zinc blende (ZB) structure were systematically examined using the density functional theory (DFT) and the Modified Becke–Johnson (TB-mBJ) exchange correlation (XC) potential. The Perdew–Burke–Ernzerhof generalized gradient approximation (PBE) functional was used for structural optimization. After considering the ground state lattice constant of 4.82Å then calculating the bandgap energy of pure BAs, which are consistent with experimental and theoretical findings, we estimated the basic electronic and optical characteristics of Al-doped boron arsenide, including band structures, electronic density of state, dielectric function, refractive index, extinction coefficient, absorption and optical conductivity. The unusual and interesting optoelectronic features of the investigated compounds revealed in this work offer substantial promise for improving the energy conversion efficiency of solar cells.

Due to their remarkable mechanical, thermal and electrical characteristics, silicon carbide (SiC) single-walled nanotubes (SWNTs) are an unusual and promising class of materials. Density functional theory (DFT) is used in this study to examine the electrical and structural characteristics of copper-doped SiC armchair SWNTs. It has been discovered that copper doping of SiC armchair SWNTs alters the materials’ electrical characteristics. SiC SWNTs band gap plays a significant role in influencing the electrical conductivity and optical characteristics of the substance. The energy bands i.e., valence band and conduction band of SiC armchair SWNTs overlapped as copper doping concentration increased, altering the materials’ electrical conductivity and optical characteristics. Additionally, a continuous density of states plot and a narrower band gap are frequently employed as markers of ferroelectric behaviour which indicates the existence of a polarizable and highly delocalized electronic system. The significance of copper doping in SiC SWNTs is understood by this study, along with the effects of the doping on the material’s electrical properties.

A comprehensive investigation was conducted to analyze the physical properties, including electronic structure, optical characteristics, and thermoelectric properties, of four zinc blend structures: BAs, AlAs, BBi, and BSb. This analysis utilized first-principles calculations based on Density Functional Theory (DFT) and Boltzmann transport theories, implemented in the WIEN2K simulator program. The compounds examined displayed intriguing electronic and optical properties, such as low indirect band gaps of 0.726, 1.888, 0.867, and 1.51 eV for AlAs, BAs, BBi, and BSb, respectively. Moreover, these compounds exhibited high absorption in the UV–Visible region. Among the four compounds studied, BAs demonstrated exceptional structural stability due to its high bulk modulus and negative formation energy. The thermoelectric study revealed that the Seebeck coefficient decreased with increasing temperature, while the figure of merit was proportional to temperature enhancement. This behavior suggests that the investigated materials hold promise for applications in visible-light solar cell devices.

The potential applications of the cubic phase of CsNbO₃ perovskite have been explored by examining its elastic, electronic, and photocatalytic characteristics using a first-principles approach. The structural robustness when subjected to pressure has been verified by studying the computed elastic constants. Its substantial elastic moduli, hardness, and toughness values propose its suitability for various engineering applications. A transition from flexibility to fragility is observed at pressures exceeding 10GPa. The CsNbO₃ material demonstrates an indirect and narrow band gap, making it a promising candidate in optoelectronic applications. Changes in the band gap due to pressure indicate adjustments in orbital hybridization. The material’s low effective carrier mass and high carrier mobility anticipate favorable electrical conductivity. Assessments of the potentials at the conduction band (CB) and valence band (VB) edges underscore the remarkable capacity of CsNbO₃ for activities such as water-splitting and promoting sustainable energy production.

The electronic and magnetic properties of Be${}_{1-x}$(Gd,Eu,Tb)${}_x$O (with $x$ values of 0.125, 0.25, and 0.375) were systematically investigated using the full-potential linearized augmented plane wave (FP-LAPW) method within density functional theory (DFT). Exchange and correlation potentials were computed employing the generalized gradient approximation (GGA) and GGA plus-modified Becke–Johnson potential (TB-mBJ) approximations. Our findings demonstrate that the incorporation of X into BeO induces magnetism in the compound. Specifically, BeO doped with Gd, Eu, and Tb at $x=0.125,0.25$, and 0.375 exhibits half-metallic behavior, characterized by integer magnetic moments. These results indicate the potential of these compounds to serve as novel half-metallic materials for future spintronics applications, offering exciting prospects in the field.

First-principles based calculations were executed to investigate the sensing properties of ammonia gas molecules on a two-dimensional pristine black phosphorene sheet toward its application as a gas sensor and related applications. We discuss in detail the interaction of ammonia gas molecules on the phosphorene single sheet through the structural change analysis, electronic band gap, Bader charge transfer, and density-of-states calculations. Our calculations indicate that phosphorene could be used as a detector of ammonia, where good sensitivity and very short recovery time at room temperature confirm the potential use of phosphorene in detecting ammonia.