The optical properties of titanium dioxide (TiO2) in rutile, anatase and brookite phases were investigated via density functional theory (DFT) framework. Hubbard U term Ti 3d electrons the TiO2 was introduced to observe behavior with effect parameter. calculated structural parameters from optimized are good agreement previous experimental theoretical data. values static dielectric constant refractive index exchange-correlation standard DFT slightly higher than + method. energy peaks...

AbstractThe electronic, structural, elastic, and optical properties of zinc oxide (ZnO) with wurtzite-type structure were investigated using first-principles calculation based on density functional theory (DFT) local approximation (LDA) plus Hubbard U (DFT–LDA+U)method. improved the calculated results, allowing it to exhibit good agreement experimental data. The DFT–LDA+U method successfully predicted electronic ZnO better described localization transition metal Zn 3d electron. dielectric...

The properties of cubic (Pm3m, 221 space group) perovskite prototypes PbTiO3 (PTO), SnTiO3 (STO), and SnZrO3 (SZO) were investigated via first-principles calculation using the density functional theory as implemented in CASTEP computer code. lattice parameters (as reference compound) calculated. accuracy values (GGA-PBEsol) acceptable relative to experimental with typical error approximately 0.6% underestimate. independent elastic constants (C11, C12, C44) bulk modulus, B, obtained analyzed....

The structural, electronic, elastic, and optical properties of BiFeO3 were investigated using the first-principles calculation based on local density approximation plus U (LDA + U) method in frame plane-wave pseudopotential functional theory. application self-interaction corrected LDA improved accuracy calculated properties. Results BiFeO3, good agreement with other experimental data; optimized choice on-site Coulomb repulsion was 3 eV for treatment strong electronic localized Fe 3d...

First-principles calculations are performed to study the electronic properties of zinc oxide (ZnO) formed on an anode after discharging a Zn–air system. Prior calculation, ZnO is characterised by X-ray diffraction using Rietveld refinement. Diffracted patterns proved formation single phase ZnO, while analysis shows that has hexagonal wurtzite structure with lattice parameters, = 3.244 and c 5.199 Å. Geometry optimisation various exchange–correlation energy functionals. The local density...

ZnO nanoparticles were synthesized using the sol–gel method with a variation on sol aging time and refined structural data taken to simulate sample in first-principles calculation. The aged at 36 h showed profound properties high crystallinity good visual fit Rietveld analysis. Optical analysis revealed only small energy band gap for all samples, ranging between 3.08–3.12 eV, presence of oxygen vacancy defects. In calculation, several exchange-correlation functionals, including LDA, GGA-PBE,...

Crystal structures of α-Bi2O3 and β-Bi2O3 were calculated using Cambridge serial total energy package (CASTEP) based on the first-principles plane-wave ultrasoft pseudopotential method within local density approximation (LDA) generalized gradient (GGA) together with Perdew–Burke–Ernzerhof (GGA-PBE) revised for solid (GGA-PBEsol). The structural parameter are in good agreement previous experimental theoretical data. All polymorphs states (TDOS) partial (PDOS) Bi, O atoms. Density exhibits...

The structural, electronic, and optical properties of the special lone pair ferroelectric materials with tetragonal structures, namely, PbTiO3, SnTiO3, GeTiO3 (P4mm, 99 space group), were investigated using density functional theory implemented in a pseudo-potential plane wave CASTEP computer code. electronic indicated that hybridizations occur among anion O 2p, (ns2), Ti 3d states. complex dielectric constant was used to explain comparison ATiO3 (A = Pb,Sn,Ge) relative their electron...

The electronic band structure, density of state and elastic properties lead-free perovskite oxide SnTiO3 (ST) were investigated by employing first principles calculation using the Density Functional Theory (DFT) within local approximation (LDA). energy gap was calculated from separation between Ti 3d (conduction band) maximum O 2p (valence band). This gives an indirect 2.36 eV. constants their pressure dependence up to 30 GPa independent (C11, C12, C44), bulk modules, B obtained analyzed....

The properties of tetragonal (P4 mm, 99 space group) SnTiO3 were investigated via first-principles implemented in CASTEP computer code. calculation formation energy shows that the P4 mm with lowest optimization is at ground state equilibrium structure compared to ilmenite structure. result also has a higher tetragonality (c/a = 1.18). Moreover, elastic constant confirmed this compound phase good mechanical stability. electronic indicated hybridizations occur among anion O 2p, cation Sn 5s...

Abstract Good thermoelectric performance is being sought to face major problems related energy, especially in the concern of usage energy on environmental impact. In this work, we investigate underlying mechanism enhance bismuth selenide (Bi 2 Se 3 ) by employing density functional theory (DFT) followed Boltzmann transport equation under relaxation time approximation. The structural, electronic, and properties were calculated analyzed. From analysis combined results electronic as function...

First principles calculations within framework of the density functional theory (DFT) have been carried out to investigate structural, electronic and optical properties zinc doped magnesium oxide (ZnxMg1-xO) with different concentration (x=0, 0.125 0.25). The crystal structure used in this calculation was cubic MgO space group Fm-3m supercell 2x1x1. total energy calculated order predict suitable position dopant. Increased resulting lattice parameters ZnxMg1-xO increase band gap material were...

The structural and electronic properties of bismuth ferrite (BFO) in ferroelectric hexagonal phase paraelectric orthorhombic are investigated using ab initio density functional theory calculation. Calculations based on generalized gradient approximation GGA–PBEsol with semi-empirical Hubbard U method show good results for the localization Fe 3d electrons consistent experimental data. In addition, calculated band structure BFO shows a smaller energy gap than phase. Thus, this calculation is...

Structural, electronic and optical properties of titanium dioxide (TiO2) in brookite phase were studied via first-principles calculations the framework density functional theory (DFT). The exchange-correlation from local approximation (LDA) generalized gradient (GGA) used to calculate TiO2. structural parameters orthorhombic structure (Pbca space group) are good agreement with previous theoretical experimental data. obtained direct band gaps GGA slightly higher than LDA. Both LDA...

The exchange-correlation functions of local density approximation and generalized gradient using functional theory were performed to calculate electronic optical properties lithium niobate crystal. To correct the underestimated value band gap, a reverse scissor correction procedure was based on experimental refractive index because it is more suitable for compound with polar It found that gap ∼4.76 eV generated due nature (GGA) exchange correlation. Based states calculation, Li ion tends...

The geometry optimization, elastic constant, electronic band structure, density of state (DOS) and optical properties perovskite SnZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> (SZ) are investigated from first principles calculation using the Density Functional Theory (DFT) within Local Approximation (LDA). All calculations performed Cambridge Serial Total Energy Package (CASTEP) computer code. independent constants (C...