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Lithium-ion batteries employing graphite as the anode material are now widely used in powering electronic gadgets like, mobile phones, laptops, electronic watches and calculators and also to provide required power to run engine of electric vehicles. However, storage capacity, open circuit voltage, energy density and battery life are the major considerations on which researchers are trying different alternatives to achieve better performance of the battery. In this research, Beryllium-doped and defective graphenes have been investigated by employing the ab initio DFT method. It has been found that graphene with a defect and Be–doped graphene with defects can serve as an efficient materials for anode in Li-ion batteries.

Structures, binding energies, magnetic and electronic properties endohedrally doped C₂₀ fullerenes by metallic atoms (Fe, Co, Ti and V) have been obtained by pseudopotential density functional theory. All M @C₂₀, except Co@C₂₀, are more stable than the undoped C₂₀ cage. The magnetic moment values are 1 and 2μ_B. These values and semiconductor behavior give to these compounds interesting feature in several technological applications. Titanium doped C₂₀ has a same magnetic moment than the isolated Ti atom. Hybridization process in the Co doped C₂₀ fullerene is most strong than in other doped cages. Electrical and magnetic dipoles calculated in the iron doped C₂₀ are very strong compared with other clusters.

The lowest-energy geometric and isomers of freestanding Co_n clusters (n = 2 - 10) and their corresponding magnetic moments have been studied using the Siesta code based on pseudopotential density-functional theory. The calculated results show that there are many isomers near the ground state. Different isomers hold different magnetic moment. The stability study shows that among the investigated clusters, the hexamer one is the most stable and is the magic cluster. Dissociation channels energy are also studied.

In this review article, we survey the relatively new theory of orbital magnetization in solids — often referred to as the "modern theory of orbital magnetization" — and its applications. Surprisingly, while the calculation of the orbital magnetization in finite systems such as atoms and molecules is straight forward, in extended systems or solids it has long eluded calculations owing to the fact that the position operator is ill-defined in such a context. Approaches that overcome this problem were first developed in 2005 and in the first part of this review we present the main ideas reaching from a Wannier function approach to semi-classical and finite-temperature formalisms. In the second part, we describe practical aspects of calculating the orbital magnetization, such as taking k-space derivatives, a formalism for pseudopotentials, a single k-point derivation, a Wannier interpolation scheme, and DFT specific aspects. We then show results of recent calculations on Fe, Co, and Ni. In the last part of this review, we focus on direct applications of the orbital magnetization. In particular, we will review how properties such as the nuclear magnetic resonance shielding tensor and the electron paramagnetic resonance g-tensor can be elegantly calculated in terms of a derivative of the orbital magnetization.

The electronic structure and its derived valence and conduction charge distributions along with the optical properties of zinc-blende GaAs${}_{1-x}$P${}_x$ ternary alloys have been studied. The calculations are performed using a pseudopotential approach under the virtual crystal approximation (VCA) which takes into account the compositional disorder effect. Our findings are found to be generally in good accord with experiment. The composition dependence of direct and indirect bandgaps showed a clear bandgap bowing. The nature of the gap is found to depend on phosphorous content. The bonding and ionicity of the material of interest have been examined in terms of the anti-symmetric gap and charge densities. The variation in the optical constants versus phosphorous concentration has been discussed. The present investigation may give a useful applications in infrared and visible spectrum light emitters.

Based on the pseudopotential scheme under the virtual crystal approximation that takes into account the effect of compositional disorder combined with the bond-orbital model of Harrison, the results of calculations of elastic constants and surface and bulk acoustic wave speeds of Cd_1-xZn_xTe mixed crystals in the zinc-blende structure are presented. The agreement between our results and known data, which are only available for CdTe and ZnTe is found to be reasonable.

In this paper, by introduction of pseudopotentials, the nonlocal symmetry is obtained for the Ablowitz–Kaup–Newell–Segur system, which is used to describe many physical phenomena in different applications. Together with some auxiliary variables, this kind of nonlocal symmetry can be localized to Lie point symmetry and the corresponding once finite symmetry transformation is calculated for both the original system and the prolonged system. Furthermore, the nth finite symmetry transformation represented in terms of determinant and exact solutions are derived.

Relativistic energy-consistent small-core lanthanide pseudopotentials of the Stuttgart–Köln variety and corresponding valence basis sets have been used for the investigation of the ground state (¹Σ⁺) lanthanum monohalides LaF, LaCl, LaBr, and LaI. The molecular constants were derived from coupled-cluster calculations, taking into account corrections for atomic spin-orbit splitting as well as basis set superposition errors. With the exception of the binding energies for LaI the theoretical values for LaF (R_e = 2.034 Å, D_e = 6.73eV, ω_e = 574cm^-1), LaCl (R_e = 2.517 Å, D_e = 5.11eV, ω_e = 339cm^-1), LaBr (R_e = 2.664 Å, D_e = 4.47eV, ω_e = 236cm^-1), and LaI (R_e = 2.891 Å, D_e = 3.65eV, ω_e = 186cm^-1) show good agreement with the experimental data. The calculated binding energy (3.65 eV) for LaI is in-between the two conflicting estimated experimental data (2.97 eV, 4.29 eV).

The potentials for excess electrons in cavities of water and methane are analyzed with the use of the pseudopotential theory. The results are consistent with the previous discussions; the excess electron in water can probably be trapped in the cavity and that in methane will be quasifree. In the case of methane, the effect of the molecular coordination on the potential is further discussed by varying the cavity radius.