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This work reports first-principle calculations for LiMgP half-Heusler compound doped by the transition metal elements Cr, Mn, Co and Ni motivated by present findings, in which the ferromagnetism conduct is predicted. The studied LiMg${}_{0.95}{Y}_{0.05}$P alloy ($Y=\mathrm{\text{Cr}}$, Mn, Co and Ni) showed the ferromagnetic behavior. The calculations revealed that the main contributions to the net magnetization come from Cr, Mn, Co and Ni. The Cr${{}^2}^{+}$ will have four electrons, in which 2 electrons are in $e^{+}$ and other 2 occupy the $t_2^{+}$. Then, this orbital is set on the Fermi level. For LiMg${}_{0.95}$Co${}_{0.05}$P alloy, the half-metallic conduct is estimated with 100% polarized on the downside of the Fermi level. Also, LiMg${}_{0.95}$Ni${}_{0.05}$P alloy exhibits the half-metallic conduct on the downside of the Fermi level which is occupied by $t_2^{-}$ minority state. This study stated that electronegativity and magnetic properties have correlation with regard to Cr-, Mn-, Co- and Ni-doped LiMgP, in which the trends of partial moments, electronegativity and total moments are $M^{\mathrm{\text{Ni}}}<M^{\mathrm{\text{Co}}}<M^{\mathrm{\text{Cr}}}<M^{\mathrm{\text{Mn}}}$; ${\chi }^{\mathrm{\text{Ni}}}>{\chi }^{\mathrm{\text{Co}}}>{\chi }^{\mathrm{\text{Cr}}}>{\chi }^{\mathrm{\text{Mn}}}$ and $M_{{\mathrm{\text{LiMg}}}_{0.95}{\mathrm{\text{Ni}}}_{0.05}\mathrm{\text{P}}}^{\mathrm{\text{Tot}}}<M_{{\mathrm{\text{LiMg}}}_{0.95}{\mathrm{\text{Co}}}_{0.05}\mathrm{\text{P}}}^{\mathrm{\text{Tot}}}<M_{{\mathrm{\text{LiMg}}}_{0.95}{\mathrm{\text{Cr}}}_{0.05}\mathrm{\text{P}}}^{\mathrm{\text{Tot}}}<M_{{\mathrm{\text{LiMg}}}_{0.95}{\mathrm{\text{Mn}}}_{0.05}\mathrm{\text{P}}}^{\mathrm{\text{Tot}}}$.

This paper aims to investigate the behavior of LiMgN half-Heusler (HH) semiconductor doped by transition metals (TM $=$ Mn, Fe, Co and Ni). HHs belong to the $F\bar{4}3m$ space group (No. 216) and have a zinc blende structure that can be described by the chemical symbol XYZ. The research methodology utilized in this investigation involves theoretical analysis based on the principles of density functional theory (DFT). The studied LiMg${}_{0.95}$TM${}_{0.05}$N alloy displayed the half-metallicity behavior when TM $=$ Fe, Co and Ni. Hence, these systems could be a promising candidate in spintronic application thanks to their ferromagnetism. The principal contribution to magnetism in the full LiMg${}_{0.95}$TM${}_{0.05}$N alloys comes from the Mn, Fe, Co and Ni doping. The partial magnetic moments of these elements are significantly greater than the combined partial magnetic moments of Li, Mg and N. When comparing LiMg${}_{0.95}$Mn${}_{0.05}$N to LiMg${}_{0.95}$Fe${}_{0.05}$N, ₅Co${}_{0.05}$N and LiMg${}_{0.95}$Ni${}_{0.05}$N, it is important to note that the exchange splitting energy ${\mathrm{\Delta }}_{(e^{+},e^{-})}^{\mathrm{\text{TM}}}$ associated to their spin up and spin down were discussed. The variation of Mn(3d) in relation to ($e^{+},e^{-}$) is larger than that of Fe, Co and Ni. Therefore, ${\mathrm{\Delta }}_{(e^{+},e^{-})}^{\mathrm{\text{Mn}}}>{\mathrm{\Delta }}_{(e^{+},e^{-})}^{\mathrm{\text{Fe}}}>{\mathrm{\Delta }}_{(e^{+},e^{-})}^{\mathrm{\text{Co}}}>{\mathrm{\Delta }}_{(e^{+},e^{-})}^{\mathrm{\text{Ni}}}$. Furthermore, there is a correlation between the magnetic moment and electronegativity trend of the TM dopant. Specially, the electronegativity trend (${\chi }^{\mathrm{\text{TM}}})$ is well matched with the total spin moment trend, where ${\chi }^{\mathrm{\text{Ni}}}>{\chi }^{\mathrm{\text{Co}}}>{\chi }^{\mathrm{\text{Fe}}}>{\chi }^{\mathrm{\text{Mn}}}$.

This paper presents a systematical analysis of the structure and electronic properties of armchair single-walled carbon nanotubes (SWCNTs) as well as single-walled silicon carbide nanotubes (SiCNTs) by using density functional theory. The geometries of all species were optimized at the B3LYP level of theory using the SVP basis set. The different behavior of C–C bonds "parallel" and "perpendicular" to the nanotube axis has been found. The HOMO–LUMO energy gap, ionization potential, electron affinity, electronegativity and hardness of studied tubes were compared. The influence of both SWCNTs and SiCNTs lengths on their electronic properties has been analyzed.

The atom-bond electronegativity equalization method (ABEEM) and its applications for predicting intrinsic properties of large molecules, such as the charge distribution, the molecular energy, the local softness and the Fukui function, the regio- and stereo-selectivity of Diels–Alder reactions, the linear response function, and the charge polarization normal modes have been formulated. The examples show that there is a very good agreement of the ABEEM results with those of the corresponding ab initio quantum chemical calculations, demonstrating the reasonable and possible ABEEM's applications to the large molecular systems.

The semiclassical path integral approach is undertaken to develop new definitions and atomic scales of electronegativity and chemical hardness. The considered quantum probability amplitude up to the fourth-order expansion provides intrinsic electronegativity and chemical hardness analytical expressions in terms of principal quantum number of the concerned valence shell and of the effective atomic charge including screening effects. The present electronegativity scale strikes on different orders of magnitude down groups of the periodic table, while still satisfying the main required acceptability criteria regarding the finite difference–based scale. The actual chemical hardness scale improves the trend across periods of the periodic system, avoiding the usual irregularities within the old-fashioned energetic picture. The current quest introduces the electronegativity of an element as the power by which the frontier electrons are attracted to the center of the atom being a stability measure of the atomic system as a whole.

For the first time, a general viewpoint of electronegativity and chemical bond in alloy semiconductors, e.g., Mg_xZn_1-xO(x = 0.0-1.0) was proposed. The variation of bulk modulus and bond length, as well as their dependence on Mg concentration x were quantitatively simulated. The bulk moduli of Mg_xZn_1-xO alloys decrease with increasing Mg concentration x. The detailed variation of bond lengths of both Mg–O and Zn–O in Mg_xZn_1-xO alloys in the whole composition range was determined, which is less than 0.007 Å. The valence state of Mg is larger than that of Zn when x = 0.0-1.0, which leads to the increase of valence state of O with increasing Mg concentration x. The current results clearly indicate that Mg_xZn_1-xO condenses in an alloy state.

We have proposed an efficient method to quantitatively calculate the band gap values of ternary A_xB_1-xC and AB_xC_1-x alloyed semiconductors in terms of the dopant concentration x and some fundamental atom parameters such as electronegativity. The calculated band gap values of some typical alloyed semiconductors can agree well with the available experimental data. Taking Mg_xZn_1-xO and Cd_xZn_1-xO as examples, the composition dependent band gap values of alloys with both wurtzite and rocksalt structures were quantitatively predicted. This work provides a guideline in compositionally tuning the band gap of alloyed semiconductors, which will greatly facilitate the band gap engineering of semiconductors.

For the first time, this work indicates that mechanical concerns of inorganic materials are highly demanded when well optimizing their functional applications. We quantitatively give the proper data of hardness on different planes of some representative inorganic functional materials including borides, carbides, nitrides and oxides. This work clearly indicates mechanical importance in studying functionality of inorganic materials, and provides people guidance in the practical applications of these materials.

We have developed empirical equations to quantitatively calculate the band gap values of binary A^NB^8-N and ternary ABC₂ chalcopyrite semiconductors from the general viewpoint of chemical bonding processes upon electronegativity (EN). It is found that the band gap of crystal materials is essentially determined by the binding energy of chemical bonds to the bonding electrons, which can be effectively described by the average attractive abilities of two bonded atoms to their valence electrons and the delocalization degree of the valence electrons. The calculated band gap values of a large number of compounds can agree well with the available experimental data. This work provides us an efficient approach to quantitatively predict the band gap values of inorganic crystal materials on the basis of fundamental atom parameters such as EN, atomic radius, etc.

Solid solutions (SS) of 3- and 4-component systems based on lead titanate-zirconate were prepared by the method of solid-phase reactions and uniaxial hot pressing. The dependences of the relative permittivity of polarized samples on the electronegativity (EN) of their constituent cations have been studied. The ferro-hardness of the SS (the stability of the domain structure to external influences) is shown to be directly dependent on the EN of elements B in the corresponding oxidation states, i.e., the degree of covalence of the B–O bond. The deviation from this dependence in SS with Ni and Cd is explained by their individual features, which result in changes in the degree of bond covalence in both cationic sublattices. The conducted crystal-chemical analysis made it possible to choose promising SS when creating ferroelectric materials, including textured piezoelectric ceramic materials for piezoelectric transducers for various purposes: Piezotransformers, piezoelectric motors, ultrasonic emitters, filter devices, ultrasonic flaw detectors, accelerometers, etc.

The stability of an organic compound depends on its nature and the environment in which it is placed. It depends on the presence or absence of reagents (acid, base, oxidizing agent, reducing agent, light, etc.) and catalysts. The stability may not be the same in the solid, liquid or gaseous state. In a homogenous solution, the stability might be affected by the polarity of the solvent and its concentration. For instance a polar solvent favors ionization. In a non-polar solvent ionization is difficult. In the gas phase ionization never occurs. In the gas phase and in solution stability depends on pressure and the presence of impurities. We are interested here in the thermal stability of pure compounds in the gas phase or in non-polar solvents under one atmosphere…