Erratum: Why is the ground state electron configuration for Lithium 1s(2)2s ?

For the variational calculation involving the 1s22s state, we inadvertently filed energy contributions into the wrong categories, with the result that the Virial Theorem appeared to be violated. The overall calculation of the energy was done correctly, and appropriate assignment of the different energy contributions now confirms that the Virial Theorem is obeyed. Obviously, our conclusions are unchanged.

On the Regularity of the Electron Configuration of Atoms in the Periodic Table

The current periodic table does not necessarily have a clear position for transition elements. Therefore, the purpose of this paper is to use the basic principle discovered by Mendeleev as it is and to create a periodic table with consistency for transition elements. By setting some hypotheses, it was found that transition elements also have regular periodicity, so we succeeded in clarifying the energy level of electrons in each orbit. In addition, by utilizing its periodicity, the electron configuration for each orbit was predicted for unknown elements. In this paper, we did not take the conventional idea of electron orbitals, that is, the idea of forming a hybrid orbital, but assumed a new orbital. Since the state in which electrons fit in orbits and stabilize is defined as an octet, this idea was used as the basic principle in this paper, but the hypothesis that "there are only three orbits in each shell" was established and verified. The calculation of the energy level of the electrons on the orbit became extremely easy, and the order of each orbit could be clarified. It was also found that the three-dimensional structure of the molecule may be visualized by paying attention to the valence electrons of the outermost shell of the element and the octet of the stability condition. Therefore, in this paper, by slightly expanding the structural formula of Kekulé, it became possible to easily determine whether or not the molecule synthesized by the bond between elements is stable. In addition, it has become possible to predict the three-dimensional structure of the molecule as well. Furthermore, not only will it be easier for students studying chemistry to understand complex chemical reactions, but it will also be useful for researchers in the development and research of new drugs.

A Systematic Approach for Semiconductor Half-Heusler

The key to designing a half-Heusler begins from the understanding of atomic interactions within the compound. However, this pool of knowledge in half-Heusler compounds is briefly segregated in many papers for specific explanations. The nature of the chemical bonding has been systematically explored for the large transition-metal branch of the half-Heusler family using density-of-states, charge-density, charge transfer, electron-localization-function, and crystal-orbital-Hamilton-population plots. This review aims to simplify the study of a conventional 18-electron configuration half-Heusler by applying rules proposed by renowned scientists to explain concepts such as Zintl-Klemm, hybridization, and valence electron content (VEC). Atomic and molecular orbital diagrams illustrate the electron orbital transitions and provide clarity to the semiconducting behavior (VEC = 18) of half-Heusler. Eighteen-electron half-Heusler usually exhibits good thermoelectric properties owing to favorable electronic structures such as narrow bandgap (<1.1 eV), thermal stability, and robust mechanical properties. The insights derived from this review can be used to design high-performance half-Heusler thermoelectrics.

Conduction Band Engineering of Half-Heusler Thermoelectrics Using Orbital Chemistry

Semiconducting half-Heusler (HH, XYZ) phases are promising thermoelectric materials owing to their versatile electronic properties. Because the valence band of half-Heusler phases benefit from the valence band extrema at several high-symmetry points in the Brillouin zone (BZ), it is possible to engineer better p-type HH materials through band convergence. However, the thermoelectric studies of n-type HH phases have been lagging behind since the conduction band minimum is always at the same high-symmetry point (X) in the BZ, giving the impression that there is little opportunity for band engineering. Here we study the n-type orbital diagram of 69 HHs, and show that there are two competing conduction bands with very different effective masses actually at the same X point in the BZ, which can be engineered to be converged. The two conduction bands are dominated by the d orbitals of X and Y atoms, respectively. The energy offset between the two bands depends on the difference in electron configuration and electronegativity of the X and Y atoms. Based on the orbital phase diagram, we provide the strategy to engineer the conduction band convergence by mixing the HH compounds with the reverse band offsets. We demonstrate the strategy by alloying VCoSn and TaCoSn. The V0.5Ta0.5CoSn mixture presents the high conduction band convergence and corresponding significantly larger density-of-states effective mass than either VCoSn or TaCoSn. Our work indicates that analyzing the orbital character of band edges provides new insight into engineering thermoelectric performance of HH compounds.

Galvanic corrosion inhibition from aspect of bonding orbital theory in Cu/Ru barrier CMP

In this report, the galvanic corrosion inhibition between Cu and Ru metal films is studied, based on bonding orbital theory, using pyridinecarboxylic acid groups which show different affinities depending on the electron configuration of each metal resulting from a π-backbonding. The sp2 carbon atoms adjacent to nitrogen in the pyridine ring provide π-acceptor which forms a complex with filled d-orbital of native oxides on Cu and Ru metal film. The difference in the d-orbital electron density of each metal oxide leads to different π-backbonding strength, resulting in dense or sparse adsorption on native metal oxides. The dense adsorption layer is formed on native Cu oxide film due to the full-filled d-orbital electrons, which effectively suppresses anodic reaction in Cu film. On the other hand, only a sparse adsorption layer is formed on native Ru oxide due to its relatively weak affinity between partially filled d-orbital and pyridine groups. The adsorption behaviour is investigated through interfacial interaction analysis and electrochemical interaction evaluation. Based on this finding, the galvanic corrosion behaviour between Cu and Ru during chemical mechanical planarization (CMP) processing has been controlled.

d- and s-orbital populations in the d block: unbound atoms in physical vacuum versus chemical elements in condensed matter. A Dronskowski-population analysis

The electron configurations of Ca, Zn and the nine transition elements M in between (and their heavier homologs) are reviewed on the basis of density functional theory and experimental facts. The d-s orbital energy and population patterns are systematically diverse. (i) The dominant valence electron configuration of most free neutral atoms M0 of groups g = 2–12 is 3d g−2 4s 2 (textbook rule), or 3d g−14s 1. (ii) Formal M q+ cations in chemical compounds have the dominant configuration 3d g−q 4s 0 (basic concept of transition metal chemistry). (iii) M0 atoms in metallic phases [M∞] of hcp, ccp(fcc) and bcc structures have intermediate populations near 3d g−1 4s 1 (lower d populations for Ca (ca. ½) and Zn (ca. 10)). Including the 4p valence orbitals, the dominant metallic configuration is 3d g−δ 4(sp) δ with δ ≈ 1.4 (±0.2) throughout (except for Zn). (iv) The 3d,4s population of atomic clusters M m varies for increasing m smoothly from single-atomic 3d g−24s 2 toward metallic 3d g−14s 1. – The textbook rule for the one-electron energies, i.e., ns < (n−1)d, holds ‘in a broader sense’ for the s block, but in general not for the d block, and never for the p block. It is more important to teach realistic atomic orbital (AO) populations such as the ones given above.

Structure of the Atom

Structure of the Atom describes the quantum-mechanical model of the atom, which explains the fundamental nature of energy and matter, in terms of how electrons are arranged within atoms and how that arrangement determines the ultimate chemical and physical properties of elements. A discussion of atomic spectra, the Bohr model of the hydrogen atom, and the quantum numbers of an atomic orbital is provided. Other topics include the determination of quantum numbers from energy levels, the shapes of atomic orbitals, electron filling order, and the determination of the complete electron configuration of the elements.