Electron Shells of Periodic Table Elements Visualized by Localized Orbital Locator: Analyzing the Atom’s Structure and Properties

All electron shells of 118 elements of the periodic table are visualized using the parameters of the (3,–3) critical points in the topology of the localized orbital locator function, and a consistent compression of shells with increasing atomic number (Z) is demonstrated. A relationship is established between the properties of atoms (atomic size, ionization energy, electronegativity) and the parameters of the (3,–3) critical points of the outer shell. This interconnection allows scanning of activity centers, analysis of reactivity, and local properties of atoms in molecules via parameters of the (3,–3) critical points. Based on the parameters of the (3,–3) critical points as electronegativity descriptors, a ranking of 24 known electronegativity scales is performed for the sp-, d-, and f-blocks of the periodic table elements. Using these descriptors, a correction of the Pauling electronegativity scale is carried out to obtain new electronegativity values. The parameters of the (3,–3) critical points provide a digital visualization of phenomena such as the relativistic contraction of electron shells, as well as the lanthanide and actinide contraction, at the level of all electron shells.