Confined atoms model helium

Here we consider [25] the properties of H at the centre of a spherical box of radius R, using a numerical approach to obtain the energies and polarizabilities. We also develop some model wave functions, simple expressions for the energies and polarizability, deduce the critical radius R for which E = 0, and extend the analysis to the confined helium atom with effective screening. 

The confinement model has been extensively used to analyze the hydrogen atom enclosed by hard and soft spherical boxes [1-98], with confining boxes of diverse geometrical shapes [31,88-98], and it has also been applied to studies of the helium atom [99-122], many-electron atoms [50, 52,55,123-131], molecules [132-142] and the harmonic oscillator [143-171], among others. 

Sabin and Sabin [109] studied confinement effects on the mean excitation energy of atoms and molecules. In particular, they analyzed the effect of confinement on /o, the mean excitation energy for helium. Iq is the material parameter that characterizes the ability of the target to absorb energy, independent of the nature of the incident particle. They use the jellium model, in which the ellipsoids possess impenetrable boundaries and are filled up by a uniform electron gas, whose number is precisely the number of electrons... 

Comparative Study Between the Hartree-Fock and Kohn-Sham Models for the Lowest Singlet and Triplet States of the Confined Helium Atom... 

Protons and neutrons each contain three quarks. A neutron consists of one up quark and two down quarks. A proton consists of two up quarks and one down quark. Other quarks are named strange, charm, bottom, and top., but these four are not part of atoms. Quarks are a fundamental constituent of matter according to current standard model of particle physics, but individual quarks are not seen. Instead they are always confined within other subatomic particles. There is no need to consider quarks when describing chemical interactions. Only electrons are involved in chemical reactions. The position and sizes of these particles in a helium atom is indicated in the diagram at right. A diagram... 

Two-electron systems are the most studied systems in quantum mechanics due to the fact that they are the simplest systems that contain the electron-electron interaction, which is a challenge for the solution of the Schrodinger equation [1], In particular, helium-like atoms are used many times as a reference to apply new theoretical and computational techniques. Additionally, in recent years the study of many-electron atoms confined spatially have a particular interest since the confinement induces important changes on the electronic structure of these systems [2, 3], The confinement imposed by rigid walls has been quite popular from the Michels proposal made 76 years ago [4], followed by Sommerfeld and Welker one year later [5]. Such a model assumes that the external potential has the expression... 

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