The filling of shells in compressed atoms

Abstract

The energy spectra of ground-state, ionized and excited multielectron atoms and ions of the 3d and 4d periods of the periodic table centred in impenetrable spherical confinement are detailed using Hartree-Fock configuration average calculations. It is shown explicitly for the first time that, owing to modifications in 3d and 4d orbital collapse, the filling of shells for the confined transition sequences becomes more regular than for free atoms with increasing confinement pressure, that s-d competition disappears, and that, for d-excited states, the crossings between inner-shell excited states and the double-ionization thresholds are altered. In general, the periodic table for confined (compressed) atoms can differ from that for free atoms. The importance of these findings for different branches of basic and applied physics and chemistry is indicated.

Effect of strongly coupled plasma on the spectra of hydrogenlike carbon, aluminium and argon

“…The spectral properties of atomic systems are modified considerably under external confinements [1][2][3]. Of particular interest, is the effect of a surrounding plasma of different coupling strengths Γ , defined as the ratio of average Coulomb potential energy between pairs of particles and their kinetic energy.…”

Energy levels and structural properties of compressed hydrogen atom under Debye screening

“…The method has been applied in a number of cases (Hiroike 1965;Hikman 1975;Beau 1996). Basically the problem is similar to that of studying the spectra of compressed atoms like that trapped in zeolite, fullerenes or under high pressure (Jaskolski 1996;Connerade 2000;Gupta 1982). As ab-initio calculations for atoms in such an environment is very complicated, the problem of the impurity atom Send offprint requests to: P. K. Mukherjee, e-mail: sppkm@mahendra.iacs.res.in embedded in liquid helium may alternatively be looked upon using a suitable model in the following manner.…”

Statistical atomic models with complete neglect of differential overlap for the study of free and confined systems

“…This problem has been tackled through HF theory for first-row atoms by Ludeñ a [9] and more recently by Connerade et al [10] and through Kohn-Sham theory by Garza et al [11]. However, to our knowledge no attempt has been made so far using the basic TFDW functional.…”

“…We note, however, that the selfconsistent field (SCF) calculations by Ludeñ a were performed without full basis set optimization for each value of R and assuming that the size of the extended orbital basis would compensate for the lack of exponent optimization in the HF treatment of compressed atoms. A more recent HF calculation by Connerade et al [10] for some third-and fourth-row elements under the same confinement conditions allows for an alternative comparison. Unfortunately, no tabulated values for their energies are reported; hence, we compare in Figure 5 our values (solid circles) for the total ground-state energy for calcium (see Table IV) against confinement radius with values extracted from those graphically reported by the latter authors (open circles).…”

“…It is shown that minimization of the TFDW energy functional relative to the orbital parameters yields accurate total energies as compared with corresponding HF calculations [8] for free atoms as well as for atoms under confinement [9,10]. In contrast, the corresponding description of total atomic radial densities and shell structure is found to be moderate as compared with HF radial densities except for the position and amplitude of the K-and L-shell maxima.…”