Many-electron atom confinement by a penetrable spherical box

摘要

A confinement model for many-electron atoms enclosed by a spherical boundary with finite-barrier potential height is presented. The model is based on the Thomas-Fermi-Dirac-Weizsacker (TFD lambda W) functional formalism using known properties of the orbital electron densities and constitutes a natural extension of a previously published report for the case of infinitely hard walls [Cruz et al., Int J Quantum Chem, 2005, 102, 897]. The confining barrier potential is considered as a step-like function of finite height V-0 This assumption demands of the appropriate description of the TFD lambda W energy functional for both the interior and exterior regions together with corresponding ansatz orbital density representations, subject to continuity boundary conditions at the wan. For a given cage radius R and confining barrier height V-0 the total ground-state energy is variationally optimized with respect to the characteristic parameters defining the interior and exterior orbital densities. The total ground-state energy and corresponding electronic density are obtained as function of barrier height and cage radius for many-electron atoms and ions. The model is explicitly applied to He, Li, C, and Ne and various ionic species for barrier heights (atomic units) V-0 = 0, 5, and infinity. Given a barrier height V-0, the results are presented for the critical cage size to produce one or more unbound electrons-yet, confined by the box-until reaching threshold size values for which electron escape from the confinement region take place. (C) 2008 Wiley Periodicals, Inc.