Study of spatially confined atoms through Density functional theory

 Atom trapped inside a cavity introduces alluring changes in the observable properties. While atom confined by rigid walls is a 

simple model to study electrons restricted to small regions, penetrable walls are more convenient to contrast the corresponding 

results with an experimental counterpart. Here we present few exploratory results obtained from a newly proposed DFT-based method 

in our laboratory to address such confinement in atoms. The radial Kohn-Sham (KS) equation is solved invoking a 

physically motivated non-variational, work-function-based exchange potential, along with a simple parametrized local Wigner 

functional and a nonlinear, gradient- and Laplacian-dependent functional (LYP). GPS method is used to construct an optimized 

non-uniformly discretized spatial grid  for solving the KS equation. Preliminary results are presented for both ground and excited states 

of atoms and ions enclosed within impenetrable and penetrable cages. This includes external potential in the form 

of harmonic confinement, atom/ion embedded in a fullerene cage. The exchange-only results are practically 

of Hartree-Fock quality. The interplay between ordering and crossing of states as functions of cavity radius is analyzed by constructing 

a traditional correlation diagram. Study of such two-electron harmonium atom inside spherical cavity is pursued to conclude whether 

this crossing behaviour is unique to the one-electron coulomb potential or it can be observed in other single-particle confining potential.