Improved local density approximation to the exchange and kinetic energy functionals for atomic systems

Through the derivation of a bound to the gradient correction for the exchange energy, a new local density (LD) approximation to the exchange energy density functional and an analogous LD form for the kinetic energy density functional are proposed. Both these gradient-free functionals valid for spherically symmetric electron densities, yield excellent results for exchange and kinetic energies, using Hartree-Fock atomic densities