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Kinetic Energies and Exchange Model Potentials Calculated with a Simple Analytical Representation of Atomic Densities

L. Pacios
Journal / Anthology

Journal of Physical Chemistry
Year: 1994
Volume: 98
Page range: 3688-3693

A simple analytical representation of Hartree-Fock atomic densities recently devised defined p(r) as a sum of exponentially decaying functions. This basis set-independent representation is here applied to the calculation of kinetic energies, making use of various well-known kinetic energy functionals. Despite its extreme simplicity, these functions provide highly reliable representations of p(r), allowing the calculation of kinetic energies to within 1% or less. This representation of the density is also analyzed in exchange-only functional calculations. A semiempirical model exchange potential developed before (Pacios, L.F. J. Phys. Chem 1992, 96, 7294) is here modified and analyzed. This potential presents three valuable features: reproduces the exact exchange energies, exhibits the correct asymptotic trend when r -> infinity, and displays a spatial behavior close to the numerical exchange optimized potential model by Talman et al.

*Science > Physics > Nuclear and Particle Physics