Kullback–Leibler and relative Fisher information as descriptors of locality

Abstract

<p>Kullback–Leibler and relative Fisher information functionals are applied in studying deviation from<br />local density approximation. The reduced density gradient s and the local kinetic energy parameter<br />a are key ingredients of these new locality descriptors. The relative Kullback–Leibler information<br />density contains extra knowledge as it is negative where the given probability density is smaller<br />than the reference density. The relative Fisher information incorporates the highest order deviations<br />from the uniform electron gas approximation.<br /></p>