Related Experiment Video
Updated: Jun 23, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Exact dynamical exchange-correlation kernel of a weakly inhomogeneous electron gas
V U Nazarov1, G Vignale, Y-C Chang
1Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan.
Abstract:
The dynamical exchange-correlation kernel f{xc} of a nonuniform electron gas is an essential input for the time-dependent density-functional theory of electronic systems. The long-wavelength behavior of this kernel is known to be of the form f{xc}=alpha/q{2} where q is the wave vector and alpha is a frequency-dependent coefficient. We show that in the limit of weak nonuniformity the coefficient alpha has a simple and exact expression in terms of the ground-state density and the frequency-dependent kernel of a uniform electron gas at the average density. We present an approximate evaluation of this expression for Si and discuss its implications for the theory of excitonic effects.
Related Concept Videos
Electrostatic Boundary Conditions in Dielectrics
Consider a case where both the mediums across a boundary are two different dielectric materials. Recall that the electric field and electric displacement are proportional and related through the material's permittivity.
Debye–Huckel–Onsager Conductance Equation
Equilibrium Conditions for a Particle
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
Energy Associated With a Charge Distribution
Gauss's Law in Dielectrics
Fermi Level Dynamics
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
