Optical properties of plasmas, including dielectric constants, indices of refraction, and absorption coefficients, are determined from an average-atom point of view. Linear response of an average atom to an harmonic electric field leads to an averageatom version of the Kubo-Greenwood formula, which is used to calculate the frequencydependent electric conductivity of the plasma. The frequency-de...

Dielectric screening of excitons in 2D semiconductors is known to be a highly non-local effect, which in reciprocal space translates to a strong dependence on momentum transfer q. We present an analytical model dielectric function, including the full non-linear q-dependency, which may be used as an alternative to more numerically taxing ab initio screening functions. By verifying the good agree...

The piezoelectric properties of lead zirconate titanate (PZT) thin films deposited on thick silicon substrates and thin silicon membranes were investigated using optical interferometry. The effect of the geometrical constraints and clamping effects on the piezoelectric response is discussed. The study of the dielectric permittivity and the loss as a function of the amplitude of the alternating ...

Finite-difference time-domain (FDTD) methods suffer from reduced accuracy when modeling discontinuous dielectric materials, due to the inhererent discretization (“pixellization”). We show that accuracy can be significantly improved by using a sub-pixel smoothing of the dielectric function, but only if the smoothing scheme is properly designed. We develop such a scheme based on a simple criterio...

In this work we use molecular dynamics simulations to study the diffusion of N,N-dimethylformamide (DMF) and H2O as a function of temperature within the well-known metal-organic framework Co2(dobdc)·[G] (G = 2DMF·1H2O), also known as Co-MOF-74. The molecular dynamics simulations show that the diffusivity of guest molecules, which is almost negligible at low temperatures (T < 200 K), increases i...

The inelastic scattering of fast electrons transmitting thin foils of silicon (Si), silicon nitride (Si(3)N(4)), gallium arsenide (GaAs), gallium nitride (GaN) and cadmium selenide (CdSe) was analyzed using dielectric theory. In particular, the impact of surface and bulk retardation losses on valence electron energy-loss spectroscopy (VEELS) was studied as a function of the foil thickness. It i...

A generalized Born (GB) model is proposed that approximates the electrostatic part of macromolecular solvation free energy over the entire range of the solvent and solute dielectric constants. The model contains no fitting parameters, and is derived by matching a general form of the GB Green function with the exact Green's function of the Poisson equation for a random charge distribution inside...

Spontaneous emission rates in a dielectric structure are position dependent and proportional to the local optical density of states. The latter can be calculated when the Green function is known. In our scalar formalism, we model dielectric slabs as infinitely thin planes and use the T-matrix formalism of multiple-scattering theory to find an exact analytical expression for the Green function o...

Analytical expressions are deduced for the quantitative evaluation of the charge induced on an electrode by a partial discharge (PD) within a dielectric body. Two approaches have been employed to effect this evaluation. These are characterized by the X function and the $ function, and the essential relationships to be fulfilled by X and q5 are derived. The principal difference between these fun...