Current-density implementation for calculating flexoelectric coefficients

Upper bounds for flexoelectric coefficients in ferroelectrics

Flexoelectric effect is the response of electric polarization to the mechanical strain gradient. At the nano-scale, where large strain gradients are expected, the flexoelectric effect becomes appreciable and may substitute piezoelectric effect in centrosymmetric materials. These features make flexoelectricity of growing interest during the last decade. At the same time, the available theoretica...

Relationship between direct and converse flexoelectric coefficients

Measurement of Flexoelectric Coefficients of Some Nematic Liquid Crystals

As we have discussed in Chapter I of this thesis, the nematic director is apolar. IIence the usual dielectric coupling with an external electric field depends quadratically on the latter. However, as has been discussed earlier a deformed director field with a splay and/or bend distortion can lead to a flexoelectric polarisation of the medium. The response of liquid crystals to an electric field...

Assessment of range-separated time-dependent density-functional theory for calculating C6 dispersion coefficients.

We assess a variant of linear-response range-separated time-dependent density-functional theory (TDDFT), combining a long-range Hartree-Fock (HF) exchange kernel with a short-range adiabatic exchange-correlation kernel in the local-density approximation (LDA) for calculating isotropic C6 dispersion coefficients of homodimers of a number of closed-shell atoms and small molecules. This range-sepa...

Calculating Bpm Coefficients with Green’s Reciprocation Theorem

For a highly relativistic charged beam, the Lorentz contraction compresses the electromagnetic field of the beam into the 2-D transverse plane. This results in the induced currents on the beam chamber wall having the same longitudinal intensity modulation as the charged beam. When the wavelength of the beam intensity modulation is large compared to the dimensions of the button electrodes, which...