Dynamic flexoelectric effect in perovskites from first-principles calculations

Using the dynamical matrix of a crystal obtained from ab initio calculations, we have evaluated the strength of the dynamic flexoelectric effect and found it comparable to that of the static bulk flexoelectric effect, in agreement with earlier order-of-magnitude estimates. We also propose a method of evaluation of these effects directly from the simulated phonon spectra. This method can also be applied to the analysis of the experimental phonon spectra, currently the only one enabling experimental characterization of the static bulk flexoelectric effect.