First-principles calculation of the dielectric properties of GaAs: Dielectric constant, effective charges, and piezoelectric constant

We present the results of an ab initio calculation of the macroscopic dielectric properties of GaAs. The electronic dielectric constant, the effective charges, and the piezoelectric constant are calculated at several finite were vectors in the density-functional approach, and these results are extrapolated to zero wave vector. The extrapolated values for the dielectric constant and the effective charges are in excellent agreement with experiment: ${\epsilon }_{\infty }=10.9\mathrm{}$ (experiment, 10.9), and $\left|e_T^{*}\right|=2.32\mathrm{} \mathrm{}\left(2.16\right)\mathrm{}$. The extrapolated value of the piezoelectric constant also is in good agreement $\left(\frac{a_0}{e^2}\right)e_{14}=-0.14\mathrm{}\mathrm{}(-0.16\mathrm{})\mathrm{}$, although the uncertainty is large.