Structural and dielectric properties of AlN under pressure

We use an ab initio total-energy pseudopotential method within the local density approximation (LDA) to study the structural and dielectric properties of wurtzite, zinc-blende, and rocksalt aluminum nitride (AlN) under hydrostatic pressure. The ground-state properties are determined using a plane-wave pseudopotential method within density functional theory (DFT), while density functional perturbation theory (DFPT) is employed to derive the Born effective charges and high-frequency dielectric constants. Our results are in good agreement with available experimental and previous theoretical data. The pressure dependence of the studied quantities has been examined and discussed. For the rocksalt phase our results concerning dielectric properties are predictions and may serve as a reference for experimental work.