First Principles Study of Electronic and Optical Properties of BaF2

Abstract

Barium fluoride (BaF2) is an important member of alkaline-earth fluorides for its intrinsic optical
properties. The structural, optical properties, phonon frequencies, and dielectric constants have been
investigated with ab initio density functional theory (DFT) method and Density functional
perturbation theory (DFPT). The calculations had been done using a first principle code Quantum
espresso, implemented ultra-soft pseudo-potentials (US-PPs) and projector augmented wave (PAW)
data sets with the local density approximation (LDA) and the Generalized Gradient Approximation
(GGA) for the exchange-correlation. The optimized lattice parameters, phonon frequencies at main
symmetry points of the Brillouin zone and dielectric constants resulting of pseudo-potentials used
were in a good agreement with other theoretical and experimental data.