Hybrid density-functional calculations of structural, elastic and electronic properties for a series of cubic perovskites CsMF3 (M = Ca, Cd, Hg, and Pb)

Abstract

Four perovskite crystals CsMF3 (M=Ca, Cd, Hg, and Pb) have been analyzed in details using the hybrid density functional theory, as implemented in CRYSTAL09 program. Among these four crystals, three (M=Ca, Hg, and Pb) are considered for the first time, to the best of the authors’ knowledge. The optimized basis sets were used for calculations of the structural, electronic and elastic properties of these hosts at ambient and elevated hydrostatic pressures. The pressure coefficients for the band gaps, lattice constants and M–F distances were all determined. Elastic anisotropy for all hosts was visualized by drawing three-dimensional dependences of the Young’s moduli on the direction in the crystal. It was shown that the greatest value of the Young’s modulus is realized when the stress is applied along the crystallographic axes, whereas the smallest value corresponds to the stress applied along the diagonal in each of the (a, b), (b, c), and (a, c) planes.