Structural, elastic, electronic and optical investigations of fluoride-perovskite NaBeF₃: first-principles calculations

First-principles investigation of the ultra-wide band gap halides perovskite XBeF3 (X = Na, K) with pressure effects

“…The lattice constant, elastic constants, bulk modulus and shear modulus at 0 K and 0 GPa were calculated as listed in table 1. The equilibrium lattice constants for NaBeF 3 and KBeF 3 were 3.5721 Å and 3.6753 Å, respectively, which are consistent with the literature values [9][10][11]31]. Thus, the calculated results are very credible with the optimized structure.…”

“…In particular, C 11 relatively quickly increases, while C 44 slowly increases. NaBeF 3 and KBeF 3 crystals are 7.319 eV and 8.255 eV, respectively, which are similar to 7.455 eV [10] and 8.1 eV [9]. When GGA is selected to be the exchange correlation energy function, the band gap values of NaBeF 3 crystals are 7.096 eV, 7.683 eV, 8.147 eV, and 8.537 eV at 0, 10, 20, and 30 GPa, respectively, which are always in the deep ultraviolet range, and the band gap type is always indirect at different pressures.…”

“…Bibi et al [9] investigated the electronic and optical properties of cubic NaBeF 3 at zero temperature and pressure using the first-principles and showed that NaBeF 3 exhibited indirect band gap insulator properties. Hamada et al [10] performed an ab initio method to study the electronic structure, elasticity and optical properties of cubic NaBeF 3 , which showed that NaBeF 3 crystal was a wide band-gap insulator and had important application in high-frequency optoelectronic devices. Li et al [11] applied the ab initio method to study the geometric structure and elastic properties of cubic KBeF 3 crystal at 0 GPa.…”