Structural, electronic, optical and thermodynamic properties of AeBi2O6 (Ae ¼ Sr and Ba): Insights from first principles study
Journal: Journal of Molecular Graphics and Modelling
Author: Do Minh Hoat
First principles calculations based on Full-Potential Linearized Augmented Plane-Wave (FP-LAPW) method have been carried out to study the structural, electronic and optical properties of AeBi2O6 (Ae = Sr and Ba) compounds. Optimal crystal structure is found out by optimizing lattice constants and internal parameters of constituent atoms using the Generalized Gradient Approximation as proposed by Wu-Cohen (GGA-WC). While the electronic, dielectric and optical properties of considered materials are investigated using original Becke-Johnson (BJ) potential as it reproduces very reasonable indirect band gaps as compared with experimental ones with value of 1.769 eV and 1.822 eV for SrBi2O6 and BaBi2O6, respectively. The interactions between O-2p and Bi-5s-5p, which are responsible of photocatalytic activity of studied compounds, are demonstrated. Finally, the Debye quasi-harmonic model is used to calculate the thermodynamic properties including bulk modulus, heat capacities, thermal expansion, Debye temperature and entropy of AeBi2O6 compounds. All of them are investigated for wide range of temperature up to 1200 K and of pressure up to 45 GPa.