Study of Structural and Electronic Properties of Antimony and Bismuth

Abstract

We optimize lattice parameter and identify the nature and values of band gap of Antimony and Bismuth by using quantum espresso.This work includes the general introduction on crystal structure and different models that work in the lattice constant and lattice dynamic. We also briefly include various theoretical details such as Born-Oppenheimer Approximation, Hartree-Fock Approximation, Density Functional Theory, Kohn-Sham approach, Local Density approximation, Generalized Gradient Approximation, and pseudo- potential. Finally, we discussed the fundamentals of Quantum Espresso computational program with the result and discussion on electronic properties, kinetic energy cut-off, lattice parameter, band gap, density of state and partial density of state of Antimony and Bismuth. We optimize lattice parameter and identify the nature and values of band gap of Antimony and Bismuth structure. Optimized value of the lattice parameter, kinetic energy (cut off energy),K-point grid and band gap of Antimony is obtained as 8.2870 au ,80 Ry,8×8×8 and 0.15eV respectively. Similarly,Optimized value of the lattice parameter, kinetic energy (cut off energy),K-point grid and band gap of Bismuth is obtained as 4.7459001541 Bohr ,65 Ry,10×10×10 and 0.09eV respectively.We used norm-conserving pseudo potentials; self consistent calculations employed Density Functional Theory (DFT) under Generalized Gradient Approximation (GGA) by using Quantum ESPRESSO package.