STUDY OF STRUCTURAL AND ELECTRONIC PROPERTIES OF CHROMIUM AND MOLYBDENUM

Abstract

We optimize lattice parameter and identify the nature and values of band gap of Chromium and Molybdenum 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 Chromium and Molybdenum. We optimize lattice parameter and identify the nature and values of band gap of Chromium and Molybdenum. Optimized value of the lattice parameter, kinetic energy (cut off energy),K-point grid of Chromium is obtained as 5.4Bohr ,85Ry ,8×8×8 respectively. Similarly,Optimized value of the lattice parameter, kinetic energy (cut off energy),K-point grid of Molybdenum is obtained as 6.04 Bohr ,85Ry, 8×8×8 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.