First Principle Calculation of Al(100) surface using quantum espresso package

Abstract

In this thesis the first principle calculation of Aluminum surface(Al100) is investigated with density functional theory (DFT) using Quantum Espresso package. Our study is based on Density Functional Theory (DFT) with the Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional, Vanderbilt (ultra soft) pseudopotentials and the plane wave basis set implemented in the Quantum-ESPRESSO package. The calculation of the total minimum energy and the total minimum force ofAl(100) is calculated as a function of cutoff energy and K-points sampling. The total minimum values are selected at the points of convergence. These convergence values are then used as inputs for the calculation of equilibrium lattice constant, energy band gap and density of state of Al(100). However, this trend can not be predicted from increasing the k-points sampling. Moreover, the equilibrium lattice constant is calculated using results obtained from energy convergence test (i.e., 50 Ry and 17 ×17 ×1).The calculated values of the equilibrium lattice constant are a = 5.420 bohr and c= 6.36 bohr. They are closer to the experimental value of a = 5.22 bohr and c= 6.48 bohr. Finally, discussing band structure and density of state of two dimensional Al(100), the electrical property of two dimensionalAl(100) is determined based on energy band gap.