Computation of the Cohesive Energies of NaCl, SiO2 and Al Using Density Functional Theory
Aungwa Francis *
Department of Physics, Nigerian Defence Academy, Kaduna, Nigeria
S. G. Abdu
Department of Physics, Kaduna State University, Kaduna, Nigeria
Ali Haruna
Department of Physics, Nigerian Defence Academy, Kaduna, Nigeria
Eli Danladi
Department of Physics, Nigerian Defence Academy, Kaduna, Nigeria
*Author to whom correspondence should be addressed.
Abstract
In this paper, the cohesive energies of Sodium Chloride (NaCl), Silicon dioxide (SiO2) and Alum inum (Al) based on computer code FHI-aims were calculated using Density Functional Theory. The code has several input parameters in which some of the variables were optimized. The cohesive energies of NaCl, SiO2 and Al were calculated within Local Density Approximation (LDA) of Perdew Wang of the density functional theory. The results obtained from the computation of the cohesive energies of NaCl, SiO2 and Al were 8.38 eV, 12.32 eV and 3.64 eV respectively which is in good agreement when compared to the experimental values of 8.18,12.94 and 3.39eV for NaCl, SiO2 and Al respectively. These energies are within reasonable percentage errors of 2.4%, 4.8% and 6.9% respectively.
Keywords: Total and cohesive energy, DFT, lattice constant, bulk modulus, ground state, LDA