The Cohesive Energy Calculations of Some FCC (LiCl, NaCl, RbBr, KI) Lattices Using Density Functional Theory

The cohesive energies of lithium chloride (LiCl), sodium chloride (NaCl), rubidium bromide (RbBr) and potassium iodide (KI) were computed using density functional theory (DFT). DFT based Fritz Haber Institute-ab initio molecular simulation (FHI-aims) computer code has several input parameters in which some of the variables were optimized. The cohesive energies of LiCl, NaCl, RbBr and KI were calculated within Perdew Wang local density approximations (LDA) of DFT, the results obtained from the calculations of cohesive energies of LiCl, NaCl, RbBr and KI were approximately 7.69eV, 7.23eV, 6.65eV, and 6.50eV respectively. These results obtained are in the neighborhood of experimentally found values of 8.85eV, 8.18eV, 6.90eV and 6.74 for LiCl, NaCl, RbBr and KI respectively within reasonable percentage errors.