Abstract
The interaction between halogen species and metal surfaces plays a crucial role in numerous surface-driven processes. The adsorption behavior and thermodynamic stability of bromine (Br) atoms on the Cu(100) surface using density functional theory (DFT) with van der Waals (vdW) corrections and ab initio atomistic thermodynamics is investigated. Surface adsorption was analyzed across three high-symmetry sites-top, bridge, and hollow-at various coverages from (0.11 to 1.00) ML. van der Waals forces significantly influence binding energy, particularly at low coverage. Hollow sites are identified as the most energetically favorable. The hollow site emerged as the most energetically favorable across most coverages, with the 0.75 ML configuration being particularly stable. Electronic density of states (DOS) analysis revealed strong Br-Cu hybridization and significant alterations in the Cu(3d) and Br(4p) states, especially at higher coverages. Thermodynamic phase diagrams demonstrated that increasing Br chemical potential leads to progressively more stable Br/Cu(100) surface configurations, shifting from clean Cu to partial and then full monolayer adsorption.