## Embedded atom method and the Glue potential Embedded atom method basically contains/means: - embedding energy as a function of background gas density - cohesive energy of a metallic system can be expressed in terms of embedding energies and electrostatic interaction. - each atom in metal is embedded into the electron gas created by other atoms - near a defect/surface, atoms are embedded into a different density profile The form of EAM is typically: $E_{\rm coh} = \sum G \left( \sum \rho_j (R_{ij}) \right) + \frac{1}{2} \sum_{i, j,i \neq j} U_{ij}(R_{ij})$ $G$ term is embedded energy. $U$ is a 2-body $e^- - e^-$ Coulomb interaction. This method provides reasonably good accuracy. And the Glue potential: - try to describe electronic cohesion of d$e^-$, in/near noble metals. - hybridization & directional bonding are hindered - "glue" depends on local density The potential in the form $V = [\text{pair potential}] + [\text{glue}]$. $[\text{glue}]$ part is $n$ dependence, i.e., the electron, $n_{i}=\sum_{j=1}^{N} \rho_{ij}$. It only considers the local electron density. Data fitting is required to use the glue potential, for gold, the result is good.