The first-principles all-electron linearized augmented plane wave film method in the local density functional approximation is employed to investigate the total energy and the electronic structure of the $\mathrm{Cu}\left(001\right)c(2\times 2)\text{−}\mathrm{Pd}$ ordered surface alloy. Our energy calculations show that the slight buckling of the Pd atoms is less than $0.1\mathrm{\AA }$, which is in accord with low-energy electron diffraction and scanning tunneling microscopy observations. This slight buckling can be well understood by considering the metallic bonding between the deposited Pd and the interface Cu atoms. In addition, according to the calculated densities of states and the energy bands of $\mathrm{Cu}\left(001\right)c(2\times 2)\text{−}\mathrm{Pd}$, three features due to the incorporation of Pd are found at $-3.8$, $-1.0$, and $0.1\mathrm{eV}$ relative to the Fermi level, in agreement with the observations of the angle-resolved photoemission spectra, allowing an overall energy shift of about $0.7–1.0\mathrm{eV}$.

• Received 6 March 2004

DOI:https://doi.org/10.1103/PhysRevB.71.075406