Alloy work functions: Extended Hückel calculations for Ag–Au and Cu–Au clusters

Extended Hückel molecular orbital theory is used to calculate the ionization potentials of Cu, Ag, Au, Ag–Au, and Cu–Au fcc clusters as large as 135 atoms. In Ag–Au and Cu–Au alloys, the ionization potential increases with increasing Au content. The effect of d orbitals on the ionization potentials of 43‐atom Ag–Au clusters is examined. In certain cases the calculated ionization potentials show variation with alloy composition similar to that of work function experiments on bulk samples.