We investigate the effect of short-range order (SRO) on
the electronic structure in alloys from the theoretical point of view
using density of states (DOS) data. In particular, the interaction
between the atoms at different lattice sites is affected by chemical
disorder, which in turn is reflected in the fine structure of the DOS
and, hence, in the outcome of spectroscopic measurements. We aim at
quantifying the degree of potential SRO with a proper parameter.

The
theoretical modeling is done with the Korringa–Kohn–Rostoker Green's
function method. Therein, the extended multi-sublattice non-local
coherent potential approximation is used to include SRO. As a model
system, we use the binary solid solution Ag _c Pd_1−c at three representative concentrations c  =  0.25,
0.5 and 0.75. The degree of SRO is varied from local ordering to local
segregation through an intermediate completely uncorrelated state. We
observe some pronounced features, which change over the whole energy
range of the valence bands as a function of SRO in the alloy. These
spectral variations should be traceable in modern photoemission
experiments.