We present a methodology for the investigation of dislocation energetics in
segregated alloys based on Monte Carlo simulations which equilibrate the
topology and composition of the dislocation core and its surroundings. An
environment-dependent partitioning of the system total energy into atomic
contributions allows us to link the atomistic picture to continuum elasticity
theory. The method is applied to extract core energies and radii of 60 degrees
glide dislocations in segregated SiGe alloys which are inaccessible by other
methods.Comment: 5 pages, to be published in Physical Review Letter