  High-throughput ab-initio calculations, cluster expansion techniques and
thermodynamic modeling have been synergistically combined to characterize the
binodal and the spinodal decompositions features in the pseudo-binary lead
chalcogenides PbSe-PbTe, PbS-PbTe, and PbS-PbSe. While our results agree with
the available experimental data, our consolute temperatures substantially
improve with respect to previous computational modeling. The computed phase
diagrams corroborate that the formation of spinodal nanostructures causes low
thermal conductivities in these alloys. The presented approach, making a
rational use of online quantum repositories, can be extended to study
thermodynamical and kinetic properties of materials of technological interest.
