  We screen a large chemical space of perovskite alloys for systems with the
right properties to accommodate a morphotropic phase boundary (MPB) in their
composition-temperature phase diagram, a crucial feature for high piezoelectric
performance. We start from alloy end-points previously identified in a
high-throughput computational search. An interpolation scheme is used to
estimate the relative energies between different perovskite distortions for
alloy compositions with a minimum of computational effort. Suggested alloys are
further screened for thermodynamic stability. The screening identifies alloy
systems already known to host a MPB, and suggests a few new ones that may be
promising candidates for future experiments. Our method of investigation may be
extended to other perovskite systems, e.g., (oxy-)nitrides, and provides a
useful methodology for any application of high-throughput screening of
isovalent alloy systems.
