High-entropy materials have attracted considerable interest due to the
combination of useful properties and promising applications. Predicting their
formation remains the major hindrance to the discovery of new systems. Here we
propose a descriptor - entropy forming ability - for addressing
synthesizability from first principles. The formalism, based on the energy
distribution spectrum of randomized calculations, captures the accessibility of
equally-sampled states near the ground state and quantifies configurational
disorder capable of stabilizing high-entropy homogeneous phases. The
methodology is applied to disordered refractory 5-metal carbides - promising
candidates for high-hardness applications. The descriptor correctly predicts
the ease with which compositions can be experimentally synthesized as rock-salt
high-entropy homogeneous phases, validating the ansatz, and in some cases,
going beyond intuition. Several of these materials exhibit hardness up to 50%
higher than rule of mixtures estimations. The entropy descriptor method has the
potential to accelerate the search for high-entropy systems by rationally
combining first principles with experimental synthesis and characterization.Comment: 12 pages, 2 figure
