Metastable phase access and kinetic stability in synthesized hydride superconductors

Ascertain whether experimental synthetic techniques used to produce hydride superconductors access metastable phases, and determine the kinetic (thermal) stability at finite temperatures of metastable hydride structures predicted via density functional theory-based crystal structure prediction methods.

Background

The paper highlights limitations in current discovery pipelines for hydride superconductors, including metaheuristic crystal structure prediction (CSP) methods and uncertainties in experimental synthesis pathways. While many promising hydrides are identified computationally, the relationship between these predictions and experimentally realized phases—especially metastable ones—remains uncertain.

The authors explicitly note uncertainty regarding whether synthesis routes reach metastable configurations and whether computationally predicted metastable phases possess sufficient kinetic barriers to remain stable at finite temperatures. Resolving this would clarify the reliability and relevance of computational targets for experimental efforts.