  Plasma-facing materials (PFMs) represent one of the most significant
challenges for the design of future nuclear fusion reactors. Inside the
reactor, the divertor will experience the harshest material environment:
intense bombardment of neutrons and plasma particles coupled with large and
intermittent heat fluxes. The material designated to cover this role in ITER is
tungsten (W). While no other materials have shown the potential to match the
properties of W, many drawbacks associated with its application remain,
including: cracking and erosion induced by a low recrystallization temperature
combined with a high ductile-brittle transition temperature and
neutron-initiated embrittlement; surface morphology changes (fuzz layer) due to
plasma-W interaction with subsequent risk of spontaneous material melting and
delamination; low oxidation resistance. This work aims to produce a structured
and comprehensive materials screening of PFMs candidates based on known
inorganic materials. The methodology applied in this study to identify the most
promising PFM candidates combines peer-reviewed data present in the Pauling
File database and DFT calculations of two key PFMs defects, namely the surface
binding energy and the formation energy of a hydrogen interstitial. The crystal
structures and their related properties, extracted from the Pauling File, are
ranked according to the heat-balance equation of a PFM subject to the heat
loads in the divertor region of an ITER-like tokamak. The materials satisfying
the requirements are critically compared with the state-of-the-art literature,
defining an optimal subset where to perform the first-principles electronic
structure calculations. The majority of previously known PFMs are captured by
this screening process, confirming its reliability. Additionally, less familiar
refractory materials suggest performance that calls for further investigations.
