Orbital mixing in solids as a descriptor for materials mapping

• A new method for material characterization is presented, improving upon the concept of “material maps”.
• Different functional materials are distinguished by falling into different areas of such maps.
• The novel approach is able to discern polymorphs, adding structural information to such maps for the first time.
• The maps are created fully quantum-mechanically from first-principles plane-wave/PAW DFT output.

The creation of “maps” for solid-state materials has a long-standing history in condensed matter theory. Here, based on periodic density-functional theory (DFT) output, a heuristic numerical indicator is constructed to assess s–p orbital mixing in materials (or, depending on one׳s viewpoint, the tendency toward “sp3 hybridization”). Other than before, this now intrinsically includes structural information and the microscopic effects associated with it. The new method provides useful insights to understand physical relationships in composition space and promises to help to identify hitherto unknown material candidates.