An accurate indicator for unconventional superconductivity using charge-spin coupling*

A data-based prediction model for unconventional superconductivity is constructed, which has three ingredients: a layered crystal structure, stable local magnetic moments and an intermediate spin-orbital (as opposed to spin-orbit) coupling. This classifier is sufficiently specific to clearly distinguish cuprate and iron-based superconductors from other materials in the same structural class. We discuss some of the putative false positives and whether they might be good candidates for new unconventional superconductors.