Predicting Unconventional High-Temperature Superconductors in Trigonal Bipyramidal Coordinations

Cuprates and iron-based superconductors are two classes of unconventional high-Tc superconductors based on 3d transition elements. Recently, two principles, the correspondence principle and the magnetic selective pairing rule, have emerged to unify their high-Tc superconducting mechanisms. These principles strongly regulate electronic structures that can host high-Tc superconductivity. Guided by these principles, here, we propose high-Tc superconducting candidates that are formed by cation-anion trigonal bipyramidal complexes with a d7 filling configuration on the cation ions. Their superconducting states are expected to be dominated by the dxy±idx2−y2 pairing symmetry.