Prediction of superconductivity in Haeckelite compounds using first-principles calculations.

Research into the superconducting characteristics of materials has intrigued scientists for an extended period. This study examines the superconductivity of 3D metallic Haeckelite compounds (XY), characterized by square-octagonal structures and P 4 2 / m n m symmetry group. Utilizing first-principles calculations, we have performed a thorough examination of the dynamic stability, electronic structures, and electron-phonon coupling (EPC) in Haeckelite structures containing elements X = B , Be , Ni , Pd , Pt , Cu and Y = C , O , Se , S , Si , Te . Our analysis indicates that 14 compounds demonstrate both mechanical and dynamic stability with superconducting transition temperatures ( T c ) ranging from ∼ 0.1 K to 15.7 K . Among these, BeC and BC exhibit the highest T c of 11.3 K and 15.7 K , respectively, with corresponding superconducting gaps of 1.8 meV and 2.4 meV . This study clarifies the relationships between electronic structures, phonon characteristics, and superconductivity in Haeckelite compounds through the application of Eliashberg equations.