Abstract
Extended covalent compounds that contain gold are virtually unknown because Au prefers metallic or molecular coordination. Using crystal structure search combined with first-principles calculations at high pressure, we have identified a family of ternary compounds, M(2)AuB(6) (M = Na, K, Mg, Ca, and Sr), featuring Au-B covalent frameworks that satisfy a simple "push-pull" design rule: strongly electropositive cations donate charge that anchors Au in electron-deficient B(6) octahedra, thereby stabilizing Au-B σ bonds through Au dsp(2) hybridization. The low enthalpy phases, Na(2)AuB(6) and K(2)AuB(6), exhibit superconductivity, with Au-6p(x)/6p(y) and B-2p states contributing to Cooper pair formation, facilitated by low- and medium-frequency phonons arising from Au-B bond stretching. These pressure-induced structures and bonding configurations can be quenched to ambient pressure, demonstrating an effective approach to bypassing traditional electronegativity constraints. We propose M(2)AuB(6) compounds as realistic and chemically unique platforms for exploring gold-based superconductivity and for testing electron-donor-guided materials discovery.