Chemically Defined Ln 2 H 3– x N Nitride-Hydrides via High-Pressure Synthesis and Topochemical Hydrogen Intercalation - Zefeng Wei; Hiroshi Takatsu; Hiroki Ubukata; Daichi Kato; Yu Cao; Kantaro Murayama; Tong Zhu; Cédric Tassel; Hiroshi Kageyama (Journal of the American Chemical Society, 2026)