Hydride and nanohydride synthesis. Synthesis and handling of the air-sensitive materials were carried out under argon atmosphere using standard Schlenk and glove-box techniques. The synthesis of Li3N@(6nm PC) was performed using the general procedure described by Wood et al., but a higher Li3N loading was achieved (60% by weight). The as-synthesized LiNH2@(6-nm PC) was heated in vacuum at 340 °C to yield Li3N@(6-nm PC). Bulk lithium nitride powder (Strem) was ball-milled using the SPEX-8000 mill for 120 minutes prior to conducting Sieverts and PCT measurements.