Stability and bonding nature of clathrate H cages in a near-room-temperature superconductor <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>LaH</mml:mi><mml:mn>10</mml:mn></mml:msub></mml:math>

Lanthanum hydride (${\mathrm{LaH}}_{10}$) with a sodalitelike clathrate structure was experimentally synthesized to exhibit near-room-temperature superconductivity under megabar pressures. Based on first-principles density-functional theory calculations, we reveal that the metal framework of La atoms has excess electrons at interstitial regions. Such anionic are easily captured form stable H cages. We thus propose charge transfer from is mostly driven by electride property framework. Furthermore, interaction between atom and cage induces delocalization $5p$ semicore states hybridize $1s$ state. Consequently, bonding nature ${\mathrm{LaH}}_{10}$ characterized as mixture ionic covalent cage. Our findings demonstrate play important roles in stabilizing cages ${\mathrm{LaH}}_{10}$, which can be broadly applicable other compressed rare-earth hydrides structures.