2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/90709We discuss the results of computer model for the thermal emissivity of a three-dimensional photonic band gap (PBG) crystal, specifically an inverted opal structure. The thermal emittance for a range of frequencies and angles is calculated.4 pages, 4 figs, RevTex4Quantum Physicstext