Room-temperature phosphorescence (RTP) has generated significant interest among experimental and computational scientists due to its wide range of applications, including its use in highly emissive materials for organic light-emitting diodes (OLEDs), anti-counterfeiting, photovoltaic devices, and bioimaging. Since efficient phosphorescence requires a substantial triplet population, these materials have traditionally been designed using inorganic and organometallic compounds that promote intersystem crossing (ISC) via strong spin-orbit coupling (SOC) and charge-transfer mechanisms. In contrast, organic molecules, due to their relatively small triplet populations and competing nonradiative pathways, typically exhibit phosphorescence only at cryogenic temperatures and under inert conditions in solution. However, recently RTP has been achieved in several purely organic crystals composed of molecules with relatively simple structures. These organic materials are significantly more cost-effective and environmentally friendly than their inorganic and organometallic counterparts.