The perovskite structure is one of the most fascinating configurations existing in nature, with its physical and chemical properties heavily influenced by the nature and oxidation states of cations, stoichiometry, and crystalline structure. Layered perovskite material K4Xe3O12, an interesting member of this family, possesses energetic properties that require detailed investigation. To establish the governing principles and quantify the observed behaviors, a detailed computational investigation is conducted into the electronic, vibrational, structural, and optical characteristics of K4Xe3O12, utilizing Density Functional Theory (DFT) calculations. The calculated elastic constants adhere to Born's criteria, affirming the mechanical stability of trigonal K4Xe3O12, with a bulk modulus (Bo) of ≈53.93 GPa. This low compressibility is intricately tied to its robust perovskite structure, featuring XeO6 octahedra sandwiched between XeO3 molecules. Precise determination of the valence‐conduction bandgap is crucial for understanding potential connections to the photodecomposition phenomenon. Using the Tran‐Blaha‐modified Becke‐Johnson (TB‐mB) potential alongside traditional generalized gradient approximation (GGA) approach, a bandgap of ≈1.32 eV is determined. Rapid fluctuations in optical properties also suggest a propensity for photodecomposition in the visible spectrum. The study provides critical insights into perovskite materials, especially those containing noble gas atoms, unveiling unique chemical and physical properties that open up new avenues for versatile applications across various fields.
