Crystal structure and energy band and optical properties of phosphate Sr3P4O13

A single crystal of the compound Sr₃P₄O₁₃ has been found and the crystal structure has been characterized by means of single crystal X-ray diffraction analysis. The compound crystallizes in triclinic system and belongs to space group . It builds up from SrO₇ polyhedra and P₄O₁₃⁻⁶ anions and has a layered structure, and the Sr atoms are located in the interlayer space. The absorption and luminescence spectrum of Sr₃P₄O₁₃ microcrystals have been measured. The calculated results of crystal energy band structure by the DFT show that the solid state of Sr₃P₄O₁₃ is an isolator with direct band gap. The calculated total and partial density of states indicate that the top valence bands are contributions from P 3p and O 2p states and low conduction bands mostly originate from Sr atomic states. The calculated optical response functions expect that the Sr₃P₄O₁₃ is a low refractive index, and it is possible that the Sr₃P₄O₁₃ is used to make transparent material between the UV and FR light zone.