Quantum-chemical modeling of dispersed systems with the yttrium aluminum garnet base

Laser material Y3Al5O12 (YAG), originally known in the form of a single-crystal, has been distributed and widely commercialized in the form of optical ceramics. The desire to expand the functionality of materials made of nanocrystals due to the size effect actualizes the study of the influence of their structure on the optical (vibrational and electronic) and other properties of new promising materials with the YAG base including glass ceramics. In this work, models of crystalline alumina-iodine garnet fragments have been calculated by DFT/uPBEPBE/SDD, DFT/uPBEPBE/lanl2DZ, and DFT/uB3PW91/SDD methods. The IR spectra were calculated by DFT/uPBEPBE/lanl2DZ method and the absorption bands of the calculated wave numbers were correlated with the measured ones. The electronic absorption spectrum and energy levels were calculated by the DFT/RB3PW91/SDD method.