Theoretical research of electronic, optical, and vibrational properties of nonlinear Li2K4TiOGe4O12 crystal

https://doi.org/10.1016/j.physb.2025.417507

The density functional theory simulations of the electronic band structure of the Li2K4TiOGe4O₁₂ crystal of the tetragonal phase were carried out along the high-symmetry directions of the Brillouin zone. The simulation partial density of states of the crystal in the P4nc phase was performed to describe the origin of the electronic bands. The optical linear (dielectric function, conductivity, refractive index, absorption, loss function, and reflectivity) and nonlinear properties of the crystal (susceptibility tensor elements) were calculated. The article compares the properties of this crystal with those of other nonlinear crystals. The dispersion of phonons and Raman spectrum were also calculated, and the stability of the crystal phase was demonstrated.