Birefringent, Oxide, Transitional, Optical properties, Trigonal

• Li-Nb-O
• Ni-O
• Li-Mg-Nb-O
• O-Pb-Zr
• phonons
• optical spectra
• optical absorption
• wavenumber of optical phonon
• refractive index
• transitional
• birefringent
• oxide
• chalcogen
• disordered