Birefringent, Disordered, Nonmetal, Optical properties, Trigonal

• Li-Nb-O
• Ni-O
• Li-Mg-Nb-O
• Ga-La-O-Si
• Ce-F
• phonons
• refractive index
• optical absorption
• optical spectra
• wavenumber of optical phonon
• nonmetal
• birefringent
• disordered
• chalcogen
• transitional