Alkali, Chalcogen, Orthorhombic, Real part of permittivity

• Na-Nb-O
• As-H-N-O-Rb
• H-Li-N-O-S
• Bi-Na-Nb-O-Sr
• Ba-F-K-O-Ti
• chalcogen
• alkali
• nonmetal
• ferroelectric
• transitional