KCu2NbSe4 oS32 40

• Cu-K-Nb-S-Ta
• Cu-K-S-V
• Cu-K-Se-Ta
• Cu-Na-Nb-S
• Ag-K-Nb-Se
• structural properties
• optical properties
• phonons
• wavenumber of optical phonon
• electronic energy gap
• transitional
• chalcogen
• alkali
• sulfide
• non-disordered
• orthorhombic
• monoclinic