Anovelquaternarymetalselenide,K_2CdSnSe_4,wassynthesizedviaamolten-saltreactionat550℃.Thecompoundhasaone-dimensionalstructurecontainingachainof_∞~1[CdSnSe_4]~(2-)anionsseparatedbyK~+cations.ThecrystalbelongstothespacegroupI-42m,withtheunitcellparametersa=0.80298(11)nm,b=0.80298(11)nm,c=0.69217(14)nm,α=β=γ=90°.Areflectancespectroscopystudyrevealsthenatureofthesemiconductorwithanenergygapof1.7eVforthecompoundandithasastrongopticalabsorptioninarangeof2—5eV.