New functional materials of metal chalcophosphates have been receiving increasing attention due to their wide structural diversity and technologically promising properties.In this work,a quaternary selenophosphate,Cs2ZnP2Se6,has been successfully prepared by the high-temperature solid state reactions with a modified reactive CsCl flux.Single-crystal X-ray diffraction analyses show that Cs2ZnP2Se6 crystallizes in triclinic space groupP1 with a = 7.66000(10),b = 7.712(7),c = 12.7599(3)?,a = 96.911(18)°,β= 104.367(14)°,y = 109.276(13)°,V = 672.16 ?3 and Z = 2.The major structure feature is the one-dimensional(1D)chain comprised of alternating units of tetrahedrally coordinated Zn2+ions to the ethane-like[P2Se6]4-units,in which counterbalanced Cs cations are accommodated.Significantly,photo-electrochemical measurement indicated that the title compound was photo-responsive under visible-light illumination.Moreover,the optical gap of 2.67 eV for Cs2ZnP2Se6 was deduced from the UV/vis reflectance spectroscopy and theoretical calculation shows an indirect band gap with an electronic transfer excitation of Se-4p to Zn-3d/4p and P-3p orbitals.This work presents not only a novel potential application of metal chalcophosphates,but also a facile approach to prepare alkali metal-containing chalcogenides.