A new alkali metal-rare earth polyphosphate CsSm(PO3)(4) has been synthesized by flux method. The obtained compound has been characterized by means of single crystal X-ray diffraction, Fourier transform infrared (FTIR) and Raman scattering spectroscopies. It crystallizes in the monoclinic space group P2(1)/n with the following unit-cell parameters: a=10.382(2), b=8.978(6), c=11.205(4) angstrom, beta=106.398(3)degrees and Z=4. The structure of CsSm(PO3)(4) is an infinite three-dimensional framework made up of double spiral (PO3)(n) chains linked with neighboring SmO8 and CsO11 polyhedra. Spectroscopic properties of Sm3+ in this new compound including excitation, emission, and kinetic measurement have been performed. The emission spectrum shows four transitions characteristics of Sm3+ in the orange-red region by excitation wavelength at 400 nm. The decay time curve of (4)G(5/2) -> H-6(7/2) transition has been also registered and fitted to a single exponential function. (C) 2014 Elsevier Ltd. All rights reserved.