Gum-actinium p-nitrophenolate (GUNP), a novel organic compound, was synthesized and crystals were grown from methanol solution by a slow evaporation solution growth technique. A single crystal X-ray diffraction study elucidated the crystal structure of GUNP belonging to the orthorhombic crystal system with space group Pnma. Thermal studies revealed that the GUNP crystal is thermally stable up to 192 C. The lower cut-off wavelength of GUNP was found to be 505 nm by UV-vis-NIR spectral studies. The luminescence properties of the GUNP crystal were investigated. The three independent tensor coefficients epsilon(11), epsilon(22) and epsilon(33) of the dielectric permittivity were calculated. The mechanical properties of the grown crystal were studied by Vickers' microhardness hardness technique. (C) 2014 Elsevier B.V. All rights reserved,