FTIR, FT-Raman and NMR are studied to explore the functional groups, the vibration modes and its coupling interactions for the grown single crystal piperazine-1,4-diium bis (4-aminobenzenesulfonate) (PABS). The cut-off wavelength at 303 nm of UV–Visible spectrum exhibits great transmittance over the entire visible spectrum. Photoluminescence spectral study revealed the electron excitation notably in blue emission range. The range of susceptibility and nonlinear refractive index was obtained from second and third harmonic generations of PABS crystals. At various temperatures, the thermal stability of the crystal and the crystal dielectric characteristics had been studied in relation to frequency. The hardness of the crystal was obtained by microhardness measurements.