A quantitative estimation of quantum discord is performed for a Heisenberg spin 1/2 dimer compound (NH 4 CuPO 4, H 2 O) by means of experimental magnetic and thermal measurements. Magnetic susceptibility and specific heat data were collected for NH 4 CuPO 4, H 2 O and analyzed within the framework of the Heisenberg isolated dimer model. Internal energy as a function of temperature is obtained by integrating the specific heat versus temperature data. Subsequently, quantum discord, total correlations and spin–spin correlation function are quantified from susceptibility and internal energy and plotted as a function of temperature. Violation of Bell's inequality is also tested for NH 4 CuPO 4, H 2 O via both experimental susceptibility and specific heat data signifying the presence of entanglement.