Glycine-sodium nitrate, C2H5N2NaO5 (GSN), crystals were grown from aqueous solutions by slow cooling with a temperature lowering rate of 1 °C/day in the range of 40-22 °C. These crystals were analyzed by differential thermal and thermogravimetric analysis (DTA-TGA) and mechanical hardness tester in order to obtain their thermal and mechanical properties. Mechanical characterization was done by studying the variation of microhardness with applied load. The dielectric properties of GSN were calculated by using the CASTEP code within the framework of the generalized gradient approximation (GGA). For better understanding of the optical properties of GSN, the second derivative of ε2(E) was evaluated. DTA-TGA analysis showed that the material has a thermal stability up to 198 °C. The microhardness test was carried out for several faces of GSN crystals, and the tests revealed a load dependence to hardness. Analysis of the second derivative of ε2(E) allowed to obtain better resolution of the electronic transitions involving the energy bands. Besides, a theoretical representation of the orbitals' energy diagram was obtained. A discussion about the relation of structure-properties and molecular character of GSN is presented here. © 2008 Elsevier Ltd. All rights reserved.