The title compound, C(2)H(10)N(2) (2+)·2HC(4)O(4) (-)·H(2)O, a new polymorph of ethyl-enediammonium bis-(hydrogen squarate) monohydrate, was synthesized by slow evaporation of an acid solution. The asymetric unit contains two hydrogen squarate anions, two half-mol-ecules of protonated ethyl-enediamine arranged around a twofold axis and one water mol-ecule. In the crystal, N-H⋯O and O-H⋯O hydrog...

Using examples from SiGe solid solutions grown onto (001)Si substrates from metallic solutions (liquid phase epitaxy) we discuss the different mechanisms by which misfitting systems can relax the strain caused by pseudomorphic growth. We treat elastic, plastic and diffusive relaxation and their interdependence. As an extension we discuss additional relaxation mechanisms, though possibly not ver...