The Zintl phase hydrides CaSiH1.3, BaSiH1.9 and SrGeH1.3 exhibit hydride anions in alkaline earth metal voids as well as hydrogen bound to the polyanions formed by silicon / germanium. The latter case is especially rare making the characterisation of this element hydrogen bond fundamental. Literature discusses it controversially from a short covalent bond to a long bonding distance with only a weak interaction. Our group's Rietveld refinement of crystal structure models using neutron powder diffraction data support the covalent picture, but the results are not unambiguous. Furthermore, the hydrogen site bound to the p-block element shows a severe non-stoichiometry and, thus, local effects become important for the structure description. A pair-distribution function (pdf) analysis directly accesses the desired bond length and, thus, helps to extend our knowledge of Zintl phase hydrides.