Bis[aminoguanidinium(1+)] hexafluorozirconate(IV): redeterminations and normal probability analysis

The crystal structure of bis[aminoguanidinium(1+)] hexafluorozirconate(IV), (CH(7)N(4))(2)[ZrF(6)], originally reported by Bukvetskii, Gerasimenko & Davidovich [Koord. Khim. (1990), 16, 1479-1484], has been redetermined independently using two different samples. Normal probability analysis confirms the reliability of all refined parameter standard uncertainties in the new determinations, whereas systematic error detectable in the earlier work leads to a maximum difference of 0.069 (6) A in atomic positions between the previously reported and present values of an F-atom y coordinate. Radiation-induced structural damage in aminoguanidinium polyfluorozirconates may result from minor displacements of H atoms in weak N-H...F bonds to new potential minima and subsequent anionic realignment.