A re-interpretation of the crystal structure of '(NH4)2(NH3)[Ni(NH3)2Cl4]' in terms of (NH4)2-2z[Ni(NH3)2]z[Ni(NH3)2Cl4]

A re-interpretation and re-evaluation of single-crystal X-ray diffraction data of a previously reported '(NH4)(2)(NH3) [Ni(NH3)(2)Cl-4]' (J- Solid State Chem. 162 (2001) 254) give a new formula (NH4)(2-2z)[Ni(NH3)(2)](z)[Ni(NH3)(2)Cl-4] with z = 0.152. This new formula results from defects in an idealized '(NH4)(2)[Ni(NH3)(2)Cl-4]' basic structure, where two adjacent NH4+ cations are replaced by one Ni(NH3)(2)(2+) unit. Cl- anions from the basic structure complete the coordination sphere of the new Ni2+ to [Ni(NH3)(2)Cl-4](2-). (C) 2003 Elsevier Inc. All rights reserved.