Correlation of Zero Field Splittings and Site Distortions Interstitial Incorporation of Mn 2+ in Urea‐Ammoniumchloride (H 2 N) 2 CO · NH 4 Cl

In (H 2 N) 2 CO · NH 4 Cl single crystals doped with Mn 2+ three crystallographically inequivalent sets of EPR spectra with relative intensities of 8:3:2 are observed and analyzed. The second order zero field splitting parameters b 0 2 = ‐744.7; ‐712.2; ‐736.5 and b 2 2 = ‐127.1; ‐160.8; ‐111.2 (all in 10 −4 cm −1 ) and the directions of their principal axes can only be explained by incorporation of Mn 2+ into interstitial sites midway between two NH 4 sites with two water molecules replacing these ammonium ions in close analogy to NH 4 Cl:Mn.