Nuclear Resonance Determination of the Magnetic Space Group of CsMnCl3·2H2O

The Cl, Cs, and H nuclear magnetic resonance are used to examine the magnetic structure of antiferromagnetic Cs Mn Cl₃·2H₂O. The magnetic space group is $P_{\text{2b}}\mathrm{c\prime ca\prime }$ , and the structure consists of eight sublattices with the sublattice magnetization along the $b$ axis. The linear chains invoked by other authors to explain the high‐temperature anomaly in the susceptibility and specific heat are shown to be antiferromagnetic. The large intrachain exchange postulated by these authors and the rather small observed Néel temperature are shown to be reconciled by the Green's‐function theory of the Néel temperature, provided the exchange between the chains is assumed to be relatively small.