Uniaxial Orientational Order–Disorder Transitions in Diammine Magnesium Halides, Mg(ND3)2Cl2 and Mg (ND3)2Br2, Investigated by Neutron Diffraction

For magnetic solids with several unpaired spins per spin site, the average spin orbital interaction energies and the average spin orbital interaction energy squares <(e)2> were defined as a qualitative measure for the strengths of their antiferromagnetic spin exchange interactions. The trends in the antiferromagnetic spin exchange interactions of the magnetic solids containing MnF5 chains and CrX2 (X=O, S) layers were examined in terms of the and <(e)2> values calculated for their spin dimers.