In this paper we derive an expression for the temperature dependence of the magnetic moment of octahedral
d
5
complexes which have ligand field strengths in the neighbourhood of the
2
T
2
-
6
A
1
crossover point. The expression includes the effects of configurational mixing and of spin-orbit coupling of the low lying
4
T
1
state with the ground and first excited states. In this case the corrections are at most some 10% of the unperturbed result. Calculated results for Fe
3+
are shown to be in reasonable agreement with experimental results for the iron (III)
NN
-dialkyldithiocarbamates (Ewald, Martin, Ross & White 1964).
The silver fox / by E. OE. Somerville and Martin Ross [pseud.]