  High entropy oxides (HEOs) are a rapidly emerging class of functional
materials consisting of multiple principal cations. The original paradigm of
HEOs assumes cationic occupations with the highest possible configurational
entropy allowed by the composition and crystallographic structure. However, the
fundamental question remains on the actual degree of configurational disorder
in HEOs, especially, in systems with a low enthalpy barriers for cation
anti-site mixing. Considering the experimental limitations due to the presence
of multiple principal cations in HEOs, here we utilize a robust and
cross-referenced characterization approach using soft X-ray magnetic circular
dichroism, hard X-ray absorption spectroscopy, M\"ossbauer spectroscopy,
neutron powder diffraction and SQUID magnetometry to study the competition
between crystal field stabilization energy and configurational entropy
governing the cation occupation in a spinel HEO (S-HEO),
(Co$_{0.2}$Cr$_{0.2}$Fe$_{0.2}$Mn$_{0.2}$Ni$_{0.2}$)$_3$O$_4$. In contrast to
the previous studies, the derived complete structural and spin-electronic
model,
(Co$_{0.6}$Fe$_{0.4}$)(Cr$_{0.3}$Fe$_{0.1}$Mn$_{0.3}$Ni$_{0.3}$)$_2$O$_4$,
highlights a significant deviation from the hitherto assumed paradigm of
entropy-driven non-preferential distribution of cations in HEOs. An immediate
correlation of this result can be drawn with bulk as well as the local element
specific magnetic properties, which are intrinsically dictated by cationic
occupations in spinels. The real local lattice picture presented here provides
an alternate viewpoint on ionic arrangement in HEOs, which is of fundamental
interest for predicting and designing their structure-dependent
functionalities.
