  The exceptional properties observed in complex concentrated alloys (CCAs)
arise from the interplay between crystalline order and chemical disorder at the
atomic scale, complicating a unique determination of properties. In contrast to
conventional alloys, CCA properties emerge as distributions due to varying
local chemical environments and the specific scale of measurement. Currently
there are few ways to quantitatively define, track, and compare local alloy
compositions (versus a global label, i.e. equiatomic) contained in a CCA.
Molecular dynamics is used here to build descriptive metrics that connect a
global alloy composition to the diverse local alloy compositions that define
it. A machine-learned interatomic potential for MoNbTaTi is developed and we
use these metrics to investigate how property distributions change with
excursions in global-local composition space. Short-range order is examined
through the lens of local chemistry for the equiatomic composition,
demonstrating stark changes in vacancy formation energy with local chemistry
evolution.
