  Quantum dots (QDs) are applied in a variety of fields ranging from
photovoltaics to biomedical imaging. Even the smallest QDs present a
complicated potential energy surface characterized by a large set of stationary
points. Each local minimum is an isomer of QD of given composition. An
established theoretical methodology is hereby employed to obtain geometries of
the QD isomers (Cd16Se16, Cd16Se16, Zn16S16, Zn16Se16) and predict their
fundamental electronic and thermodynamic properties. Significantly scattered
heats of formation, with an amplitude up to 1304 kcal mol-1 in Cd16S16, were
found for the most and the least thermodynamically stable isomers of QDs. The
most shallow transition points can unlikely be observed in the experiments at
finite temperature, since they are able to transform into more stable isomers
upon thermal motion. Dipole moment is the most sensitive property to the QD
isomer geometry. A global energy search technique was demonstrated to be an
efficient tool to systematically identify isomers of QDs.
