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Quantum dots (QD) are very small semiconductor particles, only several nanometres in size, so small that their optical and electronic properties differ from those of larger particles. They are a central theme in nanotechnology.
These species may not be so well represented by a single Lewis dot structure because the species itself does not stay in one configuration. Lewis dot diagrams give us a static picture of what the molecule or ion might look like. So how do we deal with situations were a static model does not tell us the entire story. We assume that we can represent each different configuration by a Lewis dot structure and in some cases, all these different diagrams add to our overall understanding of the real species. There are two different ways that we might find multiple Lewis dot structures: Lewis dot diagrams displaying higher than optimal formal charges represent higher energy states of the species. There may be several ways to draw the optimal configuration Lewis dot diagram, which could mean that the ground-state electrons are not fixed into local orbitals.