Quantum Hydrogen on Graphene
Quantum mechanics tells us that lighter elements, such as hydrogen, are delocalised in space. State of the art simulation techniques treat this delocalisation, representing a single hydrogen atom by multiple coupled replicas. The more spread out the replicas, the more quantum mechanical the hydrogen atom is said to be. The hexagonal green surface is graphene, a single atomic layer of graphite.
Image by Erlend Davidson (Thomas Young Centre, London)