  Initiated by the discovery of topological insulators, topologically
non-trivial materials have attracted immense interest in the physics community
in the past decade. One of the latest additions to the field, the material
class of topological semimetals, has grown at an extremely fast rate . While
the prototype of a topological semimetal, graphene, has been known for a while,
the first 3D analogues of graphene have only been discovered recently. This
review, written from a chemistry perspective, intends to make the growing field
of topological semimetals accessible to the wider community of materials
scientists and scholars from related disciplines. To this end, we describe key
features of topological semimetals, embedded in their electronic structure, and
how they can be achieved based on chemical principles. We introduce the
different classes of topological semimetals and review their salient
representatives. Finally, selected properties and potential applications of
these materials are discussed.
