  The confluence of state-of-the-art electronic-structure computations and
modern synthetic materials growth techniques is proving indispensable in the
search for and discovery of new functionalities in oxide thin films and
heterostructures. Here, we review the recent contributions of
electronic-structure calculations to predicting, understanding, and discovering
new materials physics in thin-film perovskite oxides. We show that such
calculations can accurately predict both structure and properties in advance of
film synthesis, thereby guiding the search for materials combinations with
specific targeted functionalities. In addition, because they can isolate and
decouple the effects of various parameters which unavoidably occur
simultaneously in an experiment -- such as epitaxial strain, interfacial
chemistry and defect profiles -- they are able to provide new fundamental
knowledge about the underlying physics. We conclude by outlining the
limitations of current computational techniques, as well as some important open
questions that we hope will motivate further methodological developments in the
field.
