  The discovery of high temperature superconductivity in FeSe films on SrTiO3
substrate has inspired great experimental and theoretical interests.
First-principles density functional theory calculations, which have played an
important role in the study of bulk iron-based superconductors, also
participate in the investigation of interfacial superconductivity. In this
article, we review the calculation results on the electronic and magnetic
structures of FeSe epitaxial films, emphasizing on the interplay between
different degrees of freedom, such as charge, spin, and lattice vibrations.
Furthermore, the comparison between FeSe monolayer and bilayer films on SrTiO3
is discussed.
