This chapter focuses on recent computational studies of the electronic structure and bonding in molecular compounds of the f elements, addressing key chemical concepts such as covalency, electron counting rules, and oxidation state. A brief overview is provided of the technical considerations particular to the f block, after which, several examples of studies employing density functional theory are discussed. These have been chosen specifically to illustrate the application to the f elements of several of the techniques introduced in Volume 1: energy decomposition analysis, the electron localization function (ELF), and the quantum theory of atoms in molecules. Focus then switches to three examples of the application of multi-configurational approaches: U2, the actinyls (AnO2+/2+), and the f block metallocenes (M(η8-C8H8)2). We draw the chapter to a close with some concluding remarks.