  The discovery of iron pnictides and iron chalcogenides as a new class of
unconventional superconductors in 2008 has generated an enourmous amount of
experimental and theoretical work that identifies these materials as correlated
metals with multiorbital physics, where magnetism, nematicity and
superconductivity are competing phases that appear as a function of pressure
and doping. A microscopic understanding of the appearance of these phases is
crucial in order to determine the nature of superconductivity in these systems.
Here we review our recent theoretical efforts to describe and understand from
first principles the properties of iron pnictides and chalcogenides with
special focus on (i) pressure dependence, (ii) effects of electronic
correlation and (iii) origin of magnetism and superconductivity.
