  The electronic structure of the enigmatic iron-based superconductor FeSe has
puzzled researchers since spectroscopic probes failed to observe the expected
electron pocket at the $Y$ point in the 1-Fe Brillouin zone. It has been
speculated that this pocket, essential for an understanding of the
superconducting state, is either absent or incoherent. Here, we perform a
theoretical study of the preferred nematic order originating from
nearest-neighbor Coulomb interactions in an electronic model relevant for FeSe.
We find that at low temperatures the dominating nematic components are of
inter-orbital $d_{xz}-d_{xy}$ and $d_{yz}-d_{xy}$ character, with spontaneously
broken amplitudes for these two components. This inter-orbital nematic order
naturally leads to distinct hybridization gaps at the $X$ and $Y$ points of the
1-Fe Brillouin zone, and may thereby produce highly anisotropic Fermi surfaces
with only a single electron pocket at one of these momentum-space locations.
The associated superconducting gap structure obtained with the generated
low-energy electronic band structure from spin-fluctuation mediated pairing
agrees well with that measured experimentally. Finally, from a comparison of
the computed spin susceptibility to available neutron scattering data, we
discuss the necessity of additional self-energy effects, and explore the role
of orbital-dependent quasiparticle weights as a minimal means to include them.
