  A comprehensive study of the electronic properties of monoclinic MoO2 from
both an experimental and a theoretical point of view is presented. We focus on
the investigation of the Fermi body and the band structure using angle resolved
photoemission spectroscopy, de Haas-van Alphen measurements, and electronic
structure calculations. For the latter, the new full-potential augmented
spherical wave (ASW) method has been applied. Very good agreement between the
experimental and theoretical results is found. In particular, all Fermi surface
sheets are correctly identified by all three approaches. Previous controversies
concerning additional hole-like surfaces centered around the Z- and B-point
could be resolved; these surfaces were an artefact of the atomic-sphere
approximation used in the old calculations. Our results underline the
importance of electronic structure calculations for the understanding of MoO2
and the neighbouring rutile-type early transition-metal dioxides. This includes
the low-temperature insulating phases of VO2 and NbO2, which have crystal
structures very similar to that of molybdenum dioxide and display the
well-known prominent metal-insulator transitions.
