  We report a detailed Shubnikov-de Haas (SdH) study on the Weyl type-II
semimetal WTe2 in magnetic fields up to 29 T. By using the SdH results to guide
our density functional theory calculations, we are able to accurately determine
its Fermi surface by employing a moderate Hubbard U term, which is an essential
step in explaining the unusual electronic properties of this much studied
material. In addition to the fundamental orbits, we observe magnetic breakdown,
which can consistently be explained within the model of a Russian-doll-nested
Fermi surface of electron and hole pockets. The onset of magnetic breakdown in
WTe2 is solely determined by impurity damping in contrast to magnetic breakdown
scenarios in other metallic systems.
