Theoretical evidence for the Peierls transition in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>NbO</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>

We show by advanced electronic structure calculations that ${\mathrm{NbO}}_{2}$ essentially is a Peierls-type material. After simulating the rutile as well body-centered tetragonal phase with Bethe-Salpeter equation, we are able to reproduce experimental values for properties without adding correlations. Our calculation includes only excitonic corrections and no further interactions. The principal indirect gap between $N$ $\mathrm{\ensuremath{\Gamma}}$ found be 0.98 eV, direct at point amounts 1.35 eV. anisotropic, nesting vectors in Fermi surfaces $\mathrm{\ensuremath{\Gamma}}MAZ$ $\mathrm{\ensuremath{\Gamma}}XRZ$ planes.