  The Nitrogen-Vacancy (NV) center in diamond has attractive properties for a
number of quantum technologies that rely on the spin angular momentum of the
electron and the nuclei adjacent to the center. The nucleus with the strongest
interaction is the $^{13}$C nuclear spin of the first shell. Using this degree
of freedom effectively hinges on precise data on the hyperfine interaction
between the electronic and the nuclear spin. Here, we present detailed
experimental data on this interaction, together with an analysis that yields
all parameters of the hyperfine tensor, as well as its orientation with respect
to the atomic structure of the center.
