Minority carriers in graphite and the H -point magnetoreflection spectra

Analysis of the $H$-point magnetoreflection spectra of graphite is shown to be sensitive not only to the magnitude, but also to the sign of the Slonczewski-Weiss-McClure band parameter $\ensuremath{\Delta}$. The demonstration that $\ensuremath{\Delta}$ is small and negative provides a definite assignment for the larger of the minority de Haas-van Alphen periods to the Brillouin-zone corner, the $H$-point. This assignment is in good agreement with other experimental data.