  Topologically protected flat surface bands make thin films of rhombohedral
graphite an appealing platform for searching for strongly correlated states of
2D electrons. In this work, we study rhombohedral graphite with a twin boundary
stacking fault and analyse the semimetallic and topological properties of
low-energy bands localised at the surfaces and at the twinned interface. We
derive an effective 4-band low energy model, where we implement the full set of
Slonczewski-Weiss-McClure (SWMcC) parameters, and find the conditions for the
bands to be localised at the twin boundary, protected from the
environment-induced disorder. This protection together with a high density of
states at the charge neutrality point, in some cases -- due to a Lifshitz
transition, makes this system a promising candidate for hosting
strongly-correlated effects.
