▎ 摘　　要

Unlike graphene (AB) stacks, (ABC) stacks have two interesting properties: they are topological insulators with only surface states at the Fermi level, and they develop a tunable gap in an external electric field. The total energy of graphene (AB) stacks is lower than of (ABC) stacks which coincides with the empirical fact that graphite is mainly (AB) stacked. An external perpendicular electric field, however, makes (ABC) stacks energetically more favorable than (AB) stacks. Thus, growing or annealing stacks in an external electric field might become a device to increase the yield in (ABC) sequences or even to produce (ABC) stacks in a controlled way.