  Honeycomb structures formed by the growth of perovskite 5d transition metal
oxide heteroestructures along the (111) direction in $t_{2g}^5$ configuration
can give rise to topological ground states characterized by a topological index
$\nu$=1. Using a combination of a tight binding model and ab initio
calculations we study the multilayers $(\text{SrTiO}_3)_7/(\text{SrIrO}_3)_2$
and $(\text{KTaO}_3)_7/(\text{KPtO}_3)_2$ as a function of parity asymmetry,
on-site interaction and uniaxial strain and determine the nature and evolution
of the gap. $(\text{SrTiO}_3)_7/(\text{SrIrO}_3)_2$ is found to be a
topological semimetal. $(\text{KTaO}_3)_7/(\text{KPtO}_3)_2$ is a topological
Mott insulator that can be driven to a trivial insulating phase by an external
electric field.
