## What is/are Stacked Honeycomb?

Stacked Honeycomb - Particularly, the calculations are done on both the stacked honeycomb and the cubic lattices.^{[1]}We construct a single-phase three-dimensional structure, an analog of the AAstacked honeycomb lattice, and predict the existence of Weyl points with opposite topological charges (±1), elastic Fermi arcs, and the associated gapless topologically protected surface states.

^{[2]}Here we report on our inelastic neutron scattering investigation on large single crystals of a stacked honeycomb lattice magnet CoTiO$_3$, which is part of a broad family of ilmenite materials.

^{[3]}

## stacked honeycomb lattice

We construct a single-phase three-dimensional structure, an analog of the AAstacked honeycomb lattice, and predict the existence of Weyl points with opposite topological charges (±1), elastic Fermi arcs, and the associated gapless topologically protected surface states.^{[1]}Here we report on our inelastic neutron scattering investigation on large single crystals of a stacked honeycomb lattice magnet CoTiO$_3$, which is part of a broad family of ilmenite materials.

^{[2]}