bilayer

sisl.geom.bilayer(bond=1.42, bottom_atoms=None, top_atoms=None, stacking='AB', twist=(0, 0), separation=3.35, ret_angle=False, layer='both')

Commensurate unit cell of a hexagonal bilayer structure, possibly with a twist angle.

This routine follows the prescription of twisted bilayer graphene found in [9].

Notes

This routine may change in the future to force some of the arguments.

Parameters:
  • bond (float, optional) – bond length between atoms in the honeycomb lattice

  • bottom_atoms (Atom, optional) – atom (or atoms) in the bottom layer. Defaults to Atom(6)

  • top_atoms (Atom, optional) – atom (or atoms) in the top layer, defaults to bottom_atom

  • stacking ({'AB', 'AA', 'BA'}) – stacking sequence of the bilayer, where XY means that site X in bottom layer coincides with site Y in top layer

  • twist (tuple of int, optional) – integer coordinates (m, n) defining a commensurate twist angle

  • separation (float, optional) – distance between the two layers

  • ret_angle (bool, optional) – return the twist angle (in degrees) in addition to the geometry instance

  • layer ({'both', 'bottom', 'top'}) – control which layer(s) to return

See also

honeycomb

honeycomb lattices

graphene

graphene geometry