pythtb.Lattice.cut_piece#

Lattice.cut_piece(num_cells, periodic_dir)[source]#

Cut a (d-1)-dimensional piece out of a d-dimensional Lattice.

Constructs a (d-1)-dimensional Lattice out of a d-dimensional one by repeating the unit cell a given number of times along one of the periodic lattice vectors. The lattice vector along which the cut is made is no longer considered periodic, but otherwise remains unchanged. Orbitals are added in the new unit cells by translating the original orbitals by integer multiples of the lattice vectors.

Parameters:
numint

How many times to repeat the unit cell.

fin_dirint

Index of the real space lattice vector along which you no longer wish to maintain periodicity.

Returns:
fin_latLattice

Object of type pythtb.Lattice representing a cutout lattice.

Notes

  • Orbitals in fin_lat are numbered so that the i-th orbital of the n-th unit cell has index i + norb * n (here norb is the number of orbitals in the original model).

  • The real-space lattice vectors of the returned model are the same as those of the original model; only the dimensionality of reciprocal space is reduced.