Common geometries (sisl.geom)

A variety of default geometries.

Basic

sisl.geom.sc(alat, atom)[source]

Simple cubic lattice with 1 atom

Parameters
alatfloat

lattice parameter

atomAtom

the atom in the SC lattice

sisl.geom.bcc(alat, atom, orthogonal=False)[source]

Body centered cubic lattice with 1 (non-orthogonal) or 2 atoms (orthogonal)

Parameters
alatfloat

lattice parameter

atomAtom

the atom in the BCC lattice

orthogonalbool, optional

whether the lattice is orthogonal (2 atoms)

sisl.geom.fcc(alat, atom, orthogonal=False)[source]

Face centered cubic lattice with 1 (non-orthogonal) or 4 atoms (orthogonal)

Parameters
alatfloat

lattice parameter

atomAtom

the atom in the FCC lattice

orthogonalbool, optional

whether the lattice is orthogonal (4 atoms)

sisl.geom.hcp(a, atom, coa=1.63333, orthogonal=False)[source]

Hexagonal closed packed lattice with 2 (non-orthogonal) or 4 atoms (orthogonal)

Parameters
alatfloat

lattice parameter

atomAtom

the atom in the HCP lattice

orthogonalbool, optional

whether the lattice is orthogonal (4 atoms)

2D materials

sisl.geom.honeycomb(bond, atom, orthogonal=False)[source]

Honeycomb lattice with 2 or 4 atoms per unit-cell, latter orthogonal cell

This enables creating BN lattices with ease, or graphene lattices.

Parameters
bondfloat

bond length between atoms (not lattice constant)

atomAtom

the atom (or atoms) that the honeycomb lattice consists of

orthogonalbool, optional

if True returns an orthogonal lattice

See also

graphene

the equivalent of this, but with default of Carbon atoms

sisl.geom.graphene(bond=1.42, atom=None, orthogonal=False)[source]

Graphene lattice with 2 or 4 atoms per unit-cell, latter orthogonal cell

Parameters
bondfloat

bond length between atoms (not lattice constant)

atomAtom, optional

the atom (or atoms) that the honeycomb lattice consists of. Default to Carbon atom.

orthogonalbool, optional

if True returns an orthogonal lattice

See also

honeycomb

the equivalent of this, but with non-default atoms

Nanotube

sisl.geom.nanotube(bond, atom=None, chirality=(1, 1))[source]

Nanotube with user-defined chirality.

This routine is implemented as in ASE with some cosmetic changes.

Parameters
bondfloat

length between atoms in nano-tube

atomAtom(6)

nanotube atoms

chirality(int, int)

chirality of nanotube (n, m)

Others

sisl.geom.diamond(alat=3.57, atom=None)[source]

Diamond lattice with 2 atoms in the unitcell

Parameters
alatfloat

the lattice constant for the diamond

atomAtom, optional

atom in the lattice, may be one or two atoms. Default is Carbon