UnrolledSWNTGenerator

class sknano.generators.UnrolledSWNTGenerator(*args, autogen=True, finalize=True, **kwargs)

Bases: sknano.generators.NanoStructureGenerator, sknano.core.structures.UnrolledSWNT

Class for generating unrolled nanotube structures.

New in version 0.2.23.

Parameters:

• m (n,) – Chiral indices defining the nanotube chiral vector $\mathbf{C}_{h} = n\mathbf{a}_{1} + m\mathbf{a}_{2} = (n, m)$.
• ny, nz (nx,) – Number of repeat unit cells in the $x, y, z$ dimensions
• basis ({list}, optional) –

  List of strs of element symbols or atomic number of the two atom basis (default: [‘C’, ‘C’])

  New in version 0.3.10.

• element2 (element1,) –

  Element symbol or atomic number of basis Atom 1 and 2

  Deprecated since version 0.3.10: Use basis instead

• bond (float, optional) – $\mathrm{a}_{\mathrm{CC}} =$ distance between nearest neighbor atoms. Must be in units of Angstroms.
• Ly, Lz (Lx,) –

  Length of bundle in $x, y, z$ dimensions in Angstroms. Overrides the $n_x, n_y, n_z$ cell values.

  Changed in version 0.4.0: Changed units from nanometers to Angstroms

• fix_Lz (bool, optional) – Generate the nanotube with length as close to the specified $L_z$ as possible. If True, then non integer $n_z$ cells are permitted.
• autogen (bool, optional) – if True, automatically call generate.
• verbose (bool, optional) – if True, show verbose output

Notes

The UnrolledSWNTGenerator class generates graphene using the nanotube unit cell defined by the chiral vector $\mathbf{C}_{h} = n\mathbf{a}_{1} + m\mathbf{a}_{2} = (n, m)$. If you want to generate graphene with an armchair or zigzag edge using length and width parameters, see the GrapheneGenerator class.

See also

GrapheneGenerator

Examples

First, load the UnrolledSWNTGenerator class.

>>>

>>> from sknano.generators import UnrolledSWNTGenerator

Now let’s generate an unrolled $\mathbf{C}_{\mathrm{h}} = (10, 5)$ SWCNT unit cell.

>>>

>>> unrolled_swnt = UnrolledSWNTGenerator(10, 5)
>>> unrolled_swnt.save()

The rendered structure looks like:

Attributes

Ch	SWNT circumference $|\mathbf{C}_h|$ in Å
Ch_vec	SWNT chiral vector.
Lx	Axis-aligned length along the x-axis in Angstroms.
Ly	Axis-aligned length along the y-axis in Angstroms.
Lz	SWNT length $L_z = L_{\mathrm{tube}}$ in Angstroms.
M	$M = np - nq$
N	Number of graphene hexagons in nanotube unit cell.
Natoms	N atoms.
Natoms_per_layer	Number of atoms per layer.
Natoms_per_tube	Number of atoms in nanotube $N_{\mathrm{atoms/tube}}$.
Natoms_per_unit_cell	Number of atoms in nanotube unit cell.
R	Symmetry vector $\mathbf{R} = (p, q)$.
T	Length of nanotube unit cell $|\mathbf{T}|$ in Å.
Tvec	SWNT translation vector.
area	Total area of graphene supercell.
atoms	Structure Atoms.
basis	NanoStructureBase basis objects.
chiral_angle	Chiral angle $\theta_c$ in degrees.
chiral_type	SWNT chiral type.
crystal_cell	Structure CrystalCell.
d	$d=\gcd{(n, m)}$
dR	$d_R=\gcd{(2n + m, 2m + n)}$
dt	Nanotube diameter $d_t = \frac{|\mathbf{C}_h|}{\pi}$ in Å.
electronic_type	SWNT electronic type.
element1	Basis element 1
element2	Basis element 2
fix_Lx	bool indicating whether UnrolledSWNTMixin.Lx is fixed or calculated.
fix_Lz	bool indicating whether SWNTMixin.Lz is fixed or calculated.
fmtstr	Format string.
lattice	Structure Crystal3DLattice.
lattice_shift	Lattice displacement vector.
linear_mass_density	Linear mass density of nanotube in g/Å.
m	Chiral index $m$.
mass	Total mass of atoms.
n	Chiral index $n$.
n1	Number of unit cells along Crystal3DLattice.a1.
n2	Number of unit cells along Crystal3DLattice.a2.
nlayers	Number of layers.
nx	Number of unit cells along the $x$-axis.
ny	An alias for UnrolledSWNTMixin.nlayers.
nz	Number of nanotube unit cells along the $z$-axis.
r1	Vector GrapheneMixin.n1 $\times$ Crystal3DLattice.a1.
r2	Vector GrapheneMixin.n2 $\times$ Crystal3DLattice.a2.
rt	Nanotube radius $r_t = \frac{|\mathbf{C}_h|}{2\pi}$ in Å.
scaling_matrix	CrystalCell.scaling_matrix.
structure	An alias to self.
t1	$t_{1} = \frac{2m + n}{d_{R}}$
t2	$t_2 = -\frac{2n + m}{d_R}$
tube_length	Alias for SWNT.Lz
tube_mass	An alias for mass.
unit_cell	Structure UnitCell.
unit_cell_mass	Unit cell mass in atomic mass units.
unit_cell_symmetry_params	Tuple of SWNT unit cell symmetry parameters.
vdw_distance	Van der Waals distance.
vdw_radius	Van der Waals radius

Methods

clear()	Clear list of StructureMixin.atoms.
finalize()	Finalize structure data by assigning unique ids and types to structure atoms.
generate([finalize])	Generate structure data.
generate_fname([n, m, nx, nz, fix_Lx, fix_Lz])
generate_unit_cell()	Generate the nanotube unit cell.
make_supercell(scaling_matrix[, wrap_coords])	Make supercell.
rotate(**kwargs)	Rotate crystal cell lattice, basis, and unit cell.
save([fname, outpath, structure_format, ...])	Save structure data.
todict()	Return dict of constructor parameters.
transform_lattice(scaling_matrix[, ...])	Transform structure lattice.
translate(t[, fix_anchor_points])	Translate crystal cell lattice, basis, and unit cell.
write(*args, **kwargs)	Write structure data to file.
write_data(**kwargs)	Write LAMMPS data file.
write_dump(**kwargs)	Write LAMMPS dump file.
write_pdb(**kwargs)	Write pdb file.
write_xyz(**kwargs)	Write xyz file.

Methods Summary

generate([finalize])	Generate structure data.
generate_fname([n, m, nx, nz, fix_Lx, fix_Lz])
save([fname, outpath, structure_format, ...])	Save structure data.

Methods Documentation

generate(finalize=True)

Generate structure data.

classmethod generate_fname(n=None, m=None, nx=None, nz=None, fix_Lx=False, fix_Lz=False, **kwargs)

save(fname=None, outpath=None, structure_format=None, center_centroid=True, **kwargs)

Save structure data.

See save method for documentation.