sknano.generators.UnrolledSWNTGenerator

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

Class for generating unrolled nanotube structures.

New in version 0.2.23.

Parameters:

n, m : int

Chiral indices defining the nanotube chiral vector \(\mathbf{C}_{h} = n\mathbf{a}_{1} + m\mathbf{a}_{2} = (n, m)\).

nx, ny, nz : int, optional

Number of repeat unit cells in the \(x, y, z\) dimensions

element1, element2 : {str, int}, optional

Element symbol or atomic number of basis Atom 1 and 2

bond : float, optional

\(\mathrm{a}_{\mathrm{CC}} =\) distance between nearest neighbor atoms. Must be in units of Angstroms.

Lx, Ly, Lz : float, optional

Length of bundle in \(x, y, z\) dimensions in nanometers. Overrides the \(n_x, n_y, n_z\) cell values.

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_unit_cell, followed by generate_structure_data.

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.

>>> flatswcnt = UnrolledSWNTGenerator(n=10, m=5)
>>> flatswcnt.save_data()

The rendered structure looks like:

Attributes

Ch	SWNT circumference \(|\mathbf{C}_h|\) in Å
Lx
Ly
Lz	SWNT length \(L_z = L_{\mathrm{tube}}\) in nanometers.
M	\(M = np - nq\)
N	Number of graphene hexagons in nanotube unit cell.
Natoms	Number of atoms in nanotube.
Natoms_per_unit_cell	Number of atoms in nanotube unit cell.
Nlayers	Number of layers.
R	Symmetry vector \(\mathbf{R} = (p, q)\).
T	Length of nanotube unit cell \(|\mathbf{T}|\) in Å.
atoms	Return structure Atoms.
bond	Bond length in Å.
chiral_angle	Chiral angle \(\theta_c\) in degrees.
chiral_type
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	Element symbol of Atom 1.
element2	Element symbol of Atom 2.
fix_Lx
fix_Lz
m	Chiral index \(m\).
n	Chiral index \(n\).
nx	Number of unit cells along the \(x\)-axis.
nz	Number of nanotube unit cells along the \(z\)-axis.
rt	Nanotube radius \(r_t = \frac{|\mathbf{C}_h|}{2\pi}\) in Å.
structure	Alias to structure_data.
structure_data	Return StructureData instance.
t1	\(t_{1} = \frac{2m + n}{d_{R}}\)
t2	\(t_2 = -\frac{2n + m}{d_R}\)
unit_cell_mass	Unit cell mass in atomic mass units.
unit_cell_symmetry_params

Methods

generate_structure_data()	Generate structure data.
generate_unit_cell()	Generate the nanotube unit cell.
save_data([fname, outpath, ...])	Save structure data.