sknano.generators.SWNTGenerator

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

Class for generating SWNT structures.

Parameters:

*Ch : {tuple or ints}

Either a 2-tuple of integers (i.e., *Ch = [(n, m)]) or 2 integers (i.e., *Ch = [n, m]) specifying the chiral indices of the nanotube chiral vector $\mathbf{C}_h = n\mathbf{a}_1 + m\mathbf{a}_2 = (n, m)$.

nz : int, optional

Number of repeat unit cells in the $z$ direction, along the length of the nanotube.

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.

element1, element2 : {str, int}, optional

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.

Lz : float, optional

Length of nanotube in units of nanometers. Overrides the nz value.

New in version 0.2.5.

tube_length : float, optional

Length of nanotube in units of nanometers. Overrides the nz value.

Deprecated since version 0.2.5: Use Lz instead

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.

New in version 0.2.6.

autogen : bool, optional

if True, automatically generate structure data.

verbose : bool, optional

if True, show verbose output

Examples

First, load the SWNTGenerator class.

>>> from sknano.generators import SWNTGenerator

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

>>> swnt = SWNTGenerator((10, 5))
>>> swnt.save(fname='10,5_unit_cell.xyz')
>>> # note that there are two other alternative, but equivalent
>>> # means of passing arguments to SWNTGenerator constructor:
>>> # SWNTGenerator(10, 5) and SWNTGenerator(n=10, m=5)

Here’s a nice ray traced rendering of the generated $(10, 5)$ SWNT unit cell.

Attributes

Ch	SWNT circumference $|\mathbf{C}_h|$ in Å
Ch_vec	SWNT chiral vector.
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_tube	Number of atoms in nanotube $N_{\mathrm{atoms/tube}}$.
Natoms_per_unit_cell	Number of atoms in nanotube unit cell.
Ntubes	Number of nanotubes.
R	Symmetry vector $\mathbf{R} = (p, q)$.
T	Length of nanotube unit cell $|\mathbf{T}|$ in Å.
Tvec	SWNT translation vector.
atoms	Structure StructureAtoms.
basis	NanoStructureBase basis atoms.
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_Lz
fmtstr	Format string.
lattice	Structure Crystal3DLattice.
linear_mass_density	Linear mass density of nanotube in g/nm.
m	Chiral index $m$.
n	Chiral index $n$.
nz	Number of nanotube unit cells along the $z$-axis.
rt	Nanotube radius $r_t = \frac{|\mathbf{C}_h|}{2\pi}$ in Å.
scaling_matrix	CrystalCell.scaling_matrix.
structure	Pointer to self.
structure_data	Alias for BaseStructureMixin.structure.
t1	$t_{1} = \frac{2m + n}{d_{R}}$
t2	$t_2 = -\frac{2n + m}{d_R}$
tube_length	Alias for SWNT.Lz
tube_mass	SWNT mass in grams.
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 BaseStructureMixin.atoms.
generate()	Generate structure data.
generate_fname([n, m, nz, fix_Lz])
generate_unit_cell()	Generate the nanotube unit cell.
make_supercell(scaling_matrix[, wrap_coords])	Make supercell.
read_data(*args, **kwargs)
read_dump(*args, **kwargs)
read_xyz(*args, **kwargs)
rotate(**kwargs)	Rotate crystal cell lattice, basis, and unit cell.
save([fname, outpath, structure_format, ...])	Save structure data.
todict()	Return dict of SWNT attributes.
transform_lattice(scaling_matrix[, ...])
translate(t[, fix_anchor_points])	Translate crystal cell basis.
write_data(**kwargs)
write_dump(**kwargs)
write_xyz(**kwargs)