UnrolledSWNT

class sknano.core.structures.UnrolledSWNT(*args, nx=1, Lx=None, fix_Lx=False, **kwargs)

Bases: sknano.core.structures.UnrolledSWNTBase, sknano.core.structures.NanoStructureBase

Unrolled SWNT structure class.

Parameters:

• *Ch –

  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 \(\mathbf{C}_h = n\mathbf{a}_1 + m\mathbf{a}_2 = (n, m)\).

• nx (int, optional) – Number of repeat unit cells in the \(x\) direction, along the unrolled chiral vector.
• 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.

• element2 (element1,) –

  Element symbol or atomic number of basis Atoms 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.
• nlayers (int, optional) – Number of layers (default: 1)
• layer_spacing (float, optional) – Distance between layers in Angstroms (default: 3.4).
• stacking_order ({'AA', 'AB'}, optional) – Stacking order of layers.
• layer_rotation_angles (list, optional) – list of rotation angles for each layer in degrees if degrees is True (default), otherwise in radians. The list length must equal the number of layers.
• layer_rotation_increment (float, optional) – incremental layer rotation angle in degrees if degrees is True (default), otherwise in radians. Each subsequent layer will be rotated by layer_rotation_increment relative to the layer below it.
• Lx (float, optional) –

  Length of the unrolled swnt sheet along the chiral vector in units of Angstroms. Overrides the nx value.

  Changed in version 0.4.0: Changed units from nanometers to Angstroms

• fix_Lx (bool, optional) – Generate the unrolled swnt sheet with the length along the chiral vector as close to the specified \(L_x\) as possible. If True, then non integer \(n_x\) cells are permitted.
• Lz (float, optional) –

  Length of the unrolled swnt sheet along the translation vector in units of Angstroms. Overrides the nz value.

  Changed in version 0.4.0: Changed units from nanometers to Angstroms

• fix_Lz (bool, optional) – Generate the unrolled swnt sheet with the length along the translation vector as close to the specified \(L_z\) as possible. If True, then non integer \(n_z\) cells are permitted.
• verbose (bool, optional) – if True, show verbose output

Examples

>>> from sknano.core.structures import UnrolledSWNT
>>> unrolled_swnt = UnrolledSWNT(10, 5)
>>> unrolled_swnt
UnrolledSWNT((10, 5), nx=1, nz=1, bond=1.42, basis=['C', 'C'], nlayers=1,
layer_spacing=3.4, stacking_order='AB')

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	Number of atoms in nanotube.
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	SWNT mass in grams.
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.
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.
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.

Methods Summary

generate_unit_cell()

Generate the nanotube unit cell.

Methods Documentation

generate_unit_cell()

Generate the nanotube unit cell.